TWI864384B - Open-back headphones - Google Patents

Abstract

The present disclosure may disclose an open-back headphone, including: a fixed structure, configured to fix the headphone at the position near the user’s ears and does not block the ear channel; and a shell structure, configured to bear: a first microphone array configured to collect environmental noise; at least one speaker array; and a signal processor configured to: estimate the noise of a first space position based on the collected environmental noise, the first space position is closer to the user’s ear channel than any microphone in the first microphone array; and generate denoise signal based on the noise of the first space position, so that the at least one speaker array may output a denoise wave according to the denoise signal, and the denoise wave may be used to eliminate the environmental noise transmitted to the user’s ear channel.

Description

Open headphones

This application relates to the field of acoustics, and in particular to an open-type headphone.

This application claims priority to international patent application No. PCT/CN2021/089670 filed on April 25, 2021, the entire contents of which are incorporated herein by reference.

Headphones allow users to listen to audio content and make voice calls while ensuring the privacy of user interactions, and they do not disturb people around them. Headphones can generally be divided into two categories: in-ear headphones and open-ear headphones. In-ear headphones block the user's ears during use, and users are prone to blockage, foreign objects, bloating, and other feelings when wearing them for a long time. Open-ear headphones open the user's ears, which is conducive to long-term wear, but when the external noise is large, the noise reduction effect is not obvious, resulting in a poor listening experience for the user.

Therefore, it is desirable to provide an open-type headset that can open the user's ears and improve the user's listening experience.

An embodiment of the present invention provides an open-type earphone, comprising: a fixing structure, configured to fix the earphone at a position near the ear of a user without blocking the ear canal of the user; a housing structure, configured to carry: a first microphone array, configured to pick up environmental noise; at least one speaker array; and a signal processor, configured to: estimate noise at a first spatial position based on the picked up environmental noise, the first spatial position being closer to the ear canal of the user than any microphone in the first microphone array; and generate a noise reduction signal based on the noise at the first spatial position, so that the at least one speaker array outputs a noise reduction wave according to the noise reduction signal, and the noise reduction wave is used to eliminate the environmental noise transmitted to the ear canal of the user.

In some embodiments, the housing structure is configured to accommodate a second microphone array, the second microphone array is configured to pick up the ambient noise and the noise reduction wave, the second microphone array is at least partially different from the first microphone array; and the signal processor is configured to update the noise reduction signal based on the sound signal picked up by the second microphone array.

In some embodiments, updating the noise reduction signal based on the sound signal picked up by the second microphone array includes: estimating the sound field at the ear canal of the user based on the sound signal picked up by the second microphone array; and adjusting parameter information of the noise reduction signal according to the sound field at the ear canal of the user.

In some embodiments, the second microphone array includes a microphone that is closer to the user's ear canal than any microphone in the first microphone array.

In some embodiments, the signal processor estimates the noise of the first spatial position based on the picked-up environmental noise, including: performing signal separation according to the picked-up environmental noise, obtaining parameter information corresponding to the environmental noise, and generating the noise reduction signal based on the parameter information.

In some embodiments, the signal processor estimates the noise of the first spatial position based on the picked-up environmental noise, including: determining one or more spatial noise sources related to the picked-up environmental noise; and estimating the noise of the first spatial position based on the spatial noise sources.

In some embodiments, determining one or more of the spatial noise sources associated with the picked-up ambient noise includes: dividing the picked-up ambient noise into a plurality of sub-bands, each sub-band corresponding to a different frequency range; and determining, on at least one sub-band, the spatial noise source corresponding thereto.

In some embodiments, the first microphone array includes a first sub-microphone array and a second sub-microphone array, the first sub-microphone array and the second sub-microphone array are respectively located at the left ear and the right ear of the user, and determining the spatial noise source corresponding to the at least one sub-band includes: obtaining a user head function, the user head function reflects the reflection or absorption of sound by the user's head; and on the at least one sub-band, combining the environmental noise picked up by the first sub-microphone array, the environmental noise picked up by the second sub-microphone array, and the user head function to determine the spatial noise source corresponding thereto.

In some embodiments, the first microphone array includes a noise microphone, the at least one speaker array forms at least one set of acoustic dipoles, and the noise microphone is located at an acoustic zero point of the dipole radiation field.

In some embodiments, the at least one microphone array includes a bone conduction microphone, which is configured to pick up the user's speaking sound, and the signal processor estimates the noise of the first spatial position based on the picked up environmental noise, including: removing components associated with the signal picked up by the bone conduction microphone from the picked up environmental noise to update the environmental noise; and estimating the noise of the first spatial position based on the updated environmental noise.

In some embodiments, the at least one microphone array includes a bone conduction microphone and an air conduction microphone, and the signal processor controls the switching state of the bone conduction microphone and the air conduction microphone based on the working state of the headset.

In order to more clearly explain the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present invention. For those with ordinary knowledge in the relevant technical field, the present invention can also be applied to other similar scenarios based on these drawings without making any progressive efforts. Unless it is obvious from the language environment or otherwise explained, the same element symbols in the drawings represent the same structure or operation.

It should be understood that the "system", "device", "unit" and/or "module" used herein are a method for distinguishing different elements, components, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As shown in the present invention and the scope of the patent application, unless the context clearly indicates an exception, the words "a", "an", "an" and/or "the" do not specifically refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or apparatus may also include other steps or elements.

Flowcharts are used in the present invention to illustrate the operations performed by the system according to the embodiments of the present invention. It should be understood that the preceding or succeeding operations are not necessarily performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more steps of operations may be removed from these processes.

Open-type headphones are headphone devices that can open the user's ears. Open-type headphones can fix the speakers near the user's ears and do not block the user's ear canal through a fixed structure (for example, ear hooks, head hooks, etc.). When the user uses open-type headphones, the external environmental noise can also be heard by the user, which makes the user's listening experience poor. For example, in a place with loud external environmental noise (for example, streets, scenic spots, etc.), when the user uses open-type headphones to play music, the noise of the external environment will directly enter the user's ear canal, causing the user to hear loud environmental noise, and the environmental noise will interfere with the user's listening experience. For another example, when the user wears open-type headphones to make a call, the microphone will not only pick up the user's own voice, but also pick up environmental noise, making the user's call experience poor.

Based on the above problems, an open-type headset is provided in an embodiment of the present specification. In some embodiments, the open-type headset may include a fixing structure, a housing structure, a first microphone array, at least one speaker array, and a signal processor. The fixing structure is configured to fix the open-type headset near the user's ear without blocking the user's ear canal. The housing structure is configured to accommodate the first microphone array, at least one speaker array, and the signal processor. The first microphone array is configured to pick up environmental noise. The signal processor is configured to estimate the noise at the first spatial position based on the environmental noise picked up by the first microphone array, and generate a noise reduction signal based on the noise at the first spatial position, where the first spatial position is closer to the user's ear canal than any microphone in the first microphone array. It can be understood here that the microphones in the first microphone array can be distributed at different positions near the user's ear canal, and the noise near the user's ear canal position (for example, the first spatial position) is estimated by the environmental noise signal collected by each microphone in the first microphone array. At least one speaker array is configured to output a noise reduction wave based on the noise reduction signal, and the noise reduction wave can be used to eliminate the environmental noise transmitted to the user's ear canal. In some embodiments, the open-type headphones may further include a second microphone array, which is configured to pick up environmental noise and noise reduction waves output by at least one speaker array. In some embodiments, the signal processor may update the noise reduction signal based on the sound signal picked up by the second microphone array. For example, the signal processor may estimate the sound field at the user's ear canal based on the sound signal picked up by the second microphone array, and adjust the phase or amplitude of the noise reduction signal according to the sound field at the user's ear canal to achieve the update of the noise reduction signal. In the embodiments of the present specification, the environmental noise in the ear canal of the user is eliminated by using the noise reduction wave through the above method, thereby realizing active noise reduction of the open-type headphones and improving the user's auditory experience when using the open-type headphones.

Fig. 1 is an exemplary block diagram of an open-type earphone provided according to some embodiments of the present invention. As shown in Fig. 1, the open-type earphone 100 may include a housing structure 110, a first microphone array 130, a signal processor 140, and a speaker array 150, wherein the first microphone array 130, the signal processor 140, and the speaker array 150 are located at the housing structure 110. The open-type earphone 100 can be fixed near the ear of the user through the fixing structure 120 without blocking the ear canal of the user. In some embodiments, the first microphone array 130 located at the housing structure 110 can pick up the environmental noise at the user's ear canal, and convert the picked up environmental noise signal into an electrical signal and transmit it to the signal processor 140 for signal processing. The signal processor 140 is coupled to the first microphone array 130 and the speaker array 150. The signal processor 140 receives the environmental noise signal picked up by the first microphone array 130 and performs signal processing on it to obtain parameter information (e.g., amplitude information, phase information, etc.) of the environmental noise. The signal processor 140 can estimate the noise at the first spatial position of the user based on the parameter information (e.g., amplitude information, phase information, etc.) of the ambient noise, and generate a noise reduction signal based on the noise at the first spatial position. The parameter information of the noise reduction signal corresponds to the parameter information of the ambient noise, for example, the amplitude of the noise reduction signal is approximately equal to the amplitude of the ambient noise, and the phase of the noise reduction signal is approximately opposite to the phase of the ambient noise. The signal processor 140 transmits the generated noise reduction signal to the speaker array 150. The speaker array 150 can output a noise reduction wave according to the noise reduction signal generated by the signal processor 140. The noise reduction wave can offset the ambient noise at the user's ear canal, thereby realizing active noise reduction of the open-type earphones 100 and improving the user's auditory experience when using the open-type earphones 100.

The housing structure 110 may be configured to carry the first microphone array 130, the signal processor 140, and the speaker array 150. In some embodiments, the housing structure 110 may be a closed or semi-closed housing structure with a hollow interior, and the first microphone array 130, the signal processor 140, and the speaker array 150 are located at the housing structure 110. In some embodiments, the housing structure 110 may be a three-dimensional structure of a regular or irregular shape such as a cuboid, a cylinder, or a frustum. When the user wears the open-ear headphones 100, the housing structure 110 can be located near the user's ear, for example, the housing structure 110 can be located around the user's auricle (for example, the front side or the back side), or located on the user's ear but not blocking or covering the user's ear canal. In some embodiments, the open-ear headphones 100 can be bone conduction headphones, and at least one side of the housing structure 110 can be in contact with the user's head skin. In bone conduction headphones, an acoustic driver (for example, a vibrating speaker) converts an audio signal into mechanical vibration, which can be transmitted to the user's auditory nerve through the housing structure 110 and the user's bones. In some embodiments, the open-type earphone 100 may be an air conduction earphone, and at least one side of the housing structure 110 may or may not be in contact with the user's head skin. The side wall of the housing structure 110 includes at least one sound-conducting hole, and the speaker in the air conduction earphone converts the audio signal into air-conducted sound, which can be radiated toward the user's ear through the sound-conducting hole.

The first microphone array 130 may be configured to pick up environmental noise. In some embodiments, environmental noise refers to a combination of multiple external sounds in the environment in which the user is located. In some embodiments, environmental noise may include one or more of traffic noise, industrial noise, construction noise, social noise, etc. In some embodiments, traffic noise may include but is not limited to driving noise of motor vehicles, whistle noise, etc. Industrial noise may include but is not limited to factory power machinery operation noise, etc. Construction noise may include but is not limited to power machinery excavation noise, drilling noise, stirring noise, etc. Social life environmental noise may include but is not limited to crowd gathering noise, entertainment propaganda noise, crowd noise, household appliance noise, etc. In some embodiments, the first microphone array 130 may be arranged near the user's ear canal to pick up the environmental noise transmitted to the user's ear canal. The first microphone array 130 may convert the picked up environmental noise signal into an electrical signal and transmit it to the signal processor 140 for signal processing. In some embodiments, the environmental noise may also include the sound of the user speaking. For example, when the open-type headset 100 is not in a call state, the sound generated by the user's own speech can also be regarded as environmental noise. The first microphone array 130 can pick up the sound of the user's own speech and other environmental noise, and convert the sound signal generated by the user's speech and other environmental noise into an electrical signal and transmit it to the signal processor 140 for signal processing. In some embodiments, the first microphone array 130 can be distributed at the left ear or right ear of the user. In some embodiments, the first microphone array 130 can also be located at the left ear and the right ear of the user. For example, the first microphone array 130 may include a first sub-microphone array and a second sub-microphone array, wherein the first sub-microphone array is located at the left ear of the user, and the second sub-microphone array is located at the right ear of the user, and the first sub-microphone array and the second sub-microphone array may enter the working state at the same time or one of them may enter the working state.

In some embodiments, the first microphone array 130 may include an air conduction microphone and/or a bone conduction microphone. For example, in some embodiments, the first microphone array 130 may include one or more air conduction microphones. For example, when a user uses the open-ear headphones 100 to listen to music, the air conduction microphone may simultaneously obtain the noise of the external environment and the sound of the user speaking and convert it into an electrical signal as environmental noise and transmit it to the signal processor 140 for processing. In some embodiments, the first microphone array 130 may also include one or more bone conduction microphones. In some embodiments, the bone conduction microphone may be in direct contact with the user's head skin, and the vibration signal generated by the facial bones or muscles when the user speaks may be directly transmitted to the bone conduction microphone, and then the bone conduction microphone converts the vibration signal into an electrical signal, and transmits the electrical signal to the signal processor 140 for signal processing. In some embodiments, the bone conduction microphone may not be in direct contact with the human body, and the vibration signal generated by the facial bones or muscles when the user speaks may be first transmitted to the shell structure 110, and then transmitted from the shell structure 110 to the bone conduction microphone, and the bone conduction microphone further converts the human body vibration signal into an electrical signal containing voice information. For example, when the user is on a call, the signal processor 140 can treat the sound signal collected by the air conduction microphone as environmental noise for noise reduction processing, and retain the sound signal collected by the bone conduction microphone as a voice signal, thereby ensuring the call quality of the user. In some embodiments, according to the working principle of the microphone as a classification, the first microphone array 130 can include a dynamic microphone, a ribbon microphone, a capacitive microphone, a stationary microphone, an electromagnetic microphone, a carbon microphone, etc., or any combination thereof. In some embodiments, the array arrangement of the first microphone array 130 may be a linear array (e.g., straight line, curve), a planar array (e.g., regular and/or irregular shapes such as a cross, circle, ring, polygon, mesh, etc.), or a three-dimensional array (e.g., cylindrical, spherical, hemispherical, polyhedral, etc.). For details on the arrangement of the first microphone array 130, please refer to FIG. 8 and related contents of this specification.

The signal processor 140 is configured to estimate the noise at the first spatial position based on the environmental noise picked up by the first microphone array 130, and generate a noise reduction signal based on the noise at the first spatial position. The first spatial position refers to a spatial position at a specific distance close to the user's ear canal, and the first spatial position is closer to the user's ear canal than any microphone in the first microphone array 130. The specific distance here can be a fixed distance, for example, 0.5 cm, 1 cm, 2 cm, 3 cm, etc. In some embodiments, the first spatial position is related to the distribution position and quantity of each microphone in the first microphone array 130 relative to the user's ear, and the first spatial position can be adjusted by adjusting the distribution position and/or quantity of each microphone in the first microphone array 130 relative to the user's ear. For example, by increasing the number of microphones in the first microphone array 130, the first spatial position can be closer to the user's ear canal.

The signal processor 140 may perform signal processing on the received ambient noise signal to estimate the noise at the first spatial position. In some embodiments, the signal processor 140 may be coupled to the first microphone array 130 and the speaker array 150, and the signal processor 140 may receive the ambient noise picked up by the first microphone array 130 to estimate the noise at the first spatial position. For example, the signal processor 140 may determine one or more spatial noise sources related to the picked up ambient noise. For another example, the signal processor 140 may perform azimuth estimation, phase information estimation, amplitude information estimation, etc. on the spatial noise sources related to the ambient noise. The signal processor 140 may generate a noise reduction signal based on the noise estimation (eg, phase information, amplitude information) of the first spatial position. The noise reduction signal refers to a sound signal having an amplitude approximately equal to that of the noise of the first spatial position and an approximately opposite phase.

The speaker array 150 is configured to output a noise reduction wave based on the noise reduction signal, and the noise reduction wave is used to eliminate the environmental noise transmitted to the user's ear canal. In some embodiments, the speaker array 150 can be disposed at the housing structure 110, and when the user wears the open-type headphones 100, the speaker array 150 can be located near the user's ears. In some embodiments, the speaker array 150 can output a noise reduction wave based on the noise reduction signal to offset the environmental noise at the first spatial position. For example, the signal processor 140 controls the speaker array 150 to output a sound signal with an amplitude approximately equal to the noise at the first spatial position and an approximately opposite phase to the noise at the first spatial position to cancel the noise at the first spatial position. In some embodiments, the distance between the first spatial position and the ear canal of the user is relatively small, and the noise at the first spatial position can be approximately regarded as the noise transmitted to the ear of the user. The noise reduction wave output by the speaker array 150 based on the noise reduction signal can cancel the noise at the first spatial position, and it can be approximately regarded as the environmental noise transmitted to the ear canal of the user is eliminated. In some embodiments, the speaker array 150 may include one or more of an electrodynamic speaker (e.g., a dynamic speaker), a magnetic speaker, an ionic speaker, an electrostatic speaker (or a capacitive speaker), a piezoelectric speaker, etc., based on the working principle of the speaker. In some embodiments, the speaker array 150 may include an air conduction speaker or a bone conduction speaker, based on the propagation mode of the sound output by the speaker. For example, when the speaker array 150 includes only air conduction speakers, some of the air conduction speakers in the speaker array 150 can be used to output noise reduction waves to eliminate noise, and other air conduction speakers in the speaker array 150 can be used to transmit sound information that the user needs to hear (e.g., device media audio, call remote audio). In some embodiments, the speakers in the speaker array 150 that are used to transmit sound information that the user needs to hear to the user can also be used to output noise reduction waves. For another example, when the speaker array 150 includes a bone conduction speaker and an air conduction speaker, the air conduction speaker can be used to output a noise reduction wave to eliminate noise, and the bone conduction speaker can be used to transmit the sound information that the user needs to hear to the user. Compared with the air conduction speaker, the bone conduction speaker transmits mechanical vibrations directly to the user's auditory nerve through the user's body (e.g., bones, skin tissue, etc.), and in this process, the interference to the air conduction microphone that picks up environmental noise is relatively small. The bone conduction speaker will cause the housing structure 110 to generate mechanical vibrations when transmitting mechanical vibrations to the user. The mechanical vibrations generated by the housing structure 110 act on the air to generate air-conducted sound. In some embodiments, the air-conducted sound generated by the housing structure 110 can also serve as noise reduction waves. It should be noted that in some embodiments, the speaker array 150 can be an independent functional device or a part of a single device that can realize multiple functions. In some embodiments, the signal processor 140 can be integrated with the speaker array 150 and/or formed as a whole. In some embodiments, the speaker array 150 may be arranged in a linear array (e.g., straight line, curve), a planar array (e.g., regular and/or irregular shapes such as a cross, mesh, circle, ring, polygon, etc.), or a three-dimensional array (e.g., cylindrical, spherical, hemispherical, polyhedron, etc.), which is not limited in this specification.

In some embodiments, the open-type earphones 100 may further include a fixing structure 120, which is configured to fix the open-type earphones 100 near the user's ears without blocking the user's ear canal. In some embodiments, the fixing structure 120 may include an ear hook, a headband, or an elastic band, so that the open-type earphones 100 can be better fixed near the user's ears to prevent the user from falling off during use. For example, the fixing structure 120 may be an ear hook, which may be configured to be worn around the ear area. For another example, the fixing structure 120 may be a neck strap, which may be configured to be worn around the neck/shoulder area. In some embodiments, the ear hook can be a continuous hook and can be elastically stretched to be worn on the user's ear. At the same time, the ear hook can also apply pressure to the user's auricle so that the open-type earphone 100 is firmly fixed to a specific position of the user's ear or head. In some embodiments, the ear hook can be a discontinuous strip. For example, the ear hook can include a rigid part and a flexible part, wherein the rigid part can be made of a rigid material (e.g., plastic or metal), and the rigid part can be fixed to the housing structure of the acoustic output device by physical connection (e.g., snap connection, thread connection, etc.). The flexible part can be made of an elastic material (e.g., cloth, composite material, or/and neoprene).

It should be noted that the above description of FIG. 1 and FIG. 2 is provided for illustrative purposes only and is not intended to limit the scope of the present invention. For those having ordinary knowledge in the art, various changes and modifications can be made according to the guidance of the disclosure of this case. However, these changes and modifications will not deviate from the scope of the present invention. For example, one or more elements (e.g., the fixing structure 120, etc.) in the open-type earphone 100 can be omitted. In some embodiments, an element can be replaced by other elements that can achieve similar functions. For example, in some embodiments, the open-type earphone 100 may not include the fixing structure 120, and the housing structure 110 may be a housing structure having a shape that fits the human ear, such as a ring, an ellipse, a polygon (regular or irregular), a U-shape, a V-shape, or a semicircle, so that the housing structure 110 can be hung near the user's ear. In some embodiments, one element may be split into multiple sub-elements, or multiple elements may be combined into a single element.

FIG. 2 is an exemplary principle flow chart of an open-ear headset provided according to some embodiments of the present invention. As shown in FIG. 2 , process 200 may include:

In step 210, environmental noise is picked up.

In some embodiments, this step may be performed by the first microphone array 130. In some embodiments, environmental noise refers to a combination of multiple external sounds in the environment in which the user is located. In some embodiments, environmental noise may include one or more of traffic noise, industrial noise, construction noise, social noise, etc. In some embodiments, traffic noise may include but is not limited to driving noise of motor vehicles, whistle noise, etc. Industrial noise may include but is not limited to factory power machinery operation noise, etc. Construction noise may include but is not limited to power machinery excavation noise, drilling noise, stirring noise, etc. Social life environmental noise may include but is not limited to crowd gathering noise, entertainment propaganda noise, crowd noise, household appliance noise, etc. In some embodiments, the first microphone array 130 may be located near the user's ear canal to pick up the environmental noise transmitted to the user's ear canal. The first microphone array 130 may convert the picked up environmental noise signal into an electrical signal and transmit it to the signal processor 140 for signal processing. In some embodiments, environmental noise may also include the sound of the user speaking. For example, when the open-ear headphones 100 are not in a call state (for example, when listening to audio or watching video), the sound generated by the user's own speech can also be regarded as environmental noise. The first microphone array 130 can pick up the sound of the user's own speech and other environmental noise, and convert the sound signal generated by the user's speech and other environmental noise into an electrical signal and transmit it to the signal processor 140 for signal processing.

In step 220, noise at a first spatial location is estimated based on the picked-up ambient noise.

In some embodiments, this step may be performed by the signal processor 140. The first spatial position refers to a spatial position at a specific distance from the user's ear canal. The specific distance here may be a fixed distance, for example, 0.5 cm, 1 cm, 2 cm, 3 cm, etc., and may be adaptively adjusted according to actual application conditions. The environmental noise picked up by the first microphone array 130 may be from different directions and different types of spatial noise sources, so the parameter information (for example, phase information, amplitude information) corresponding to each spatial noise source is different. In some embodiments, the signal processor 140 may perform signal separation and extraction on the noise at the first spatial position according to the statistical distribution and structured features of different types of noise in different dimensions (e.g., spatial domain, time domain, frequency domain, etc.), thereby estimating different types of noise (e.g., different frequencies, different phases, etc.), and estimating parameter information corresponding to each type of noise (e.g., amplitude information, phase information, etc.). In some embodiments, the signal processor 140 may also determine the overall parameter information of the noise at the first spatial position according to the parameter information corresponding to different types of noise at the first spatial position. In some embodiments, estimating the noise at the first spatial position based on the picked-up ambient noise may also include determining one or more spatial noise sources related to the picked-up ambient noise, and estimating the noise at the first spatial position based on the spatial noise sources. For example, the picked-up ambient noise is divided into a plurality of sub-bands, each sub-band corresponds to a different frequency range, and a spatial noise source corresponding thereto is determined on at least one sub-band. It should be noted that the spatial noise source estimated by the sub-band here is a virtual noise source corresponding to a real external noise source. For the specific content of estimating the noise at the first spatial position based on the picked-up ambient noise, reference may be made to other places in the specification of the present invention, for example, Figures 5 to 7 and their corresponding descriptions.

The open-type earphone 100 does not block the user's ear canal, and cannot obtain environmental noise by setting a microphone at the ear canal. The first spatial position is a spatial area constructed by the first microphone array 130 to simulate the position of the user's ear canal. In order to more accurately estimate the environmental noise transmitted at the user's ear canal, in some embodiments, the first spatial position is closer to the user's ear canal than any microphone in the first microphone array 130. In some embodiments, the first spatial position is related to the distribution position and quantity of each microphone in the first microphone array 130 relative to the user's ear. The first spatial position can be adjusted by adjusting the distribution position or quantity of each microphone in the first microphone array 130 relative to the user's ear. For example, the first spatial position can be brought closer to the user's ear canal by increasing the number of microphones in the first microphone array 130. For another example, the first spatial position can be brought closer to the user's ear canal by reducing the distance between the microphones in the first microphone array 130. For another example, the first spatial position can be brought closer to the user's ear canal by changing the arrangement of the microphones in the first microphone array 130.

In step 230, a noise reduction signal is generated based on the noise at the first spatial location.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the signal processor 140 may generate a noise reduction signal based on the parameter information (e.g., amplitude information, phase information, etc.) of the noise at the first spatial position obtained in step 220. For example, the phase of the noise reduction wave may be approximately opposite to the phase of the noise at the first spatial position. For another example, the phase of the noise reduction wave may be approximately opposite to the phase of the noise at the first spatial position, and the amplitude of the noise reduction signal may be approximately equal to the amplitude of the noise at the first spatial position. In some embodiments, the speaker array 150 may output a noise reduction wave based on the noise reduction signal generated by the signal processor 140, and the noise reduction wave may cancel each other with the noise at the first spatial position. In some embodiments, the noise at the first spatial position can be approximately regarded as the noise at the user's ear canal position, so the noise reduction signal and the noise at the first spatial position cancel each other out, which can be approximately regarded as the environmental noise transmitted to the user's ear canal being eliminated. In some embodiments, the open-type earphone 100 can eliminate the environmental noise at the user's ear canal position through the method steps described in FIG. 2 to achieve active noise reduction of the open-type earphone 100.

It should be noted that the above description of process 200 is for example and explanation only, and does not limit the scope of application of this specification. For those with ordinary knowledge in the relevant technical field, various modifications and changes can be made to process 200 under the guidance of this specification. However, these modifications and changes are still within the scope of this specification. For example, steps in process 200 can also be added, omitted or merged, for example, signal processing (for example, filtering processing, etc.) can also be performed on environmental noise.

Continuing with reference to FIG. 1 , in some embodiments, the open-type earphone 100 may further include a second microphone array 160. The second microphone array 160 may be located inside the housing structure 110. In some embodiments, the second microphone array 160 is at least partially different from the first microphone array 130. For example, the microphones in the second microphone array 160 are different from the microphones in the first microphone array 130 in one or more of the number, type, location, and arrangement. In some embodiments, for example, the arrangement of the microphones in the first microphone array 130 may be linear, and the arrangement of the microphones in the second microphone array 160 may be circular. For another example, the microphones in the second microphone array 160 may include only air conduction microphones, and the first microphone array 130 may include air conduction microphones and bone conduction microphones. In some embodiments, the microphones in the second microphone array 160 may be any one or more microphones included in the first microphone array 130, and the microphones in the second microphone array 160 may also be independent of the microphones in the first microphone array 130. In some embodiments, the second microphone array 160 may be configured to pick up environmental noise and noise reduction waves output by the speaker array 150. The ambient noise and noise reduction waves picked up by the second microphone array 160 may be transmitted to the signal processor 140. In some embodiments, the signal processor 140 may update the noise reduction signal based on the sound signal picked up by the second microphone array 160. For example, the signal processor 140 may adjust the parameter information of the noise reduction signal according to the parameter information (e.g., frequency information, amplitude information, phase information, etc.) of the sound signal picked up by the second microphone array 160, so that the amplitude of the adjusted noise reduction signal can be more consistent with the amplitude of the noise at the first spatial position, or the phase of the adjusted noise reduction signal can be more consistent with the anti-phase of the phase of the noise at the first spatial position, so that the updated noise reduction wave and the noise at the first spatial position can be more completely offset. For the specific content of updating the noise reduction signal based on the sound signal picked up by the second microphone array 160, please refer to FIG. 3 of this specification and its related description.

FIG3 is an exemplary flow chart of updating a noise reduction signal according to some embodiments of the present invention. As shown in FIG3, process 300 may include:

In step 310, the sound field at the user's ear canal is estimated based on the sound signal picked up by the second microphone array 160.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the sound signal picked up by the second microphone array 160 includes the ambient noise and the noise reduction wave output by the speaker array 150. In some embodiments, after the ambient noise and the noise reduction wave output by the speaker array 150 cancel each other out, there may still be a portion of the sound signal near the user's ear canal that has not been canceled out. These uncancelled sound signals may be residual ambient noise and/or residual noise reduction wave, so that after the ambient noise and the noise reduction wave cancel each other out, there is still a certain amount of noise in the user's ear canal. The signal processor 140 can perform signal processing based on the sound signal (e.g., environmental noise, noise reduction wave) picked up by the second microphone array 160 to obtain parameter information of the sound field at the user's ear canal, such as frequency information, amplitude information, and phase information, thereby estimating the sound field at the user's ear canal.

In step 320, parameter information of the noise reduction signal is adjusted according to the sound field at the user's ear canal.

In some embodiments, step 320 may be performed by the signal processor 140. In some embodiments, the signal processor 140 may adjust the parameter information (e.g., frequency information, amplitude information, and/or phase information) of the noise reduction signal according to the parameter information of the sound field at the user's ear canal obtained in step 310, so that the amplitude information and frequency information of the updated noise reduction signal are more consistent with the amplitude information and frequency information of the ambient noise at the user's ear canal, and the phase information of the updated noise reduction signal is more consistent with the anti-phase information of the ambient noise at the user's ear canal, so that the updated noise reduction signal can eliminate the ambient noise more accurately.

It should be noted that the above description of process 300 is for example and explanation only, and does not limit the scope of application of this specification. For those with ordinary knowledge in the relevant technical field, various modifications and changes can be made to process 300 under the guidance of this specification. However, these modifications and changes are still within the scope of this specification. For example, the microphone array that picks up the sound field at the user's ear canal is not limited to the second microphone array, but may also include other microphone arrays, such as the third microphone array, the fourth microphone array, etc., and the relevant parameter information of the sound field at the user's ear canal picked up by multiple microphone arrays can be used to estimate the sound field at the user's ear canal by averaging or weighted algorithms.

In some embodiments, in order to more accurately obtain the sound field at the user's ear canal, the second microphone array 160 includes a microphone that is closer to the user's ear canal than any microphone in the first microphone array 130. In some embodiments, the sound signal picked up by the first microphone array 130 is environmental noise, and the sound signal picked up by the second microphone array 160 is environmental noise and noise reduction waves. In some embodiments, the signal processor 140 can estimate the sound field at the user's ear canal based on the sound signal picked up by the second microphone array 160 to update the noise reduction signal. The second microphone array 160 needs to monitor the sound field at the user's ear canal after the noise reduction signal and the environmental noise are offset. The second microphone array 160 includes a microphone that is closer to the user's ear canal than any microphone in the first microphone array 130, which can more accurately represent the sound signal heard by the user. By estimating the sound field of the second microphone array 160 to update the noise reduction signal, the noise reduction effect and the user's auditory experience can be further improved.

In some embodiments, the first microphone array 130 and the second microphone array 160 may be arranged in the same manner. Here, the first microphone array 130 and the second microphone array 160 being arranged in the same manner may be understood as having approximately the same arrangement shape. FIG. 4A is an exemplary layout diagram of the arrangement manner and positional relationship of the first microphone array and the second microphone array provided according to some embodiments of the present invention. As shown in FIG4A , the first microphone array 130 is arranged at the human ear in a semicircular arrangement, and the second microphone array 160 is also arranged at the human ear in a semicircular arrangement, and the microphones in the second microphone array 160 are closer to the user's ear canal than any microphone in the first microphone array 130. In some embodiments, the microphones in the first microphone array 130 can be independently arranged from the microphones in the second microphone array 160. For example, in FIG4A , the microphones in the first microphone array 130 are arranged in a semicircular arrangement, and the microphones in the second microphone array 160 are arranged in a semicircular arrangement, and the microphones in the first microphone array 130 do not overlap or cross with the microphones in the second microphone array 160. In some embodiments, the microphones in the first microphone array 130 may partially overlap or cross with the microphones in the second microphone array 160.

In some embodiments, the first microphone array 130 and the second microphone array 160 may be arranged differently. FIG4B is an exemplary layout diagram of the arrangement of the first microphone array and the second microphone array provided according to other embodiments of the present invention. As shown in FIG4B , the first microphone array 130 is arranged at the human ear in a semicircular arrangement, and the second microphone array 160 is arranged at the human ear in a linear arrangement, wherein the microphones in the second microphone array 160 are closer to the user's ear canal than any microphone in the first microphone array 130. In some embodiments, the first microphone array 130 and the second microphone array 160 may also be arranged in a combined arrangement. For example, in FIG4B , the second microphone array 160 includes a linear arrangement portion and a semicircular arrangement portion, and the semicircular arrangement portion of the second microphone array 160 is a component of the first microphone array 130. It should be noted that the arrangement of the first microphone array 130 and the second microphone array 160 is not limited to the semicircular and linear shapes shown in FIG4A and FIG4B . The semicircular and linear shapes here are only for illustrative purposes. For the arrangement of the microphone arrays, please refer to FIG8 of this specification and its related description.

In some embodiments, the noise reduction signal can also be updated according to the manual input of the user. For example, in some embodiments, when the user wears the open-type earphones 100 to play music in a relatively noisy external environment, the user's own hearing experience is not ideal, and the user can manually adjust the parameter information of the noise reduction signal (for example, frequency information, phase information, or amplitude information) according to his or her own hearing effect. For another example, when a special user (for example, a hearing-impaired user or an older user) uses the open-type earphones 100, the hearing ability of the special user is different from that of an ordinary user, and the noise reduction wave generated by the open-type earphones 100 itself does not match the hearing ability of the special group of people, resulting in a poor hearing experience for the special user. In this case, the special user can manually adjust the frequency information, phase information or amplitude information of the noise reduction signal according to his/her own hearing effect, thereby updating the noise reduction signal to improve the hearing experience of the special user. In some embodiments, the user can manually adjust the noise reduction signal by pressing a key on the open-type earphone 100. In some embodiments, the user can also manually adjust the noise reduction signal by manually inputting the adjustment through the terminal device. In some embodiments, the open-ear headphones 100 or electronic products such as mobile phones, tablet computers, and computers that are communicatively connected to the open-ear headphones 100 can display the sound field at the user's ear canal and provide feedback to the user on the frequency information range, amplitude information range, or phase information range of the recommended noise reduction signal. The user can manually input the parameter information of the recommended noise reduction signal and then fine-tune the parameter information according to his or her own auditory experience.

In some embodiments, the signal processor 140 may estimate the noise of the first spatial position based on the picked-up ambient noise, including: performing signal separation according to the picked-up ambient noise, obtaining parameter information corresponding to the ambient noise, and generating a noise reduction signal based on the parameter information corresponding to the ambient noise. In some embodiments, the ambient noise picked up by the microphone array (e.g., the first microphone array 130, the second microphone array 160) may include noise, a user's voice, audio output by the speaker array 150, etc. In some embodiments, the audio output by the speaker array 150 may include a remote audio signal of a call, a device media audio signal, a noise reduction wave, etc. output by the speaker array 150. In some embodiments, the signal processor 140 may perform signal analysis on the environmental noise picked up by the microphone array, and perform signal separation on various sound signals included in the environmental noise to obtain multiple single sound signals such as noise, user voice, noise reduction wave, device media audio signal, remote audio signal of a call, etc. Specifically, the signal processor 140 can self-adjust the filter group parameters according to the statistical distribution characteristics and structural features of noise, user voice, noise reduction wave, device media audio, remote audio of the call, etc. in different dimensions such as space, time domain, and frequency domain, estimate the parameter information of each sound signal in the environmental noise (for example, noise, user voice, noise reduction wave, device media audio, remote audio of the call, etc.), and complete the signal separation process according to different parameter information. For example, in some embodiments, the microphone array can convert the picked-up noise, user voice, and noise reduction wave into the corresponding first signal, second signal, and third signal respectively. The signal processor 140 obtains the spatial difference (e.g., signal location), time domain difference (e.g., delay), and frequency domain difference (e.g., amplitude, phase) of the first signal, the second signal, and the third signal, and performs signal separation on the first signal, the second signal, and the third signal according to the differences in the three dimensions to obtain relatively pure first signals, second signals, and third signals. The separated first signals, second signals, and third signals correspond to pure noise, user voice, and noise reduction waves, respectively, and the signal processor 140 completes the signal separation process. In some embodiments, the signal processor 140 may update the noise reduction wave according to parameter information of the noise, noise reduction wave, device media audio, call remote audio, etc. obtained by signal separation, and the updated noise reduction wave is output through the speaker array 150.

In some embodiments, the structured features of noise may include noise distribution, noise intensity, global noise intensity, noise rate, etc., or any combination thereof. In some embodiments, noise intensity may refer to the value of a noise pixel, reflecting the noise amplitude in the noise pixel, and therefore, noise distribution may reflect the probability density of noise with different noise intensities in an image. Global noise intensity may reflect the average noise intensity or weighted average noise intensity in an image. Noise rate may reflect the degree of dispersion of noise distribution. In some embodiments, the statistical distribution characteristics of noise may include but are not limited to probability distribution density, power spectrum density, autocorrelation function, probability density function, variance, mathematical expectation, etc. In some embodiments, the user's voice, device media audio, call remote audio, etc. obtained by signal separation can also be transmitted to the call remote end. For example, when the user wears the open-type earphone 100 for a voice call, the user's voice can be transmitted to the call remote end.

FIG5 is an exemplary flow chart of estimating noise of a first spatial position according to some embodiments of the present invention. As shown in FIG5, process 500 may include:

In step 510, one or more spatial noise sources associated with the picked-up ambient noise are determined.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the spatial noise source related to the environmental noise refers to a noise source whose sound waves can be transmitted to the user's ear canal or near the user's ear canal (e.g., the first spatial position). In some embodiments, the spatial noise source may be a noise source in different directions (e.g., in front, behind, etc.) of the user's body. For example, there is crowd noise in front of the user's body and vehicle horn noise on the left side of the user's body. In this case, the spatial noise source is the crowd noise source in front of the user's body and the vehicle horn noise source on the left side of the user's body. In some embodiments, the first microphone array 130 can pick up spatial noise in all directions of the user's body, and convert the spatial noise into electrical signals and transmit them to the signal processor 140. The signal processor 140 can perform signal analysis on the electrical signals corresponding to the spatial noise to obtain parameter information (e.g., azimuth information, amplitude information, phase information, etc.) of the spatial noise in all directions. The signal processor 140 determines the spatial noise source in all directions based on the parameter information of the spatial noise in all directions, for example, the azimuth of the spatial noise source, the phase of the spatial noise source, and the amplitude of the spatial noise source. In some embodiments, the signal processor 140 can determine the spatial noise source through a noise positioning algorithm. In some embodiments, the noise positioning algorithm may include one or more of beamforming, super-resolution spatial spectrum estimation, arrival time difference, etc. In some embodiments, the signal processor 140 may divide the picked-up environmental noise into multiple sub-bands according to a specific bandwidth (for example, every 500 Hz as a frequency band), each sub-band may correspond to a different frequency range, and determine the spatial noise source corresponding to the sub-band on at least one sub-band. The specific method for positioning the spatial noise source can be found elsewhere in this specification, and will not be elaborated here. For a detailed description of determining one or more spatial noise sources related to the picked-up environmental noise, please refer to Figure 6 of this specification and its related description.

In step 520, noise at a first spatial location is estimated based on the spatial noise source.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the signal processor 140 may estimate the parameter information of the noise transmitted to the first spatial position by each spatial noise source based on the parameter information (e.g., frequency information, amplitude information, phase information, etc.) of the spatial noise sources located in various directions of the user's body obtained in step 510, thereby estimating the noise at the first spatial position. For example, in some embodiments, there is a spatial noise source in front and behind the user's body, respectively. The signal processor 140 may estimate the frequency information, phase information, or amplitude information of the front spatial noise source when the front spatial noise source is transmitted to the first spatial position based on the frequency information, phase information, or amplitude information of the front spatial noise source. The signal processor 140 estimates the frequency information, phase information or amplitude information of the rear spatial noise source when the rear spatial noise source is transmitted to the first spatial position based on the frequency information, phase information or amplitude information of the rear spatial noise source. The signal processor 140 estimates the noise information of the first spatial position based on the frequency information, phase information or amplitude information of the front spatial noise source and the frequency information, phase information or amplitude information of the rear spatial noise source, thereby estimating the noise of the first spatial position. In some embodiments, in some embodiments, the parameter information of the spatial noise source can be extracted from the frequency response curve of the spatial noise source picked up by the microphone array by a feature extraction method. In some embodiments, methods for extracting parameter information of spatial noise sources may include but are not limited to principal component analysis (PCA), independent component analysis (ICA), linear discriminant analysis (LDA), singular value decomposition (SVD), etc.

In some embodiments, determining one or more spatial noise sources related to the picked-up environmental noise may include locating one or more spatial noise sources by one or more of beamforming, super-resolution spatial spectrum estimation, or arrival time difference. The beamforming positioning method is a sound source positioning method based on controllable beamforming with maximum output power. In some embodiments, the beamforming sound source positioning method may form a beam by weighted summing of the sound signals picked up by each microphone array element in the microphone array, guiding the beam by searching for possible locations of the spatial noise source, and modifying the weights so that the output signal power of the microphone array is maximized. It should be noted that the beamforming sound source positioning method can be used in both the time domain and the frequency domain. The time shift of beamforming in the time domain is equivalent to the phase delay in the frequency domain. In some embodiments, the sound source localization method of super-resolution spatial spectrum estimation may include autoregressive AR model, minimum variance spectrum estimation (MV) and eigenvalue decomposition method (e.g., Music algorithm), etc. These methods can calculate the correlation matrix of the spatial spectrum by obtaining the sound signal of the microphone array, and effectively estimate the direction of the spatial noise source. In some embodiments, the time difference of arrival sound source localization method can first estimate the time difference of arrival, and obtain the acoustic delay (TDOA) between the array elements in the microphone array, and then use the obtained time difference of arrival to further locate the position of the spatial noise source in combination with the known spatial position of the microphone array.

In order to more clearly explain the positioning principle of the spatial noise source, the following specifically explains how the positioning of the spatial noise source is achieved by taking the beamforming sound source positioning method as an example. Taking the microphone array as a linear array as an example, the spatial noise source can be a far-field sound source, and at this time, it is considered that the incident sound waves of the spatial noise source incident on the microphone array are parallel. In the parallel sound field, when the incident angle of the incident sound wave of the spatial noise source is perpendicular to the microphone plane in the microphone array (for example, the first microphone array 130 or the second microphone array 160), the incident sound wave can reach each microphone in the microphone array (for example, the first microphone array 130 or the second microphone array 160) at the same time. In some embodiments, when the incident angle of the incident sound wave from the spatial noise source in the parallel sound field is not perpendicular to the microphone plane in the microphone array (e.g., the first microphone array 130 or the second microphone array 160), there will be a delay when the incident sound wave reaches each microphone in the microphone array (e.g., the first microphone array 130 or the second microphone array 160), and the delay can be determined by the incident angle. In some embodiments, the intensity of the superimposed noise waveform is different for different incident angles. For example, when the incident angle is 0°, the noise signal intensity is weak, and when the incident angle is 45°, the noise signal intensity is the strongest. When the incident angle is different, the superposition strength of the waveform after the noise waveform is superimposed is different, so that the microphone array has polarity, and thus the polarity diagram of the microphone array can be obtained. In some embodiments, the microphone array (for example, the first microphone array 130 or the second microphone array 160) can be a directional array, and the directivity of the directional array can be achieved through a time domain algorithm or a frequency domain phase delay algorithm, such as delay, superposition, etc. In some embodiments, by controlling different delays, directivity in different directions can be achieved. In some embodiments, the direction array is controllable and is equivalent to a spatial filter. The noise positioning area is first divided into a grid, and then each microphone is delayed in the time domain by the delay time of each grid point. Finally, the time domain delays of each microphone are added together to calculate the sound pressure of each grid, thereby obtaining the relative sound pressure of each grid, and finally realizing the spatial noise source positioning.

It should be noted that the above description of process 500 is for illustration and explanation only, and does not limit the scope of application of this specification. For those with ordinary knowledge in the relevant technical field, various modifications and changes can be made to process 500 under the guidance of this specification. For example, process 500 can also include locating the spatial noise source, extracting parameter information of the spatial noise source, etc. For another example, step 510 and step 520 can be combined into one step. However, these modifications and changes are still within the scope of this specification.

FIG. 6 is an exemplary flow chart of determining a spatial noise source according to some embodiments of the present invention. As shown in FIG. 6 , process 600 may include:

In step 610, the picked-up ambient noise is divided into a plurality of sub-bands, each sub-band corresponding to a different frequency range.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the frequencies of the ambient noise from different directions of the user's body may be different. When the signal processor 140 processes the ambient noise signal, the ambient noise frequency band may be divided into a plurality of sub-bands, each of which corresponds to a different frequency range. The frequency range corresponding to each sub-band may be a pre-set frequency range, for example, 80Hz-100Hz, 100Hz-300Hz, 300Hz-800Hz, etc. In some embodiments, each sub-band contains parameter information of the ambient noise of the corresponding frequency band. For example, the signal processor 140 may divide the picked-up environmental noise into four sub-bands of 80 Hz-100 Hz, 100 Hz-300 Hz, 300 Hz-800 Hz, and 800 Hz-1000 Hz, and these four sub-bands correspond to the parameters of the environmental noise of 80 Hz-100 Hz, 100 Hz-300 Hz, 300 Hz-800 Hz, and 800 Hz-1000 Hz, respectively.

In step 620, a spatial noise source corresponding to at least one sub-band is determined.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the signal processor 140 may perform signal analysis on the sub-bands divided by the ambient noise, obtain parameter information of the ambient noise corresponding to each sub-band, and determine the spatial noise source corresponding to each sub-band based on the parameter information. For example, in the sub-band of 300 Hz-800 Hz, the signal processor 140 may obtain parameter information (e.g., frequency information, amplitude information, phase information, etc.) of the corresponding ambient noise contained in the sub-band, and the signal processor 140 determines the spatial noise source corresponding to the sub-band of 300 Hz-800 Hz based on the obtained parameter information.

It should be noted that the above description of process 600 is for illustration and explanation only, and does not limit the scope of application of this specification. For those with ordinary knowledge in the relevant technical field, various modifications and changes can be made to process 600 under the guidance of this specification. For example, step 610 and step 620 are combined. For another example, other steps are added to process 600. However, these modifications and changes are still within the scope of this specification.

FIG. 7 is another exemplary flow chart for determining a spatial noise source according to some embodiments of the present invention. As shown in FIG. 7 , process 700 may include:

In step 710, a user head function is obtained, where the user head function reflects the reflection or absorption of sound by the user's head.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the first microphone array 130 may include a first sub-microphone array and a second sub-microphone array, and the first sub-microphone array and the second sub-microphone array are respectively located at the left ear and the right ear of the user. In some embodiments, the first microphone array 130 may be arranged in a bilateral mode, that is, a bilateral mode arrangement in which the first sub-microphone array and the second sub-microphone array are enabled at the same time. In some embodiments, when the first sub-microphone array is located at the user's left ear and the second sub-microphone array is located at the user's right ear in a bilateral arrangement, the user's head will reflect or absorb the sound signal during the transmission of the sound signal, resulting in differences in the first sub-microphone array and the second sub-microphone array picking up the same environmental noise. In some embodiments, the signal processor 140 can construct a user head function based on the difference between the parameter information of the environmental noise picked up by the first sub-microphone array and the parameter information of the same environmental noise picked up by the second sub-microphone array, and the user head function can reflect the reflection and absorption of the user's head to the sound.

In step 720, on at least one sub-band, the environmental noise picked up by the first sub-microphone array, the environmental noise picked up by the second sub-microphone array, and the user head function are combined to determine the corresponding spatial noise source.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, when the first microphone array 130 is in a bilateral mode, there is an amplitude difference and a phase difference between the amplitude information and the phase information of the ambient noise signal picked up by the first sub-microphone array and the amplitude information and the phase information of the ambient noise signal picked up by the second sub-microphone array. The signal processor 140 may perform frequency synthesis on at least one sub-band of the ambient noise according to the ambient noise picked up by the first sub-microphone array, the ambient noise picked up by the second sub-microphone array, and the user header function obtained by the signal processor 140 in step 710, that is, the frequency points of the ambient noise on the corresponding sub-band picked up by the first sub-microphone array and the frequency points of the ambient noise on the corresponding sub-band picked up by the second sub-microphone array are synthesized on at least one sub-band of the ambient noise using the header function as prior information. The parameter information contained in the sub-band after the frequency synthesis corresponds to the parameter information of the reconstructed virtual noise source. The signal processor 140 determines the spatial noise source based on the parameter information of the reconstructed virtual sound source, thereby completing the spatial noise source positioning.

In some embodiments, the first microphone array 130 may also be arranged in a unilateral mode. For example, only the first sub-microphone array or the second sub-microphone array is enabled. In some embodiments, the first microphone array 130 is arranged in a unilateral mode. When the first sub-microphone array located at the left ear of the user is enabled, the signal processor 140 may use the user's head function as prior information to synthesize the frequency points of the ambient noise on the corresponding sub-band picked up by the first sub-microphone array on at least one sub-band of the ambient noise. The parameter information contained in the sub-band after the frequency point synthesis is completed corresponds to the reconstructed virtual noise source parameter information. The signal processor 140 determines the spatial noise source based on the parameter information of the reconstructed virtual sound source, thereby completing the spatial noise source positioning.

In some embodiments, the first sub-microphone array can pick up the environmental noise reaching the left ear of the user, and the signal processor 140 can also estimate the parameter information of the environmental noise when it reaches the right ear of the user based on the environmental noise parameter information through the user head function. The signal processor 140 can more accurately complete the spatial noise source positioning based on the estimated parameter information of the environmental noise when it reaches the right ear of the user. In some embodiments, the unilateral mode of the first microphone array 130 may also be configured with only one sub-microphone array. The spatial noise source localization process in this unilateral mode is similar to the spatial noise source localization process in the unilateral mode in which only the first sub-microphone array (or the second sub-microphone array) is enabled, and will not be elaborated herein.

It should be noted that the above description of process 700 is for illustration and description only and does not limit the scope of application of this specification. For those with ordinary knowledge in the relevant technical field, various modifications and changes can be made to process 300 under the guidance of this specification. However, these modifications and changes are still within the scope of this specification.

In some embodiments, the arrangement of the first sub-microphone array or the second sub-microphone array may be an array of regular geometric shapes. FIG. 8A is a schematic diagram of the arrangement of the first sub-microphone array provided according to some embodiments of the present invention. As shown in FIG. 8A, the first sub-microphone array is a linear array. In some embodiments, the arrangement of the first sub-microphone array or the second sub-microphone array may also be an array of other shapes. For example, FIG. 8B is a schematic diagram of the arrangement of the first sub-microphone array provided according to other embodiments of the present invention. As shown in FIG. 8B, the first sub-microphone array is a cross array. For another example, FIG8C is a schematic diagram of the arrangement of the first sub-microphone array provided according to other embodiments of the present invention. As shown in FIG8C, the first sub-microphone array is a circular array. It should be noted that the arrangement of the first sub-microphone array or the second sub-microphone array is not limited to the linear array, cross array, and circular array shown in FIG8A, FIG8B, and FIG8C, and may also be array patterns of other shapes, such as a triangular array, a spiral array, a plane array, a three-dimensional array, etc., and the present invention does not limit this. It should be noted that each short solid line in FIG8A to FIG8D can be regarded as a microphone or a group of microphones. In some embodiments, when each short solid line represents a group of microphones, the number of microphones in each group may be the same or different, the type of microphones in each group may be the same or different, and the orientation of microphones in each group may be the same or different. The type, number, orientation, and spacing of the microphones may be adaptively adjusted according to actual application conditions.

In some embodiments, the arrangement of the first sub-microphone array or the second sub-microphone array may also be an array of irregular geometric shapes. For example, FIG. 8D is a schematic diagram of the arrangement of the first sub-microphone array provided according to other embodiments of the present invention. As shown in FIG. 8D, the first sub-microphone array is an irregular array. It should be noted that the irregular shape array arrangement of the first sub-microphone array or the second sub-microphone array is not limited to the shape shown in FIG. 8D, and may also be an array arrangement of irregular graphics of other shapes, such as irregular polygons, etc., which is not limited in the present invention.

In some embodiments, the microphones in the first sub-microphone array (or the second sub-microphone array) may be evenly distributed, where evenly distributed means that the distances between the microphones in the first sub-microphone array (or the second sub-microphone array) are the same. In some embodiments, the microphones in the first sub-microphone array (or the second sub-microphone array) may be unevenly distributed, where unevenly distributed means that the distances between the microphones in the first sub-microphone array (or the second sub-microphone array) are different. The distance between the microphone array elements in the sub-microphone array can be adaptively adjusted according to actual conditions, and this manual does not limit this.

FIG9A is a schematic diagram of the positional relationship between the first sub-microphone array and the second sub-microphone array provided according to some embodiments of the present invention. As shown in FIG9A , the first sub-microphone array 911 is located at the left ear of the user, and the first sub-microphone array 911 is arranged in a triangular shape. The second sub-microphone array 912 is located at the right ear of the user, and the second sub-microphone array 912 is also arranged in a triangular shape. The second sub-microphone array 912 is arranged in the same manner as the first sub-microphone array 911 and is symmetrically distributed with respect to the user's head. 9A , the extension line of the first sub-microphone array 911 along the array direction intersects with the extension line of the second sub-microphone array 912 along the array direction, and may form a quadrilateral structure.

FIG9B is a schematic diagram of the positional relationship between the first sub-microphone array and the second sub-microphone array provided according to other embodiments of the present invention. As shown in FIG9B , the first sub-microphone array 921 is located at the left ear of the user, and the first sub-microphone array 921 is arranged in a linear manner. The second sub-microphone array 922 is located at the right ear of the user, and the second sub-microphone array 922 is arranged in a triangular shape. The second sub-microphone array 922 is arranged differently from the first sub-microphone array 921 and is asymmetrically distributed with respect to the user's head. 9B , the extension line of the first sub-microphone array 921 along the array direction intersects with the extension line of the second sub-microphone array 922 along the array direction, and may form a triangular structure.

In some embodiments, the first sub-microphone array 921 and the second sub-microphone array 922 may form a quadrilateral as shown in FIG. 9A and a triangle as shown in FIG. 9B , or may form regular and/or irregular shapes such as an eight-shaped shape, a circle, an ellipse, a ring, a polygon, etc. The first sub-microphone array and the second sub-microphone array are distributed in a specific shape or a three-dimensional space, and the environmental noise of the user in all directions can be obtained in an all-round manner. The parameter information of the environmental noise obtained by each microphone can be used to more accurately locate the spatial noise source, thereby more accurately simulating the noise sound field at the user's ear canal, so as to achieve a better noise reduction effect. Different arrangements of the first sub-microphone array and the second sub-microphone array have different spatial filtering performances. As an example only, the spatial filtering performance may include the main lobe width and the side lobe (also called side lobe) width. The main lobe width refers to the maximum radiation beam of sound wave radiation. The side lobe width refers to the radiation beam other than the maximum radiation beam. Among them, the narrower the main lobe width, the higher the resolution and the better the directivity of the microphone array. The lower the side lobe height, the better the anti-interference performance of the microphone array, and the higher the side lobe height, the worse the anti-interference performance of the microphone array. For example, the main lobe width corresponding to the beam pattern of the cross array is narrower than the main lobe width corresponding to the circular, rectangular or spiral array pattern, which means that under the condition of the same number of array elements, the cross array has higher spatial resolution and better directivity. From the perspective of sidelobe height, the sidelobe width corresponding to the beam pattern of the cross array is higher than the sidelobe width corresponding to the circular, rectangular or spiral array pattern, which means that the cross array has poor anti-interference capability. The arrangement of the first sub-microphone array and the second sub-microphone array can be adaptively adjusted according to the actual application situation, and no further limitation is made here. It should be noted that each short solid line in FIG. 9A and FIG. 9B can be regarded as a microphone or a group of microphones. In some embodiments, when each short solid line is a group of microphones, the number of microphones in each group can be the same or different, the type of microphones in each group can be the same or different, and the orientation of microphones in each group can be the same or different. The type, number, orientation and spacing of the microphones can be adaptively adjusted according to the actual application. In some embodiments, a spatial super-resolution image of environmental noise can also be formed by synthetic aperture, sparse recovery, coprime array and other methods. The spatial super-resolution image can be used to reflect the signal reflection map of environmental noise to further improve the positioning accuracy of the spatial noise source. In some embodiments, the position, spacing, activation and deactivation status, etc. of the microphones in the microphone array (eg, the first microphone array 130, the second microphone array 160) may be adjusted based on the feedback of the positioning accuracy of the spatial noise source.

In some embodiments, the first microphone array 130 may include a noise microphone. The noise microphone in the first microphone array 130 is used to pick up the spatial noise in the user's ear canal. When the noise microphone picks up the spatial noise in the user's ear canal, it also picks up the noise reduction wave output by the speaker array 150. The noise reduction wave is not expected to be picked up by the noise microphone. Therefore, the noise microphone can be set at the acoustic zero point of the acoustic dipole formed in the speaker array 150 to minimize the noise reduction wave picked up by the noise microphone. In some embodiments, at least one speaker array 150 forms at least one set of acoustic dipoles, and the noise microphone is located at the acoustic zero point of the dipole radiation sound field. In some embodiments, the sound signals output by any two speakers in the speaker array 150 can be regarded as two point sound sources radiating sound outward, and the amplitude of the radiated sound is the same and the phase is opposite. The two speakers can constitute an acoustic dipole or something similar to an acoustic dipole, and the sound radiated outward has obvious directivity, forming an "8"-shaped sound radiation area. In the straight line direction where the two speakers are connected, the sound radiated from the speakers is the largest, and the sound radiated in other directions is significantly reduced, and the sound radiated from the perpendicular bisector of the two speakers is the smallest. In some embodiments, the sound signal output by a speaker in the speaker array 150 can also be regarded as a dipole. For example, a set of sound signals with approximately opposite phases and approximately the same amplitudes output from the front and back sides of the diaphragm of a speaker in the speaker array 150 can be regarded as two point sound sources.

In some embodiments, the ambient noise signal picked up by the microphone array (e.g., the first microphone array 130) at the acoustic null position may also be obtained through an algorithm. For example, in some embodiments, one or more microphones in the first microphone array 130 may be pre-set to the acoustic null position of the acoustic dipole formed by the speaker array 150 in a specific frequency band. The specific frequency band may be a frequency band that plays a key role in speech intelligibility, for example, 500 Hz-1500 Hz. In some embodiments, the signal processor 140 calculates and pre-stores compensation parameters for a specific frequency band based on the acoustic dipole position (i.e., the positions of the two loudspeakers constituting the acoustic dipole) and the acoustic transfer function. The signal processor 140 may perform amplitude compensation and/or phase compensation on the ambient noise base picked up by the remaining microphones in the first microphone array 130 (i.e., the microphones not set at the acoustic null position) according to the pre-stored compensation parameters, and the compensated ambient noise signal is equivalent to the ambient noise signal picked up by the noise microphone set at the acoustic null position. It should be noted that the microphones in the microphone array (e.g., the first microphone array 130) may not be arranged at the acoustic zero point of the acoustic dipole formed by the speaker array 150. For example, in some embodiments, the signal processor 140 may perform signal separation and extraction on the noise at the first spatial position picked up by the microphone array according to the statistical distribution and structured characteristics of different types of noise in different dimensions (e.g., spatial domain, time domain, frequency domain, etc.), thereby obtaining noise of different types (e.g., different frequencies, different phases, etc.), and eliminate the noise reduction wave emitted by the speaker array 150 picked up by the microphone array through the signal processor.

FIG. 10 is an exemplary flow chart of estimating noise of a first spatial position according to some embodiments of the present invention. As shown in FIG. 10 , process 1000 may include:

In step 1010, components associated with the signal picked up by the bone conduction microphone are removed from the picked up ambient noise to update the ambient noise.

In some embodiments, this step can be performed by the signal processor 140. In some embodiments, when the microphone array (e.g., the first microphone array 130, the second microphone array 160) picks up the environmental noise, the user's own voice will also be picked up by the microphone array, that is, the user's own voice is also regarded as part of the environmental noise. In this case, the noise reduction wave output by the speaker array 150 will cancel out the user's own voice. In some embodiments, in certain scenarios, the user's own voice needs to be retained, for example, in scenarios where the user is making a voice call, sending a voice message, etc. In some embodiments, when a user wears the open-ear headphones 100 to make a voice call or record voice information, the bone conduction microphone can pick up the sound signal of the user's speech by picking up the vibration signal generated by the facial bones or muscles of the user when speaking, and transmit it to the signal processor 140. The signal processor 140 obtains parameter information from the sound signal picked up by the bone conduction microphone, and the signal processor 140 finds and removes the sound signal component associated with the sound signal picked up by the bone conduction microphone from the environmental noise picked up by the microphone array (for example, the first microphone array 130, the second microphone array 160). The signal processor 140 updates the ambient noise according to the parameter information of the ambient noise picked up by the remaining microphone array. The updated ambient noise no longer contains the user's own voice signal, that is, the user's own voice signal is retained when the user is making a voice call.

In step 1020, the noise of the first spatial location is estimated based on the updated environmental noise.

In some embodiments, this step may be performed by the signal processor 140. In some embodiments, the signal processor 140 may estimate the noise of the first spatial position according to the updated environmental noise. For a detailed description of estimating the noise of the first spatial position according to the environmental noise, reference may be made to FIG. 2 of this specification and its related description, which will not be elaborated here.

It should be noted that the above description of process 1000 is for illustration and explanation only, and does not limit the scope of application of this specification. For those skilled in the art, various modifications and changes can be made to process 1000 under the guidance of this specification. For example, the components associated with the signal picked up by the bone conduction microphone can also be pre-processed, and the signal picked up by the bone conduction microphone can be transmitted to the terminal device as an audio signal. However, these modifications and changes are still within the scope of this specification.

In some embodiments, at least one microphone array may include a bone conduction microphone and an air conduction microphone, and the signal processor 140 may control the on/off state of the bone conduction microphone and the air conduction microphone based on the working state of the open-type earphone 100. In some embodiments, the working state of the open-type earphone 100 may refer to the use state used when the user wears the open-type earphone 100. In some embodiments, the working state of the open-type earphone 100 may include but is not limited to the music playing state, the voice call state, the voice sending state, etc. In some embodiments, when the microphone array picks up environmental noise, the on/off state of the bone conduction microphone and the on/off state of the air conduction microphone in the microphone array may be determined according to the working state of the open-type earphone 100. For example, when the user wears the open-type earphones 100 to play music, the switch state of the bone conduction microphone can be a standby state, and the switch state of the air conduction microphone can be a working state. For another example, when the user wears the open-type earphones 100 to send voice, the switch state of the bone conduction microphone can be a working state, and the switch state of the air conduction microphone can be a working state. In some embodiments, the signal processor 140 is coupled to the microphone array, and the signal processor 140 can control the switch state of the microphones in the microphone array (e.g., bone conduction microphone, air conduction microphone) by sending a control signal.

In some embodiments, the working state of the open-type earphone 100 may include a calling state and a non-calling state. In some embodiments, when the working state of the open-type earphone 100 is the non-calling state, the signal processor 140 may control the bone conduction microphone to be in a standby state. For example, when the open-type earphone 100 is in the non-calling state, the sound signal of the user's own speech may be regarded as environmental noise. In this case, the sound signal of the user's own speech included in the environmental noise picked up by the microphone array may not be filtered, so that the sound signal of the user's own speech can also be offset by the noise reduction wave output by the speaker array 150.

In some embodiments, when the open-type earphone 100 is in a call state, the signal processor 140 can control the bone conduction microphone to be in a work state. For example, when the open-type earphone 100 is in a call state, the user's own voice signal needs to be retained. In this case, the signal processor 140 can send a control signal to control the bone conduction microphone to be in a work state, and the bone conduction microphone picks up the user's voice signal. The signal processor 140 finds and removes the voice signal component associated with the voice signal picked up by the bone conduction microphone from the environmental noise picked up by the microphone array, so that the user's own voice signal does not cancel out the noise reduction wave output by the speaker array 150, thereby ensuring the user's normal call state.

In some embodiments, when the open-type earphone 100 is in a call state, if the sound pressure level of the ambient noise is greater than a preset threshold, the signal processor 140 can control the bone conduction microphone to remain in the working state. In some embodiments, the sound pressure level of the ambient noise can reflect the intensity of the ambient noise. The preset threshold here can be a value pre-stored in the open-type earphone 100, for example, 50 dB, 60 dB, or 70 dB or other arbitrary values. In some embodiments, when the sound pressure level of the ambient noise is greater than the preset threshold, the ambient noise will affect the call quality of the user. The signal processor 140 can control the bone conduction microphone to keep working by sending a control signal. The bone conduction microphone can obtain the vibration signal of the facial muscles of the user when speaking, and basically will not pick up external environmental noise. At this time, the vibration signal picked up by the bone conduction microphone is used as the voice signal during the call, thereby ensuring the user's normal call.

In some embodiments, when the open-ear headset 100 is in a call state, if the sound pressure level of the ambient noise is less than a preset threshold, the signal processor 140 can control the bone conduction microphone to switch from the working state to the standby state. In some embodiments, when the sound pressure level of the ambient noise is less than the preset threshold, the sound pressure level of the ambient noise is smaller than the sound pressure level of the sound signal generated by the user's speech. After the sound signal generated by the user's speech is partially offset by the noise reduction wave output by the speaker array 150, the remaining sound signal generated by the user's speech can still reach the call standard, which is sufficient to ensure the user's normal call. In this case, the signal processor 140 can control the bone conduction microphone to switch from the working state to the standby state by sending a control signal, thereby reducing the complexity of signal processing and the power consumption of the open-type earphone 100.

In some embodiments, the open-type earphones 100 may further include an adjustment module for adjusting the sound pressure level of the noise reduction wave. In some embodiments, the adjustment module may include a button, a voice assistant, a gesture sensor, etc. The user may adjust the noise reduction mode of the open-type earphones 100 by controlling the adjustment module. Specifically, the user may adjust (e.g., amplify or reduce) the amplitude information of the noise reduction signal by controlling the adjustment module to change the sound pressure level of the noise reduction wave emitted by the speaker array, thereby achieving different noise reduction effects. For exemplary purposes only, in some embodiments, the noise reduction mode may include a strong noise reduction mode, a medium noise reduction mode, a weak noise reduction mode, etc. For example, when the user wears the open-type headphones 100 indoors, the external environmental noise is small, and the user can turn off the noise reduction mode of the open-type headphones or adjust it to a weak noise reduction mode through the adjustment module. For another example, when the user wears the open-type headphones 100 while walking in a public place such as a street, the user needs to maintain a certain perception of the surrounding environment while listening to audio signals (e.g., music, voice information) to cope with emergencies. At this time, the user can select the intermediate noise reduction mode through the adjustment module (e.g., button or voice assistant) to retain the surrounding environmental noise (such as alarm sounds, collision sounds, car horns, etc.). For another example, when the user is riding in a means of transportation such as a subway or an airplane, the user can select the strong noise reduction mode through the adjustment module to further reduce the surrounding environmental noise. In some embodiments, the signal processor 140 may also send a prompt message to the open-ear headphones 100 or a terminal device (e.g., a mobile phone, a smart watch, etc.) that is communicatively connected to the open-ear headphones 100 based on the range of ambient noise intensity to remind the user to adjust the noise reduction mode.

The basic concepts have been described above. Obviously, for those with ordinary knowledge in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present invention. Although not explicitly stated here, those with ordinary knowledge in the art can make various modifications, improvements and amendments to the present invention. Such modifications, improvements and amendments are suggested in the present invention, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present invention.

At the same time, the present invention uses specific words to describe the embodiments of the present invention. For example, "one embodiment", "an embodiment", and/or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present invention. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different locations in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present invention can be appropriately combined.

In addition, it will be understood by those skilled in the art that various aspects of the present invention may be illustrated and described in terms of a number of patentable categories or situations, including any new and useful process, machine, product, or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present invention may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present invention may be embodied as a computer product located in one or more computer-readable media, the product including computer-readable program code.

Computer storage media may include a propagated data signal containing computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may have a variety of forms, including electromagnetic, optical, etc., or a suitable combination of forms. Computer storage media can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, device or equipment to communicate, propagate or transmit the program for use. The program code located on the computer storage medium can be transmitted through any suitable media, including radio, cable, optical cable, RF, or similar media, or any combination of the above media.

In addition, unless expressly stated in the scope of the patent application, the order of the processing elements and sequences described in the present invention, the use of numerals, letters, or other names are not used to limit the order of the processes and methods of the present invention. Although some embodiments of the invention currently considered useful are discussed through various examples in the above disclosure, it should be understood that such details are only for illustrative purposes, and the attached patent scope is not limited to the disclosed embodiments. On the contrary, the scope of the patent application is intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of the present invention. For example, although the system elements described above can be implemented through hardware devices, they can also be implemented only through software solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in order to simplify the description of the disclosure of the present invention and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the present invention, multiple features are sometimes combined into one embodiment, drawings or description thereof. However, this disclosure method does not mean that the invention object requires more features than the features mentioned in the patent application scope. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "approximately", "approximately" or "substantially" in some examples. Unless otherwise specified, "approximately", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and the scope of the patent application are approximate values, which may change according to the required features of the individual embodiments. In some embodiments, the numerical parameters should consider the specified number of significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of the scope in some embodiments of the present invention are approximate values, in specific embodiments, the settings of such numerical values are as accurate as possible within the feasible range.

Each patent, patent application, patent application disclosure, and other materials, such as articles, books, instructions, publications, documents, etc., cited in this application are hereby incorporated by reference in their entirety. Except for any application history documents that are inconsistent with or conflicting with the content of this application, and any documents that limit the broadest scope of the patent application of this invention (currently or subsequently attached to this application), it should be noted that if there is any inconsistency or conflict between the description, definition, and/or use of terminology in the attached materials of this application and the content described in this application, the description, definition, and/or use of terminology in this application shall prevail.

Finally, it should be understood that the embodiments described in the present invention are only intended to illustrate the principles of the embodiments of the present invention. Other variations may also fall within the scope of the present invention. Therefore, as an example and not a limitation, alternative configurations of the embodiments of the present invention may be considered consistent with the teachings of the present invention. Accordingly, the embodiments of the present invention are not limited to the embodiments explicitly introduced and described herein.

100: open-back headphones 110: housing structure 120: fixed structure 130: first microphone array 140: signal processor 150: speaker array 160: second microphone array 200: process 210: step 220: step 230: step 300: process 310: step 320: step 500: process 510: step 520: step 600: process 610: step 620: step 700: process 710: step 720: step 911: First sub-microphone array 912: Second sub-microphone array 921: First sub-microphone array 922: Second sub-microphone array 1000: Process 1010: Step 1020: Step

The present invention will be further described in the form of exemplary embodiments, which will be described in detail by means of drawings. These embodiments are not restrictive, and in these embodiments, the same element symbols represent the same structure, wherein:

FIG. 1 is an exemplary block diagram of an open-ear headset according to some embodiments of the present invention;

FIG. 2 is an exemplary principle flow chart of an open-ear headset according to some embodiments of the present invention;

FIG. 3 is an exemplary flow chart of updating a noise reduction signal according to some embodiments of the present invention;

FIG. 4A is an exemplary layout diagram of the arrangement and positional relationship of the first microphone array and the second microphone array provided according to some embodiments of the present invention;

FIG. 4B is an exemplary layout diagram of the arrangement of the first microphone array and the second microphone array according to other embodiments of the present invention;

FIG. 5 is an exemplary flow chart of estimating noise of a first spatial position according to some embodiments of the present disclosure;

FIG. 6 is an exemplary flow chart of determining a spatial noise source according to some embodiments of the present invention;

FIG. 7 is another exemplary flow chart for determining a spatial noise source according to some embodiments of the present invention;

FIG. 8A is a schematic diagram of the arrangement of the first sub-microphone array provided according to some embodiments of the present invention;

FIG. 8B is a schematic diagram of the arrangement of the first sub-microphone array according to other embodiments of the present invention;

FIG. 8C is a schematic diagram of the arrangement of the first sub-microphone array according to other embodiments of the present invention;

FIG. 8D is a schematic diagram of the arrangement of the first sub-microphone array according to other embodiments of the present invention;

FIG. 9A is a schematic diagram showing the positional relationship between a first sub-microphone array and a second sub-microphone array according to some embodiments of the present disclosure;

FIG. 9B is a schematic diagram showing the positional relationship between the first sub-microphone array and the second sub-microphone array according to other embodiments of the present invention;

[Figure 10] is an exemplary flowchart for estimating the noise of the first spatial position provided according to some embodiments of the present invention.

200: Process

210: Steps

220: Steps

230: Steps

Claims (10)

An open-type headset comprises: a fixing structure configured to fix the headset near the ear of a user and not to block or cover the ear canal of the user; a housing structure configured to carry: a first microphone array configured to pick up environmental noise; at least one speaker array; and a signal processor configured to: estimate noise at a first spatial position based on the picked up environmental noise, including determining one or more spatial noise sources related to the picked up environmental noise, and estimating the first spatial position based on the spatial noise sources. Noise at the first spatial position, wherein the first spatial position is closer to the user's ear canal than any microphone in the first microphone array; and a noise reduction signal is generated based on parameter information of the noise at the first spatial position, wherein the parameter information of the noise at the first spatial position includes amplitude and phase, and the noise reduction signal has the same amplitude and opposite phase to the noise at the first spatial position, so that the at least one speaker array outputs a noise reduction wave according to the noise reduction signal, and the noise reduction wave is used to eliminate the environmental noise transmitted to the user's ear canal. The open-type headphones of claim 1, wherein the housing structure is configured to accommodate a second microphone array, the second microphone array is configured to pick up the environmental noise and the noise reduction wave, the second microphone array is at least partially different from the first microphone array; and the signal processor is configured to update the noise reduction signal based on the sound signal picked up by the second microphone array. As in claim 2, the open-type headphones, wherein updating the noise reduction signal based on the sound signal picked up by the second microphone array comprises: Based on the sound signal picked up by the second microphone array, estimating the sound field at the user's ear canal; and adjusting parameter information of the noise reduction signal according to the sound field at the user's ear canal. The open-ear headphones of claim 2, wherein the second microphone array includes a microphone that is closer to the user's ear canal than any microphone in the first microphone array. As in claim 1, the open-type headphones, wherein the signal processor estimates the noise of the first spatial position based on the picked-up environmental noise, including: performing signal separation according to the picked-up environmental noise, obtaining parameter information corresponding to the environmental noise, and generating the noise reduction signal based on the parameter information. As in claim 1, the open-type headphones, wherein determining one or more spatial noise sources related to the picked-up ambient noise comprises: dividing the picked-up ambient noise into a plurality of sub-bands, each sub-band corresponding to a different frequency range; and determining the spatial noise source corresponding to at least one sub-band. As in claim 6, the open-type headphones, wherein the first microphone array includes a first sub-microphone array and a second sub-microphone array, the first sub-microphone array and the second sub-microphone array are respectively located at the left ear and the right ear of the user, and determining the spatial noise source corresponding to the at least one sub-band includes: obtaining a user head function, the user head function reflects the reflection or absorption of sound by the user's head; and on the at least one sub-band, combining the environmental noise picked up by the first sub-microphone array, the environmental noise picked up by the second sub-microphone array, and the user head function, to determine the corresponding spatial noise source. The open-ear headphones of claim 1, wherein the first microphone array includes a noise microphone, the at least one speaker array forms at least one set of acoustic dipoles, and the noise microphone is located at the acoustic zero point of the dipole radiation sound field. As in claim 1, the first microphone array includes a bone conduction microphone, the bone conduction microphone is configured to pick up the user's voice, and the signal processor estimates the noise of the first spatial position based on the picked up environmental noise, including: removing the component associated with the signal picked up by the bone conduction microphone from the picked up environmental noise to update the environmental noise; and estimating the noise of the first spatial position based on the updated environmental noise. As in claim 1, the open-type headphones, wherein the first microphone array includes a bone conduction microphone and an air conduction microphone, and the signal processor controls the switch state of the bone conduction microphone and the air conduction microphone based on the working state of the headphones.