WO2024039049A1 - Electronic device and control method therefor - Google Patents

Abstract

An electronic device is disclosed. The present electronic device comprises: a speaker; an inner microphone disposed in the direction in which the speaker emits sound; an outer microphone disposed in the direction opposite to that of the inner microphone; and a processor, which identifies a noise signal by using audio signals input through the outer microphone and inner microphone, generates an offsetting acoustic signal having the opposite wavelength of the identified noise signal by using a filter including a plurality of orthogonal basis filters, and controls the speaker such that the generated offsetting acoustic signal is output, wherein the processor identifies, on the basis of the audio signal received through the inner microphone and the audio signal received through the outer microphone, a weight value to be applied to each of the plurality of orthogonal basis filters, and generates an offsetting acoustic signal by using the plurality of orthogonal basis filters and the weight value.

Description

Electronic devices and their control methods

The present disclosure relates to an electronic device and a control method thereof, and specifically, to an electronic device capable of outputting sound that blocks external noise by adaptively changing the ANC filter value according to the sound output environment and a control method thereof. .

An audio output device is an electronic device that converts electrical signals into sound waves and outputs them. Among these sound output devices, earphones or headphones are portable. As earphones or headphones can be used not only in quiet environments but also in noisy environments, recent earphones and headphones support a noise canceling function.

Active Noise Cancellation (ANC) is a function that blocks surrounding noise by receiving surrounding sound through a microphone and outputting a sound source with the phase of the wave for the sound reversed through a speaker.

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An electronic device according to an embodiment of the present disclosure includes a speaker, an inner microphone disposed in a direction in which the speaker emits sound, an outer microphone disposed in a direction opposite to the inner microphone, and input through the outer microphone and the inner microphone. A noise signal is identified using the identified audio signal, a filter including a plurality of orthogonal basis filters is used to generate a cancellation acoustic signal having an opposite wavelength of the confirmed noise signal, and the generated cancellation acoustic signal is output. Contains a processor that controls the speaker.

In this case, the processor may check the weight value to be applied to each of the plurality of orthogonal basis filters based on the audio signal received through the inner microphone and the audio signal received through the outer microphone.

And the processor may generate the offset sound signal using the plurality of orthogonal basis filters and the weight value.

Meanwhile, the processor may determine a first transmission characteristic between the inner microphone and the outer microphone and a second transmission characteristic between the speaker and the inner microphone based on the audio signals received from each of the inner microphone and the outer microphone. there is. Additionally, the processor may calculate a plurality of weight values to be applied to the plurality of orthogonal basis filters based on the confirmed first and second transfer characteristics.

Meanwhile, each of the plurality of orthogonal basis filters may be a noise removal filter with different transfer characteristics.

Meanwhile, the plurality of orthogonal basis filters may include a plurality of IIR filters having mutual orthogonality, two FIR filters connected to each of the plurality of IIR filters, and a plurality of weight modules connected to each of the FIR filters.

Meanwhile, the plurality of orthogonal basis filters may be 8 or 16.

Meanwhile, the processor may control the speaker to output both the content sound signal corresponding to the sound source content and the calculated offset sound signal.

In this case, the processor determines a second transmission characteristic between the speaker and the inner microphone based on the audio signal received from each of the inner microphone and the outer microphone, and determines the second transmission characteristic between the speaker and the inner microphone, and determines the content based on the confirmed second transmission characteristic. The sound signal can be corrected, and the speaker can be controlled so that the corrected sound signal and the offset sound signal are output together.

In this case, the processor may perform correction only for a preset low frequency band among the content audio signals.

Meanwhile, a method of controlling an electronic device according to an embodiment of the present disclosure includes receiving an audio signal through an inner microphone disposed in a direction in which a speaker emits sound and an outer microphone disposed in a direction opposite to the inner microphone. , confirming a weight value to be applied to each of a plurality of orthogonal basis filters based on the received audio signal, generating an offset acoustic signal having an opposite wavelength of the noise signal using the plurality of orthogonal basis filters and the confirmed weight value. It includes generating and outputting the generated offset sound signal through a speaker.

In this case, the checking step includes determining a first transmission characteristic between the inner microphone and the outer microphone and a second transmission characteristic between the speaker and the inner microphone based on the audio signals received from each of the inner microphone and the outer microphone. , and a plurality of weight values to be applied to the plurality of orthogonal basis filters can be confirmed based on the confirmed first and second transfer characteristics.

Meanwhile, each of the plurality of orthogonal basis filters may be a noise removal filter with different transfer characteristics.

Meanwhile, in the output step, the content sound signal corresponding to the sound source content and the calculated offset sound signal may be output together.

Meanwhile, this control method confirms a second transmission characteristic between the speaker and the inner microphone based on the audio signal received from each of the inner microphone and the outer microphone, and determines the second transmission characteristic between the speaker and the inner microphone, and determines the content based on the confirmed second transmission characteristic. It may further include correcting the sound signal, and the outputting step may output both the corrected sound signal and the offset sound signal.

In this case, the correction step may perform correction only for a preset low frequency band among the content sound signals.

Meanwhile, in the non-transitory computer-readable storage medium on which a program for performing the control method of an electronic device of the present disclosure is recorded, the control method includes an inner microphone disposed in a direction in which a speaker emits sound, and an inner microphone disposed in a direction opposite to the inner microphone. When an audio signal is input through each of the outer microphones disposed in the direction of It includes generating a canceling acoustic signal having an opposite wavelength to the noise signal using .

The above and other aspects, features and advantages of embodiments of the present disclosure will become more apparent from the following description with reference to the accompanying drawings. In the attached drawing:

1 is a diagram illustrating an example of use of an electronic device according to an embodiment of the present disclosure;

2 is a diagram illustrating a noise removal operation according to an embodiment of the present disclosure;

3 is a diagram illustrating an example of a combination of noise removal filters according to an embodiment of the present disclosure;

4 is a diagram illustrating an example of implementation of a noise control filter according to an embodiment of the present disclosure;

5 is a diagram illustrating an example of a noise control operation according to an embodiment of the present disclosure;

6 is a diagram illustrating an example of a noise control operation according to an embodiment of the present disclosure;

7 is a diagram illustrating second transmission characteristics estimated according to an embodiment of the present disclosure;

8 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure;

9 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure, and

FIG. 10 is a flowchart illustrating a method of controlling an electronic device according to an embodiment of the present disclosure.

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Hereinafter, various embodiments will be described in more detail with reference to the attached drawings. The embodiments described herein may be modified in various ways. Specific embodiments may be depicted in the drawings and described in detail in the detailed description. However, the specific embodiments disclosed in the attached drawings are only intended to facilitate understanding of the various embodiments. Accordingly, the technical idea is not limited to the specific embodiments disclosed in the attached drawings, and should be understood to include all equivalents or substitutes included in the spirit and technical scope of the disclosure.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but these components are not limited by the above-mentioned terms. The above-mentioned terms are used only for the purpose of distinguishing one component from another.

As used herein, “includes” or “has.” Terms such as are intended to designate the presence of features, numbers, steps, operations, components, parts, or a combination thereof described in the specification, but are intended to indicate the presence of one or more other features, numbers, steps, operations, components, parts, or It should be understood that the existence or addition possibility of combinations of these is not excluded in advance. When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

And herein, “confirm.” Terms such as are intended to identify a specific target (or result), and the corresponding operation can be achieved through various methods. For example, various methods can be used to check the result through operations such as operation or calculation, or to check the result through search or comparison using a lookup table.

In this specification, the term “signal” includes not only electrical signals but also signals in the form of sound waves, and in the case of electrical signals, they may be digital signals as well as analog signals. For example, the expression audio signal (or noise signal) refers to a sound wave (or radio wave) signal if the signal is outside the electronic device, and an electrical signal if it is inside the electronic device, depending on the location. In addition, signal processing in electronic devices, which will be described later, may be not only digital signal processing, but also analog signal processing or a signal processing method using a mixture of analog and digital methods.

In this specification, the term “filter” refers to removing a specific component (for example, a specific frequency region or a specific pattern), and the filter may be a digital filter or an analog filter.

Meanwhile, a “module” or “unit” for a component used in this specification performs at least one function or operation. And, the “module” or “unit” may perform a function or operation by hardware, software, or a combination of hardware and software. Additionally, a plurality of “modules” or a plurality of “units” excluding a “module” or “unit” that must be performed on specific hardware or performed on at least one processor may be integrated into at least one module. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In the description of the present disclosure, the order of each step should be understood as non-limiting unless the preceding step must be performed logically and temporally prior to the subsequent step. In other words, except for the above exceptional cases, even if the process described as a subsequent step is performed before the process described as a preceding step, the nature of disclosure is not affected, and the scope of rights must also be defined regardless of the order of the steps. In this specification, the term “A or B” is defined not only to selectively indicate either A or B, but also to include both A and B. In addition, the term "included" in this specification has the meaning of including additional components in addition to the elements listed as included.

In this specification, only essential components necessary for description of the present disclosure are described, and components unrelated to the essence of the present disclosure are not mentioned. And it should not be interpreted in an exclusive sense that includes only the mentioned components, but in a non-exclusive sense that can also include other components.

In addition, when describing the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description thereof is abbreviated or omitted. Meanwhile, each embodiment may be implemented or operated independently, but each embodiment may be implemented or operated in combination.

1 is a diagram illustrating an example of using an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 1, the electronic device 100 is an electronic device that converts electrical signals into sound waves and outputs them. These electronic devices 100 may be earphones or headphones. Hereinafter, for ease of explanation, it is assumed that the electronic device 100 is an earphone that is inserted into the user's ear and operates. However, when implemented, the electronic device 100 may be a headphone, and content stored externally or internally. It may be a device that only performs the function of removing noise without the function of reproducing sound, a sound device that the user uses without wearing it, or a combination of an earphone and a smartphone.

When a user wears the electronic device 100 on his or her ears, the speaker of the electronic device 100 is directed toward the user's eardrums, and sound output from the electronic device 100 is transmitted toward the user's eardrums. Accordingly, the user can hear the sound.

In this way, when the electronic device 100 is worn on the ear, the electronic device 100 shields the ears, thereby supporting a certain degree of noise prevention function (or passive noise canceling). However, loud or specific external noise 10 may be transmitted to the user's eardrums, and such noise interferes with viewing content.

Accordingly, the electronic device 100 can determine the form of noise 20 transmitted to the user's eardrum, and generate and output a canceling sound signal 50 corresponding to the identified form of noise. This canceling sound signal has an opposite wavelength to the noise signal, and the two signals are destroyed by the interference of the waves.

This operation is referred to as the active noise canceling function, and as explained earlier, the type of external noise that will be transmitted to the user's eardrums must be well estimated to properly remove the noise.

*Such active noise canceling methods can be divided into feedforward (FF) ANC method and feedback (Feedback FB) ANC method depending on where the noise is collected, and what filter value is applied to the collected noise. It can be divided into a fixed filter method and an adaptive filter method.

The fixed filter method uses a fixed filter value (or filter) and has the advantage of being able to operate with low resources because it generates an offset acoustic signal with only the fixed filter value. However, when using a fixed filter value, there is a disadvantage in that it cannot adaptively respond to changes in the user's external auditory canal shape and/or wearing condition, and thus noise removal performance may vary depending on the external auditory canal shape and/or wearing condition.

On the other hand, the adaptive filter method calculates the filter value through calculation and generates an offset sound signal using the calculated filter value, so noise removal performance can be maintained even when the wearing condition changes. However, the existing adaptive filter method required a lot of resources to calculate the above-mentioned filter and the parameters that make up the filter. Therefore, it was difficult to apply the adaptive filter method to earphones with low resources.

Accordingly, the present disclosure describes a method of calculating a filter value with lower resources than before while maintaining performance regardless of the user's wearing method. First, we will first explain the method of removing noise using the feedforward method.

Figure 2 is a diagram explaining a noise removal operation according to an embodiment of the present disclosure. Specifically, FIG. 2 is a diagram illustrating a method of controlling noise using a feedforward method.

Referring to FIG. 2, the feedforward ANC model 200 includes a first response characteristic 210, a second response characteristic 230, and a filter 220.

The first response characteristic 210 represents the sound transmission characteristic between the inner microphone (d(n)) and the outer microphone (x(n)). This first response characteristic 210 may be expressed as a sound transmission characteristic between the outside of the ear and the inside of the ear (the eardrum or the space where the eardrum is located). This first response characteristic 210 has a low dependence on the sound direction, but has a high dependence on the wearing style. For example, when the electronic device 100 is worn loosely (wearing it loosely or using a large tip, etc.), more noise may enter through the gap between the tip and the ear than when it is worn tightly. In this way, the first response characteristic 210 may vary depending on the wearing condition, etc. In particular, the difference in the first response characteristic 210 occurs more in the high-bandwidth region of sound.

The second response characteristic 230 represents the sound transmission characteristic between the speaker and the inner microphone d(n). This second response characteristic 230 may also be expressed as a sound transmission characteristic between the speaker and the inside of the ear. This second response characteristic 230 also has a high dependence on the wearing style. For example, the tighter the user wears the electronic device, the better the sound from the speaker is transmitted inside the ear, and the more loosely the user wears the electronic device, the worse the transmission of sound from the speaker becomes. Its characteristics may vary depending on the In particular, the difference in the second response characteristic 230 occurs more in the low-band region of sound.

The filter 220 must have transmission characteristics to remove noise signals transmitted inside the ear. In other words, in order for the offset sound signal output from the speaker to have an opposite wavelength to the noise signal transmitted inside the ear, it must have transmission characteristics as shown in Equation 1 below.

[Equation 1]

In this way, when the filter 220 has the same transmission characteristics as Equation 1 described above, the offset sound signal output from the speaker is x(n)*F(z)*S(z) = x(n)*P( z). Therefore, if the electronic device 100 accurately determines the first response characteristic and the second response characteristic and operates with the corresponding filter value, noise cancellation is possible with high performance.

As described above, the first response characteristic 210 and the second response characteristic may change depending on the external shape, wearing condition, etc. However, if the value of the filter 220 is fixed despite changes in the first response characteristic 210 and the second response characteristic 210, the shape or size of the generated offset acoustic signal does not correspond to the noise signal, so noise cancellation performance is bound to deteriorate.

Therefore, in order to maintain performance regardless of the wearing state, an adaptive filter method that can accurately estimate the wearing state and generate an offset acoustic signal with a corresponding filter value must be used.

However, the existing adaptive filter method had many difficulties in implementation. Specifically, since a canceling sound signal must be generated and output before external noise reaches the user's eardrums, fast sampling of approximately 384 kHz is required for noise cancellation.

If the existing general method is implemented as an FIR filter, operations on approximately 32768 taps within the FIR filter are required. In other words, a system with high resources was required to calculate approximately 32768 taps at the above-mentioned sampling rate.

And even if the existing general method is implemented as an IIR filter, the divergence problem for polar position, the optimal solution is not guaranteed, and it is difficult to apply it to a system with low resources.

Accordingly, this disclosure proposes and explains a method for adaptively changing filter values even with low resources. The specific method will be described below with reference to FIG. 3.

FIG. 3 is a diagram illustrating an example of a combination of noise removal filters according to an embodiment of the present disclosure.

As described above, ANC technology is implemented from the response characteristics between the outer microphone and the inner microphone, and the response characteristics of the speaker and inner microphone states. These characteristics may change depending on the shape of the individual's ear canal and wearing conditions (e.g., size of ear tip or wearing strength, etc.).

Therefore, if the response characteristics used when implementing the ANC filter are not similar to the response characteristics when used, the ANC performance will deteriorate. In order to solve these shortcomings, we considered a method of obtaining data from various users and various wearing states and implementing the data with low resources.

Specifically, although the filter response varies depending on the wearing status of many users, the shape of each filter has very similar characteristics. Given that the similarity of the filter response shapes was confirmed, orthogonal bases that could represent all of the corresponding shapes were calculated.

Specifically, each filter value detected in various users and environments was converted into a matrix form, and a Hankel matrix for the corresponding matrix was calculated to calculate a representative orthoganl basis.

The calculated orthogonal basis is shown in Figure 3. In the illustrated example, 16 orthogonal bases are created, but in implementation, other orthogonal bases other than 16 can be used. The orthogonal basis shown in FIG. 3 has an accuracy of 95% that can implement the actual filter values identically. If higher filter accuracy is required, the number of orthogonal bases can be increased, and the filter accuracy can be increased by 95%. If it can be lowered, the number of orthogonal bases can be reduced.

Since this orthogonal basis can express the ANC filter only with the above-described orthogonal basis and the weight values to be applied to the orthogonal basis, unlike before, only a very small number (for example, 8 to 16 weight values) needs to be calculated. , calculations can be performed even with low resources.

Below, the orthogonal basis according to this embodiment and the actual filter form using it will be described.

FIG. 4 is a diagram illustrating an example of implementation of a noise control filter according to an embodiment of the present disclosure.

Referring to FIG. 4 , the filter 500 includes a plurality of IIR filters 510, a plurality of FIR filters 520, and a plurality of weight units 530. Hereinafter, the description will be made assuming that 16 orthogonal bases are used.

To apply one orthogonal basis, one biquad IIR filter, two tap FIR filters, and two weight units are required. As described above, when using 16 basis, 16 biquad IIR filters, 32 tap FIR filters, and 32 weight units are required. In the above, the value of the Biquaed IIR filter was explained in terms of one orthogonal basis, but the tap FIR filter can also be expressed as one orthogonal basis. To express these 16 orthogonal basis, 8 biquad IIR filters, 16 tap FIR filters, and 16 weight units are used.

The above-described biquad IIR filter and tap FIR filter have fixed filter values when the orthogonal basis is determined, and the weight value of the weight portion may vary depending on changes such as wearing environment.

That is, the filter 500 may generate an acoustic signal having an opposite wavelength to the noise signal based on the calculated weight value and the signal received from the outer microphone received from the external microphone.

Meanwhile, in the illustrated example, it is shown and explained that the signals received from the external outer are sequentially input to each IIR filter, but since the IIR filters (or orthogonal basis in the present disclosure) are mutually orthogonal, any one may be processed first, and in parallel It is okay to be treated as an enemy.

Below, various noise canceling models using filters according to the present disclosure will be described. First, a case in which only the feedforward method is applied will be described.

FIG. 5 is a diagram illustrating an example of a noise control operation according to an embodiment of the present disclosure.

Referring to FIG. 5, the feedforward ANC model 500 includes a first response characteristic 510, a second response characteristic 530, a filter 520, and a weight calculation unit (RLS, recursive least squares).

Since the first response characteristic 510 and the second response characteristic 530 are the same as the first response characteristic 210 and the second response characteristic 230 of FIG. 2, duplicate descriptions will be omitted.

The weight calculation unit 540 determines the weight value to be applied to each of the plurality of orthogonal basis filters based on the audio signal (d(n)) received through the inner microphone and the audio signal received through the outer microphone (x(n)). You can.

Specifically, the weight calculation unit 540 may calculate a first response characteristic based on the two received audio signals, and use the calculated response characteristic to calculate a value to be applied to each of the plurality of weights.

For example, the weight calculation unit 510 checks the value of the first response characteristic corresponding to each of the plurality of base bands, calculates a weight corresponding to the confirmed value, or calculates a weight value to be used using a pre-stored lookup table. can confirm. Alternatively, the weight calculation unit 510 may check the specific component value of the response characteristic for each of the plurality of weights and calculate the weight value corresponding to the component value, or calculate the weight value using a pre-stored lookup table. When implementing, the weight value can be confirmed by checking not the value of one component, but the value of several components or the average value of several component values.

The filter 520 may include a plurality of orthogonal basis filters as described in FIG. 4, and may generate a cancellation acoustic signal by passing the audio signal received through the outer microphone through the plurality of orthogonal basis filters. The signal that has passed through the IIR filter and the FIR filter is finally output with a weight applied to the corresponding signal, and the above-mentioned weight is optimized to a value corresponding to the first transfer characteristic and the second transfer characteristic as described above. Appropriate offset acoustic signals corresponding to the user's wearing characteristics can be generated.

Meanwhile, although the noise canceling operation using the feedforward method has been described above, it can also be applied to the feedback method when implemented, and can also be applied to the hybrid method in which feedforward and feedback are applied together. Below, an example implemented in a hybrid method will be described.

FIG. 6 is a diagram illustrating an example of a noise control operation according to an embodiment of the present disclosure.

Referring to FIG. 6, the hybrid ANC model 600 includes a first response characteristic 610, a second response characteristic 630, a filter 620, a weight calculation unit (RLS, recursive least squares) 640, and a correction module ( 650, 660).

The configurations of the first response characteristic 610, the second response characteristic 630, the filter 620, and the weight calculation unit 640 are the same as those in FIG. 5, so duplicate descriptions will be omitted.

Because the feedback FNC technology removes noise measured from the inner microphone, the low band of the sound source can be eliminated by feedback ANC. Therefore, in order to prevent low-band sound sources from being damaged, it is necessary to minimize loss of the sound source by implementing response characteristics between the speaker and the inner microphone.

This loss correction can be performed in two ways. First, in the filtering process, the filter value is modified to prevent the above-described damage in the low band. The other is to predict that the low band will be lost in the filtering and correct the sound source accordingly. The latter method is described below, but the former method can also be used when implementing. That is, the weight calculation unit 640 may calculate a weight value that takes the above-described loss into consideration when calculating the weight value.

The correction modules 650 and 660 estimate the second response characteristic and correct the content sound signal based on the estimated second response characteristic. These correction modules 650 and 660 may be composed of an estimation module 660 and a correction module 650.

Estimation module 660 may estimate the second response characteristic. Specifically, as in Equation 1, the filter may be calculated in proportion to the first response characteristic and the second response characteristic. If the filter estimates well the first response characteristic and the second response characteristic, conversely, it is also possible to calculate the second response characteristic using the first response characteristic and the characteristics of the filter.

That is, the estimation module 660 can calculate the second response characteristic using the characteristic applied to the filter 620 and the first response characteristic. The second response characteristic generated according to the present disclosure will be described later with reference to FIG. 7.

The correction module 650 may correct the content sound signal for the sound source using the estimated second response characteristic. At this time, the correction module 650 can perform correction only for the low-band region of the sound source.

FIG. 7 is a diagram illustrating second transmission characteristics estimated according to an embodiment of the present disclosure.

Referring to FIG. 7 , the second transmission characteristic is actually measured and the second transmission characteristic is estimated by the electronic device 100 according to the present disclosure described in FIG. 6 . Referring to FIG. 7, it can be seen that the estimated second transfer characteristics are very similar to the actual transfer characteristics.

In this way, since the second transmission characteristics can be well estimated, sound source loss that may occur in the feedback FNC method can be minimized.

Figure 8 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 8 , the electronic device 100 may include an inner microphone 110, an outer microphone 120, a speaker 130, and a processor 140. This electronic device 100 may be an earphone or headphone, but is not limited thereto.

The inner microphone 110 is disposed in the direction in which the speaker emits sound. Specifically, the inner microphone 110 is a microphone placed in the direction of the user's eardrum when the user wears the electronic device 100, and can collect sounds in the corresponding area and generate an audio signal.

The outer microphone 120 is disposed in a direction opposite to the inner microphone. Specifically, the outer microphone 110 is a microphone placed in the opposite direction of the user when the user wears the electronic device 100, and can generate audio signals around the user.

The inner microphone 110 and the outer microphone 120 are electronic devices that convert sound signals into electrical signals. These microphones can be implemented as dynamic microphones, condenser microphones, etc. Below, the use of two microphones is shown and explained, but when implemented, three or more microphones may be used.

The speaker 130 can output signal-processed sound. Specifically, the speaker 130 may output an offset sound signal transmitted from the processor, or may output an offset sound signal mixed with the content sound signal.

The processor 140 can control each component of the electronic device 100. For example, the processor 140 may control the outer microphone 120 and the inner microphone 110 to receive an external sound signal, and may control the speaker 130 to output a processed sound signal.

If performance of the noise canceling function is not input, the processor 140 may control the electronic device 100 to perform only a general speaker function. That is, the speaker 130 can be controlled so that an audio signal corresponding to the audio content is output.

If performance of the noise canceling function is input, the processor 140 may control the inner microphone 110 and the outer microphone 120 to receive an audio signal.

Then, the processor 140 confirms the weight value to be applied to each of the plurality of orthogonal basis filters based on the received audio signal (S1020). Specifically, the processor 140 confirms the first transmission characteristic between the inner microphone and the outer microphone and the second transmission characteristic between the speaker and the inner microphone based on the audio signals received from each of the inner microphone and the outer microphone, and confirms the confirmed A plurality of weight values to be applied to a plurality of orthogonal basis filters can be confirmed based on the first transfer characteristic and the second transfer characteristic. The method for checking the filter and weight values used in the present disclosure has been previously described, so redundant description will be omitted.

Then, the processor 140 generates an offset acoustic signal having an opposite wavelength to the noise signal using a plurality of orthogonal basis filters and the confirmed weight values (S1030).

Then, the processor 140 outputs the generated offset sound signal through the speaker (S1040). At this time, the processor 140 may output both a content sound signal corresponding to the sound source content and a calculated offset sound signal.

And when the noise canceling function is performed and sound source content is output, the processor 140 checks the second transmission characteristic between the speaker and the inner microphone based on the audio signal received from each of the inner microphone and the outer microphone, and confirms the second transmission characteristic between the speaker and the inner microphone. 2 Content sound signals can also be corrected based on transmission characteristics. Whether and the degree of correction for such sound source content may be applied differently depending on the user's settings.

As described above, the electronic device according to the present disclosure can adaptively change the noise canceling filter value by only checking the weight values to be applied to a plurality of orthogonal basis filters with different transmission characteristics, and can adapt to different external auditory canal shapes and various wearing conditions for each user. It can operate without deterioration in noise cancellation performance. In particular, the filter value can be modified only by calculating 16 weight values, which enables faster calculation (or calculation with lower resources) compared to the existing method of calculating more than 16,000 filter parameters, requiring a quick response. It can also be applied to small audio devices with relatively low resources.

FIG. 9 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 9 , the electronic device 100 may include an inner microphone 110, an outer microphone 120, a speaker 130, a processor 140, a communication device 150, and a memory 150. Since the configurations of the inner microphone 110, outer microphone 120, and speaker 130 are the same as those described in FIG. 8, detailed descriptions are omitted.

The communication device 150 communicates with an external device. For example, external devices may include AI speakers, smartphones, tablet PCs, laptop computers, wearable devices, Set-Top Box (STB), Optical Disc Drive (ODD), video players, game consoles, servers, clouds, etc. there is. The communication device 150 can transmit and receive control signals, sound signals, etc. to and from external devices. For example, the communication device 150 may include a module capable of performing communication through 3G, LTE, 5G, Wi-Fi, Bluetooth, DMB, ATSC, DVB, LAN, etc.

The communication device 150 can receive music content from an external device. At this time, the music content may be content encoded using a specific compression method, or may be decoded content. For example, when the electronic device 100 is connected to a smartphone to receive and play streaming data stored in or received from the smartphone, the communication device 150 may also receive and play the streaming data or the content itself. It can also be received as a decompressed digital signal. Additionally, when the communication device 150 is wired, that is, when the electronic device 100 is a wired earphone, it is also possible to receive an analog signal corresponding to music content.

The memory 160 stores data and algorithms that perform the functions of the electronic device 100, and may store programs and commands that run in the electronic device 100. This memory 160 may be implemented in the form of ROM, RAM, SSD, memory card, etc. Additionally, although the processor 140 and the memory 160 are shown and described as being separate, the memory 160 may be mounted on the processor 140 when implemented.

Specifically, the memory 160 may store calculation formulas or lookup tables necessary for calculating weight values. Here, the calculation formula or lookup table may be for calculating the second transfer characteristic or filter value, and it is also possible to store several pieces of information rather than a single lookup table or calculation formula. That is, the noise canceling function according to the present disclosure can support various modes. For example, a mode that removes all noise, a mode that does not remove noise of a specific frequency (e.g., other users' voices), a mode that removes only noise of a specific pattern (e.g., a car engine sound, an airplane engine sound, etc.), and the calculation formula or lookup table for each mode can be stored.

For example, if the electronic device 100 is a wireless earphone that is wirelessly connected to an external device, the processor 130 may control the communication device 150 to establish a wireless connection with another external device. When a wireless connection is established and sound source content is received from an external device, the processor 140 may control the speaker 130 to output sound corresponding to the sound source content received through the communication device 150.

Additionally, when information on whether or not the noise canceling function is applied is input from an external device, the processor 140 may perform the noise canceling function (and canceling mode) based on the input information.

Meanwhile, in the above, only the general configuration of the electronic device 100 is shown and described, but when implemented, the electronic device 100 may further include other configurations in addition to the configuration described above. For example, it may further include a sensor for detecting whether the user is wearing it, a display for displaying the operating state of the electronic device 100, and a user interface device for receiving a user's control command.

Meanwhile, in showing and explaining FIGS. 9 and 10, the electronic device 100 is assumed to be a device such as an earphone or a headphone. However, when implemented, the electronic device 100 is a device such as an earphone and a smartphone. It could be a combination. That is, a microphone and speaker are attached to the earphones, the signal is transmitted to the smartphone by wired or wireless method, the smartphone performs the noise canceling function as described above, and the resulting sound signal is output to the speaker. It can also be implemented as:

10 is a flowchart illustrating a method of controlling an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 10, an audio signal is received through an inner microphone disposed in the direction in which the speaker emits sound and an outer microphone disposed in a direction opposite to the inner microphone (S1010).

Then, the weight value to be applied to each of the plurality of orthogonal basis filters is confirmed based on the received audio signal (S1020). Specifically, based on the audio signals received from each of the inner microphone and the outer microphone, first transmission characteristics between the inner microphone and the outer microphone and second transmission characteristics between the speaker and the inner microphone are confirmed, and the confirmed first transmission characteristics and Based on the second transfer characteristic, a plurality of weight values to be applied to the plurality of orthogonal basis filters can be confirmed.

Then, a canceling acoustic signal having an opposite wavelength to the noise signal is generated using a plurality of orthogonal basis filters and the confirmed weight values (S1030).

And the generated offset sound signal is output through the speaker (S1040). At this time, the content sound signal corresponding to the sound source content and the calculated offset sound signal can be output together.

And when the noise canceling function is performed and sound source content is output, the second transmission characteristic between the speaker and the inner microphone is confirmed based on the audio signal received from each of the inner microphone and the outer microphone, and based on the confirmed second transmission characteristic Thus, the content sound signal can be corrected. Whether and the degree of correction for such sound source content may be applied differently depending on the user's settings.

As described above, the control method according to the present disclosure can adaptively change the noise canceling filter value by only checking the weight values to be applied to a plurality of orthogonal basis filters with different transmission characteristics, and can adapt to different external auditory canal shapes and various wearing conditions for each user. It can operate without deterioration in noise cancellation performance. In particular, the filter value can be modified only by calculating 16 weight values, which enables faster calculation (or calculation with lower resources) compared to the existing method of calculating more than 16,000 filter parameters, requiring a quick response. It can also be applied to small audio devices with relatively low resources.

The control method of an electronic device according to the various embodiments described above may be provided as a computer program product. A computer program product may include the S/W program itself or a non-transitory computer readable medium in which the S/W program is stored.

A non-transitory readable medium refers to a medium that stores data semi-permanently and can be read by a device, rather than a medium that stores data for a short period of time, such as registers, caches, and memories. Specifically, the various applications or programs described above may be stored and provided on non-transitory readable media such as CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM, etc.

In addition, although the preferred embodiments of the present disclosure have been shown and described above, the present disclosure is not limited to the specific embodiments described above, and the technical field to which the disclosure pertains without departing from the gist of the present disclosure as claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be understood individually from the technical ideas or perspectives of the present disclosure.

Claims (15)

In electronic devices, speaker; an inner microphone disposed in a direction in which the speaker emits sound; an outer microphone disposed in a direction opposite to the inner microphone; Confirming a noise signal using the audio signal input through the outer microphone and the inner microphone, generating a canceling acoustic signal having an opposite wavelength of the confirmed noise signal using a filter including a plurality of orthogonal basis filters, A processor that controls the speaker to output the generated offset sound signal, The processor, Confirm the weight value to be applied to each of the plurality of orthogonal basis filters based on the audio signal received through the inner microphone and the audio signal received through the outer microphone, and use the plurality of orthogonal basis filters and the weight value An electronic device that generates the canceling acoustic signal. According to paragraph 1, The processor, Confirm a first transmission characteristic between the inner microphone and the outer microphone and a second transmission characteristic between the speaker and the inner microphone based on the audio signals received from each of the inner microphone and the outer microphone, and confirm the confirmed first transmission characteristic between the speaker and the inner microphone. An electronic device that calculates a plurality of weight values to be applied to the plurality of orthogonal basis filters based on a first transfer characteristic and a second transfer characteristic. According to paragraph 1, Each of the plurality of orthogonal basis filters is, Electronic devices that are noise-cancelling filters with different transmission characteristics. According to paragraph 1, The plurality of orthogonal basis filters are: An electronic device comprising a plurality of IIR filters having mutual orthogonality, two FIR filters connected to each of the plurality of IIR filters, and a plurality of weight modules connected to each of the FIR filters. According to paragraph 1, The electronic device wherein the plurality of orthogonal basis filters are 8 or 16. According to paragraph 1, The processor, An electronic device that controls the speaker to output both a content sound signal corresponding to sound source content and the calculated offset sound signal. According to clause 6, The processor, Confirming second transmission characteristics between the speaker and the inner microphone based on audio signals received from each of the inner microphone and the outer microphone, and correcting the content sound signal based on the confirmed second transmission characteristics, An electronic device that controls the speaker so that the corrected sound signal and the offset sound signal are output together. In clause 7, The processor, An electronic device that performs correction only for a preset low frequency band among the content audio signals. In a method of controlling an electronic device, Receiving an audio signal through an inner microphone disposed in a direction in which a speaker emits sound and an outer microphone disposed in a direction opposite to the inner microphone; Confirming a weight value to be applied to each of a plurality of orthogonal basis filters based on the received audio signal; generating a canceling acoustic signal having an opposite wavelength of the noise signal using the plurality of orthogonal basis filters and the confirmed weight value; and A control method comprising: outputting the generated offset sound signal through a speaker. According to clause 9, The above confirmation steps are: Confirm a first transmission characteristic between the inner microphone and the outer microphone and a second transmission characteristic between the speaker and the inner microphone based on the audio signals received from each of the inner microphone and the outer microphone, and confirm the confirmed first transmission characteristic between the speaker and the inner microphone. A control method for confirming a plurality of weight values to be applied to the plurality of orthogonal basis filters based on a first transfer characteristic and a second transfer characteristic. According to clause 9, Each of the plurality of orthogonal basis filters is, Control method, which is a noise removal filter with different transfer characteristics. According to clause 9, The output step is, A control method for outputting a content sound signal corresponding to sound source content and the calculated offset sound signal together. According to clause 9, Confirming second transmission characteristics between the speaker and the inner microphone based on audio signals received from each of the inner microphone and the outer microphone, and correcting the content sound signal based on the confirmed second transmission characteristics. further includes ;, The output step is, A control method in which the corrected sound signal and the offset sound signal are output together. According to clause 13, The correction step is, An electronic device that performs correction only for a preset low frequency band among the content audio signals. In the non-transitory computer-readable storage medium on which a program for performing a control method of an electronic device is recorded, The control method is, When an audio signal is input through an inner microphone disposed in the direction in which a speaker emits sound and an outer microphone disposed in a direction opposite to the inner microphone, a weight value to be applied to each of a plurality of orthogonal basis filters based on the audio signal Confirming; and Generating a canceling acoustic signal having an opposite wavelength of the noise signal using the plurality of orthogonal basis filters and the confirmed weight value.

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