JPH08102991A - Sound reproduction device for handset - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a sound reproducing device for a handset that can be heard with a constant sound quality even if the way the earpiece is placed on the ear changes. [Structure] A pressure sensor 4 is attached in the vicinity of an acoustic radiation surface 6 of a receiver housing 5 to detect a contact state with a listener's ear. The control means 3 controls the frequency characteristic of the signal processing means 2 according to the value of the pressure sensor 4. Then, even if the contact state between the handset and the ear changes, the frequency characteristic of the sound heard from the ear does not change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound reproducing device for a receiver, which can be heard with a constant sound quality even when the contact state of the receiver with the ear changes.

[0002]

2. Description of the Related Art A conventional sound reproducing device for a receiver will be described with reference to the drawings. FIG. 7 is a block diagram of a conventional sound reproducing device for a handset. The voice signal output from the signal output means 1 is amplified by the amplifier 7 and received by the receiver housing 5.
It is reproduced by the speaker 8 for the handset attached to the. Here, when the receiver is placed on the ear, the speaker 8 for the receiver is provided.
The diaphragm, the ear canal, and the eardrum of the ear form a small closed space. In such a completely sealed state, the sensitivity of the receiver can be made constant below a certain frequency by appropriately setting the vibration system impedance of the speaker 8.

[0003]

However, in the above-mentioned configuration, the acoustic characteristic becomes large depending on the listening condition of the handset, for example, when the handset casing 5 is closely attached to the ear or when the handset is loosely heard. Will be different. FIG.
Shows the measured value of the sound pressure frequency characteristic when the receiver is attached to the acoustic coupler. A1 is the sealing property, A
2 is the leak characteristic when the sound leakage is small, and A3 is the leak characteristic when the sound leakage is large. As described above, the sound pressure frequency characteristic particularly in the low frequency range is different between the sealing characteristic and the leak characteristic. Therefore, the sound quality greatly changes depending on how the handset is placed on the ear, which causes a feeling of strangeness.

The present invention has been made in view of such conventional problems, and provides a sound reproducing device for a handset capable of reproducing a constant sound quality regardless of how the handset is applied to the ear. With the goal.

[0005]

According to a first aspect of the present invention, there is provided a signal output means for outputting a voice signal, a signal processing means for correcting the amplitude frequency characteristic of the voice signal output from the signal output means, and a receiver. Of at least one or more sensors that are mounted in the vicinity of the sound emission surface of the device and that detect the contact state between the receiver and the ear of the listener, and correct the amplitude-frequency characteristic of the signal processing means according to the value measured by the sensor And a control means for controlling.

According to a fifth aspect of the present invention, there is provided a signal output means for outputting a voice signal, a signal processing means for correcting the amplitude frequency characteristic of the voice signal output from the signal output means, and a sound emitting surface of the handset near the sound emitting surface. With attached microphone,
A signal comparison means for comparing a voice signal picked up by a microphone with a voice signal of the signal output means to calculate a dissimilarity, and an amplitude of the signal processing means according to the value of the dissimilarity output from the signal comparison means. And a control means for controlling the correction of the frequency characteristic.

[0007]

According to the inventions of claims 1 to 4 having such features, the degree of the leak amount of the receiver is estimated from the value of the sensor attached to the receiver housing. Then, by correcting the amplitude frequency characteristic of the low frequency band according to the degree of the leak amount, a constant sound quality is output regardless of the listening condition.

According to the inventions of claims 5 to 7 of the present application,
The dissimilarity between the signal reproduced by the speaker and the input audio signal is calculated, and the amplitude frequency characteristic in the low frequency band is corrected according to the result. In this way, a certain sound quality is reproduced regardless of the audition conditions such as how the earpiece is applied to the ear.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A receiver sound reproducing apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a sound reproducing device for a receiver according to the first embodiment. In the figure, the signal output means 1 is a circuit for outputting an audio signal, and its output is given to the signal processing means 2. The signal processing means 2 is a circuit for correcting the amplitude frequency characteristic of the audio signal, and its control signal is given by the control means 3. The control means 3 is a circuit that outputs a control signal according to the value measured by the sensor 4. The amplifier 7 is a circuit for amplifying the audio signal output from the signal processing means 2, and its output is the speaker 8.
Given to.

The speaker 8 is a speaker attached to the earpiece. A sound emitting surface 6 is provided in the earpiece so that the sound emitted from the speaker 8 enters the listener's ear. The pressure sensor 4 is attached to the outer peripheral portion of the speaker 8. The pressure sensor is a sensor that detects the contact state between the earpiece and the listener's ear, and its output is given to the control means 3. As described above, the receiver housing 5 including the receiver forms a part of the telephone.

In the present embodiment, let us consider a state in which the earpiece is placed on the ear to listen. A pressure sensor 4 mounted around the sound emitting surface 6 of the handset outputs the pressure value between the human ear and the handset. It can be estimated that the pressure value is small and the leak amount is large when the earpiece is placed lightly on the ear. On the contrary, when the earphone is strongly pressed against the ear, the pressure value becomes large and the leak amount becomes small. Then, the control means 3 gives a control signal to the signal processing means 2 based on the pressure value measured by the pressure sensor 4, and controls the frequency correction characteristic of the signal processing means 2.

FIG. 2 shows the relationship between the leak amount and the correction characteristic (No. 1) in the first embodiment. In the figure, B1 is a correction characteristic when the leak amount is large, B2 is a correction characteristic when the leak amount is intermediate, and B3 is a correction characteristic when the leak amount is small. That is, as the leak amount increases, the audio signal input from the signal output means 1 is corrected by the signal processing means 2 so as to further enhance the low frequency range. By correcting in this way, the same sound pressure frequency characteristic as in the case of the closed characteristic can be obtained regardless of the leak amount.

FIG. 3 shows the relationship between the leak amount and the correction characteristic (No. 2) in the first embodiment. In this figure, C1 is the correction characteristic when the leak amount is large, and C1 is
Reference numeral 2 is a correction characteristic when the leak amount is intermediate, and C3 is a correction characteristic when the leak amount is small. That is, as the leak amount decreases, the audio signal is corrected by the signal processing means 2 so that the low frequency range is further attenuated. By correcting in this way, the same sound pressure frequency characteristics as when the leak amount is large can be obtained regardless of the leak amount.

Although two types of correction characteristics corresponding to the leak amount are shown in FIGS. 2 and 3, the larger the number of correction characteristics, the better in order to minimize the change in sound quality. As the signal processing means 2 for correcting the amplitude frequency characteristic, an equalizer or tone control (bass / treble) by an analog circuit may be used, or an FIR or IIR type digital filter may be used. Then, the amplitude frequency characteristic of the input audio signal is corrected by the signal processing means 2, and is reproduced by the speaker 8 through the amplifier 7.

Next, a receiver sound reproducing apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram of a sound reproducing device for a receiver according to the second embodiment. In FIG. 4, the sound reproducing device for the receiver is similar to the first embodiment, and includes the signal output means 1, the signal processing means 2, the control means 3, the receiver housing 5, the sound emitting surface 6, the amplifier 7, the speaker 8, the microphone 9, and the like. The signal comparing means 10 is included. The microphone 9 is the pressure sensor 4 of the first embodiment.
It is provided on the outer peripheral portion of the speaker 8 instead of, and detects the sound pressure of the acoustic space formed by the listener's ear and the receiving section. The signal comparison means 10 is a circuit that compares the sound signal absorbed by the microphone 9 with the sound signal of the signal output means 1 and calculates the degree of dissimilarity. The calculated value here is given to the control means 3 similar to that of the first embodiment.

In the present embodiment, let us consider a state where the earpiece is placed on the earpiece to listen. The microphone 9 mounted near the sound emitting surface 6 of the handset picks up a part of the sound reproduced by the speaker 8. Then, the picked-up signal is compared with the input signal by the signal comparison means 10, and the dissimilarity is calculated. When the earpiece is lightly placed on the ear, the degree of dissimilarity increases because the low-frequency component of the sound heard by the speaker 8 is small. On the contrary, when the earpiece is strongly applied to the ear, the low-frequency component which is almost the same as the input voice signal is reproduced, and the dissimilarity becomes small. That is, when the leak amount is large, the dissimilarity is large, and when the leak amount is small, the dissimilarity is small.

The control means 3 controls the correction characteristic realized by the signal processing means 2 based on the calculated dissimilarity.
FIG. 5 shows the relationship (1) between the dissimilarity and the correction characteristic. In FIG. 5, D1 is a correction characteristic when the dissimilarity is large, D2 is a correction characteristic when the dissimilarity is intermediate,
D3 is a correction characteristic when the dissimilarity is small. That is, as the dissimilarity increases, the signal processing unit 2 corrects so as to further enhance the low frequency range. By correcting in this way, the same sound pressure frequency characteristic as in the case of the closed characteristic can be obtained regardless of the leak amount.

FIG. 6 shows the relationship (2) between the dissimilarity and the correction characteristic. In FIG. 6, E1 is a correction characteristic when the dissimilarity is large, E2 is a correction characteristic when the dissimilarity is intermediate, and E3 is a correction characteristic when the dissimilarity is small. That is, as the degree of dissimilarity decreases, the signal processing unit 2 corrects so that the low frequency range is further attenuated. By correcting in this way, the same sound pressure frequency characteristics as when the leak amount is large can be obtained regardless of the leak amount.

Although FIG. 5 and FIG. 6 show three types of correction characteristics corresponding to the dissimilarity, the larger the number of correction characteristics, the better in order to minimize the change in sound quality. As the signal processing means 2 for correcting the amplitude frequency characteristic, an equalizer or tone control (bass / treble) by an analog circuit may be used, or an FIR or IIR type digital filter may be used. The amplitude frequency characteristic of the input audio signal is corrected by the signal processing means 2 and reproduced by the speaker 8 through the amplifier 7.

[0020]

As described above, according to the first to fourth aspects of the present invention, the sensor attached to the handset casing enables
The degree of sound pressure leak in the handset is estimated, and the low-frequency amplitude-frequency characteristic is corrected according to the degree. This makes it possible to reproduce a sound with a constant sound quality regardless of the listening condition such as how the earpiece is applied to the ear, thus improving the usability of the earpiece.

According to the invention of claims 5 to 7 of the present application,
A microphone attached to the receiver casing calculates the dissimilarity between the sound pressure of the receiver and the input voice signal, and corrects the low-frequency amplitude-frequency characteristic according to the result. This makes it possible to reproduce a sound with a constant sound quality regardless of the listening conditions such as how the earpiece is applied to the ear, thus improving the usability of the earpiece.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a sound reproducing device for a handset according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram (part 1) of sound pressure vs. frequency correction of the first embodiment.

FIG. 3 is a characteristic diagram (No. 2) of sound pressure versus frequency correction according to the first embodiment.

FIG. 4 is a configuration diagram of a sound reproducing device for a handset according to a second embodiment of the present invention.

FIG. 5 is a characteristic diagram (No. 1) of sound pressure vs. frequency correction of the second embodiment.

FIG. 6 is a characteristic diagram (No. 2) of sound pressure versus frequency correction according to the second embodiment.

FIG. 7 is a block diagram of a conventional sound reproducing device for a receiver.

FIG. 8 is a characteristic diagram of sound pressure versus frequency by an acoustic coupler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 signal output means 2 signal processing means 3 control means 4 pressure sensor 5 receiver housing 6 acoustic emission surface 7 amplifier 8 speaker 9 microphone 10 signal comparison means

Claims (7)

[Claims] 1. A signal output unit for outputting a voice signal, a signal processing unit for correcting the amplitude frequency characteristic of the voice signal output from the signal output unit, and a receiver mounted near the acoustic radiation surface of the handset. At least one sensor for detecting the contact state with the listener's ear, and control means for controlling the correction of the amplitude frequency characteristic of the signal processing means according to the value measured by the sensor. A sound reproducing device for a handset, characterized in that 2. The sound reproducing device for a receiver according to claim 1, wherein the sensor is a pressure sensor for measuring a contact pressure value between the receiver and the ear of the listener. 3. The receiver according to claim 1, wherein the control unit controls the signal processing unit so as to enhance a low range of an amplitude frequency characteristic when the pressure value of the pressure sensor is small. Sound reproduction device. 4. The handset according to claim 1, wherein the control means controls the signal processing means so as to attenuate the low frequency range of the amplitude frequency characteristic when the pressure value of the pressure sensor is large. Sound reproduction device. 5. A signal output unit for outputting a voice signal, a signal processing unit for correcting the amplitude frequency characteristic of the voice signal output from the signal output unit, and a microphone mounted near the acoustic radiation surface of the handset, A signal comparing unit that compares a voice signal picked up by the microphone with a voice signal of the signal output unit and calculates a dissimilarity, and the signal according to the value of the dissimilarity output by the signal comparing unit. And a control unit for controlling correction of the amplitude frequency characteristic of the processing unit. 6. The control unit controls the signal processing unit so as to enhance a low frequency band of an amplitude frequency characteristic when the degree of dissimilarity of the signal comparison unit is large. Sound reproduction device for handsets. 7. The control means controls, when the dissimilarity of the signal comparing means is small, to attenuate a low range of the amplitude frequency characteristic of the signal processing means. Sound reproduction device for handsets.