JP2000261894A - Hearing aid with noise suppression - Google Patents

Abstract

(57) [Problem] To provide an excellent hearing aid that suppresses noise and compensates for hearing loss aged due to aging, or compensates for hearing loss of a hearing-impaired person to facilitate hearing. SOLUTION: Left and right microphones 1 of a binaural hearing aid
The sounds input from L and 1R are added by an adder 100 to output a sum signal, and are subtracted by a subtractor 102 to output a difference signal of only noise. Noise is suppressed by the noise suppression means 103 by subtracting the spectrum of the noise from the spectrum of the sum signal in which the low-frequency component is attenuated by the filter 101, so that the left and right noises are separately suppressed. This allows
The sound coming from the front is emphasized and the noise is suppressed. Therefore, even in a noisy environment, the sound (voice) in that direction is emphasized when facing the desired direction, making it extremely easy to hear. A hearing aid effect is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for compensating for hearing loss caused by aging and for compensating for hearing loss of a hearing-impaired person.
The present invention relates to a hearing aid having a noise suppression function.

[0002]

2. Description of the Related Art A conventional hearing aid of this type uses a directional microphone to make it easy to hear a sound in a desired direction. FIG. 5 shows a configuration of a conventional example. In FIG. 5, reference numerals 1 and 11 denote omnidirectional microphones, reference numerals 2 and 22 denote AD converters for converting the outputs of the microphones 1 and 11 into digital signals, reference numeral 3 denotes signal processing means, and reference numeral 4 denotes a processing result converted into an analog signal. The DA converter 5 is an output terminal. A hearing aid is configured by amplifying an analog signal output from the output terminal 5 so that the analog signal can be heard with an earphone or the like.

[0003] The conventional example has the above configuration and operates as follows. The two omnidirectional microphones 1 and 11 are attached to an ear-hole type hearing aid or an ear-hook type hearing aid at regular intervals, and sound (sound including noise) input from the two microphones 1 and 11 is Are converted into digital signals by AD converters 2 and 22, respectively, and input to the signal processing means 5. Since the two microphones 1 and 11 are arranged at regular intervals, a sound from a certain sound source (speaker's voice) direction is detected with a relative time difference and a level difference. Signal processing means 3
Performs a process of giving the microphone a directional characteristic based on the time difference and the level difference so as to make it easier to detect a sound in a certain direction, for example, a sound (voice) ahead. Therefore,
When the direction of the noise source and the direction of the sound source (voice) are different, the voice to be heard (for example, in front) becomes easier to hear.

[0004]

In the conventional hearing aid using a directional microphone, there are a method of arranging two microphones in front and behind and a method of arranging two microphones in up and down.
In the method of arranging the microphones in front and behind, an operation is performed to determine the difference between the output of the front microphone and the output of the rear microphone in order to direct the directional characteristics forward. In this case, 1
Since two microphones are mounted on two hearing aids,
Since the arrangement interval is narrowed to about 10 to 15 mm, there is a problem that sensitivity is reduced at a low frequency. When the microphones are arranged vertically, an operation of adding outputs of the two microphones is performed in order to hear a sound ahead. In this case, the directivity becomes omnidirectional (omnidirectional) in the horizontal plane, and there is a problem that only the noise from above or below is suppressed.

The present invention solves the above-mentioned conventional problems, and provides an excellent hearing aid that suppresses noise and compensates for hearing loss aged due to aging, or compensates for hearing loss of a hearing-impaired person so that it is easy to hear. It is intended to be.

[0006]

According to the present invention, in order to solve the above-mentioned problem, sounds (sounds including noise) inputted from the left and right microphones of the binaural hearing aid are added to each other. Further, noise is suppressed using the spectrum of the signal subjected to the addition processing and the spectrum of the signal subjected to the subtraction processing. According to the method of the present invention, since the sound is picked up in a state similar to a person listening to the sound,
An acoustic signal having a natural directional characteristic can be processed. That is, the sound in the front direction arrives at both ears with the same phase and the same strength. Therefore, the sound in the front direction is emphasized in the left and right sum signals, and the sound in the front direction is canceled out in the difference signal, and only the noise remains. In general, noise has a less arriving direction than voice and has a random phase and intensity. Therefore, it can be considered that the noise included in the sum signal is substantially the same as the noise of the difference signal. Therefore, according to the method of the present invention, after matching the spectral outline of the sum signal with the spectral outline of the difference signal, it is possible to suppress noise using the spectrum of the sum signal and the spectrum of the difference signal.

Further, after matching the spectral outline of the left signal and the spectral outline of the right signal with the spectral outline of the difference signal, the noise is suppressed by using the spectrum of each signal and the spectrum of the difference signal, thereby obtaining a sound. You can reproduce the feeling of spreading.

According to the present invention, the sound (voice) arriving from the front direction is emphasized and the noise is suppressed by the above-mentioned method. Are emphasized, and an excellent hearing effect that is extremely easy to hear is obtained. Also, by suppressing the noise of each of the left and right acoustic signals individually, an excellent hearing aid effect can be obtained in which the sound (voice) in the front direction can be emphasized and heard by the binaural effect, and the sense of spaciousness can be reproduced. Things.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention collects sound from a binaural microphone of a hearing aid, adds a left signal and a right signal which are AD converted sound signals, and outputs a sum signal. And a signal processing means for performing a hearing process on the sum signal. The hearing aid with a noise suppressing function, wherein a left signal and a right signal are added to produce a sound from a frontal direction having a uniform phase and intensity. The sound (voice) is emphasized, and noise having a random phase and intensity is not emphasized, so that the sound (voice) in a relatively desired direction can be easily heard.

[0010] The invention according to claim 2 is means for collecting a sound from a binaural microphone of a hearing aid, adding a left signal and a right signal, which are A / D-converted sound signals, and outputting a sum signal; A filter that reduces the low-frequency component of, and a hearing aid with a noise suppression function that includes a signal processing unit that performs a hearing process on the output signal of the filter, so that the low-frequency component of the sum signal is attenuated. It has the effect that the loudness is reduced even in a noise environment with many low-frequency components, and the sound (speech) in the direction to be heard is more easily heard.

According to a third aspect of the present invention, there is provided means for adding a left signal and a right signal, which are sound signals that are collected from a binaural microphone of a hearing aid, and AD converted, and outputting a sum signal; Means for subtracting a signal to output a difference signal, a filter for reducing a low-frequency component of the sum signal, and means for suppressing noise using a spectrum of an output signal of the filter and a spectrum of the difference signal, A signal processing means for performing a hearing aid process on the noise-suppressed signal, the hearing aid having a noise suppression function, wherein a noise component is suppressed by referring to a spectrum of a difference signal from a spectrum of a sum signal in which a low-frequency component is attenuated. Therefore, a sound (voice) in a desired direction can be extremely easily heard even in a loud noise environment.

According to a fourth aspect of the present invention, there is provided a filter for reducing a low-frequency component of a sum signal, wherein the filter has a characteristic in which a frequency characteristic of the sum signal substantially matches a frequency characteristic of the difference signal. Item 3. A hearing aid with a noise suppression function according to Item 3, wherein the spectral outline of the sum signal matches the spectral outline of the difference signal, so that the SN ratio is significantly improved even in a noise environment with many low-frequency components. In addition, there is an effect that the noise is sufficiently suppressed even in an extremely noisy environment, and a sound (voice) in a desired direction becomes extremely easy to hear.

According to a fifth aspect of the present invention, there is provided a first and a second filter which collect sound from a binaural microphone of a hearing aid and reduce low-frequency components of a left signal and a right signal which are A / D-converted acoustic signals. Means for subtracting the acoustic signal to output a difference signal, means for suppressing noise of the left signal and right signal using the spectrum of the output signal of each filter and the spectrum of the difference signal, A hearing aid with a noise suppression function comprising signal processing means for performing hearing aid processing on the noise-suppressed signal.The noise component is referred to a difference signal spectrum from a left signal and a right signal in which low-frequency components are attenuated. Since the noise is suppressed, the sound (voice) in the desired direction can be easily heard even in a loud noise environment, and the sound can be reproduced in a spacious manner.

According to a sixth aspect of the present invention, the first and second filters for reducing the low-frequency components of the left signal and the right signal are arranged so that the frequency characteristics of the left signal and the right signal are different from each other. 6. The hearing aid with a noise suppression function according to claim 5, wherein the hearing aid has a characteristic that approximately matches the spectral outline of the left signal and the spectral outline of the right signal. The S / N ratio is extremely improved even in a noisy environment with many low-frequency components.
Even in an extremely noisy environment, the noise is sufficiently suppressed, so that the sound (voice) in the direction desired to be heard becomes extremely easy to hear, and the sound has a function of reproducing a sense of spaciousness.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of a hearing aid with a noise suppression function according to a first embodiment of the present invention. In FIG. 1, 1L is a microphone for the left ear and 1R.
Is a right ear microphone, 2L and 2R are AD converters for amplifying output signals of the respective microphones and converting them into digital signals, 100 is an adder, 3 is a signal processing means for performing hearing aid processing, and 4L and 4R are signal processing. DA converters (for left ear and right ear) for converting the result to analog signals, 5L are output terminals for left ear, and 5R are output terminals for right ear. A hearing aid is constituted by amplifying analog signals output from the output terminals 5L and 5R so that the analog signals can be received by earphones or the like.

The operation of the hearing aid with the noise suppression function configured as described above will be described. In FIG. 1, an adder 100 adds a left ear acoustic signal (left signal) and a right ear acoustic signal (right signal), and outputs a sum signal to the signal processing unit 3. The sound (sound) arriving from the front arrives at the left and right ears as sound signals having the same phase and the same intensity, so that the sound (sound) arriving from the front is emphasized by adding the left signal and the right signal. Act like so. On the other hand, it is general that noise arrives in a less clear direction than voice and has a random phase and intensity. Even if noises with random phases and intensities are added, they are not emphasized even if they are added, and only the front sound (voice) is enhanced.

The signal processing means 3 performs normal hearing aid processing on the sum signal, for example, processing such as level compression, low-frequency component adjustment, and high-frequency component adjustment. The signal processing result is converted to a DA converter 4L.
And 4R to convert the signal into an analog signal, and output a noise-suppressed acoustic signal from the output terminals 5L and 5R. In the configuration of FIG. 1, the DA converters 4L and 4R for the left ear and the right ear are used.
Are provided individually, but since the output signals are the same on the left and right, the same effect can be obtained even with a single D / A converter.

As described above, according to the first embodiment of the present invention, since the left and right acoustic signals of the binaural hearing aid are added, the desired direction (front view) This has the advantage that the sound (voice) is emphasized (the noise is relatively suppressed), and the sound is easy to hear.

(Embodiment 2) FIG. 2 is a block diagram showing the configuration of a hearing aid with a noise suppression function according to a second embodiment of the present invention. In FIG. 2, reference numeral 101 denotes a filter for attenuating low frequency components, and other components are the same as those in the first embodiment. Further, similarly to the first embodiment, the effect is the same even if the output is configured as a single system.

Embodiment 2 of the present invention is configured as described above, and the filter 101 acts so as to attenuate noise having many low-frequency components. Therefore, there is an advantage that the loudness is reduced even in a noise environment with many low-frequency components, and the sound (voice) in the desired direction is more easily heard.

(Embodiment 3) FIG. 3 is a block diagram showing a configuration of a hearing aid with a noise suppression function according to a third embodiment of the present invention. In FIG. 3, reference numeral 102 denotes a subtractor,
Reference numeral 03 denotes a noise suppressing unit, and other components are the same as those of the second embodiment. Further, as in the first and second embodiments, the effect is the same even if the output is configured as a single system.

The operation of the third embodiment configured as described above will be described. The filter 101 acts to attenuate the low-frequency component of the sum signal as in the case of the second embodiment. The subtracter 102 outputs a difference signal between the left signal and the right signal. At this time, sound (voice) coming from the front
Arrives at the left and right ears as acoustic signals of the same phase and the same strength, and thus acts to cancel the sound (voice) coming from the front by subtracting the left signal and the right signal. On the other hand, the direction of arrival of noise is less clear than voice,
In general, both the phase and the intensity are random. Therefore, even if the left signal and the right signal are subtracted, they are not canceled out, and it can be interpreted that only noise is output as a difference signal. The noise suppression unit 103 reduces only the noise component of the sum signal over the entire frequency band by, for example, subtracting the spectrum of the difference signal, that is, the spectrum of the noise from the spectrum of the sum signal in which the low-frequency component is attenuated. Other components operate in the same manner as in the first and second embodiments.

As described above, according to the third embodiment of the present invention, since the noise is suppressed by using the spectrum of the sum signal and the spectrum of the difference signal, the listening is performed even in an extremely noisy environment. There is an advantage that sound (voice) in a desired direction is extremely easy to hear.

(Embodiment 4) In Embodiment 4 of the present invention, the characteristics of the filter 101 in FIG. 3 are determined so that the spectral outline of the sum signal matches the spectral outline of the difference signal. Generally, when signals are added, the level increases as the frequency component decreases, and when the signal is subtracted, the level decreases as the frequency component decreases. The filter 101 according to the fourth embodiment operates so that the spectrum shape of the added signal substantially matches the spectrum shape of the difference signal. Therefore, the noise suppression means operates more precisely.

As described above, according to the fourth embodiment of the present invention, since the spectral outline of the sum signal matches the spectral outline of the difference signal, even in a noise environment with many low-frequency components. There is an advantage that the S / N ratio is extremely improved, and noise is sufficiently suppressed even in an extremely noisy environment, so that a sound (voice) in a desired direction becomes extremely easy to hear.

(Embodiment 5) FIG. 4 is a block diagram showing a configuration of a hearing aid with a noise suppression function according to a fifth embodiment of the present invention. In FIG. 4, 101L and 10L
Reference numeral 1R denotes first and second filters for attenuating low-frequency components of the left signal and the right signal, respectively, and the other components operate in the same manner as the configuration of FIG.

The operation of the fifth embodiment configured as described above will be described. In FIG. 4, the noise suppression unit 103 suppresses noise by a method such as subtracting the spectrum of the difference signal from the spectrum of the left signal and the spectrum of the right signal whose low-frequency components have been attenuated by the first and second filters 101L and 101R. I do. The signal processing means 3
Perform hearing aid processing on the left and right noise-suppressed signals separately,
Outputs signals for the left and right ears.

As described above, according to the fifth embodiment of the present invention, since the left signal and the right signal are separately processed, the sound (sound) in the desired direction can be heard in both ears even in a noisy environment. This has the advantage that the effect makes it extremely easy to hear and also reproduces the sense of spaciousness of the sound.

(Embodiment 6) In Embodiment 6 of the present invention, the filter 10 of FIG. 4 is designed so that the spectral outlines of the left signal and the right signal match the spectral outline of the difference signal.
Since the characteristics of 1L and 101R are determined, the noise suppression means operates more precisely. Therefore, the S / N ratio is significantly improved even in a noisy environment with many low-frequency components, the noise is sufficiently suppressed even in an extremely noisy environment, and the frontal sound (voice) is emphasized and heard by the binaural effect. Therefore, there is an advantage that the sound (voice) in the direction to be heard becomes extremely easy to hear, and a sense of spaciousness of the sound can be reproduced.

[0030]

As described above, according to the present invention, the sounds (sounds including noise) input from the left and right microphones of the binaural hearing aid are added to each other, and the spectrum of the added signal is further processed. And the spectrum of the signal subjected to the subtraction processing to suppress noise.
If the user wants to listen, the sound (voice) in that direction is emphasized, and an excellent hearing effect that is extremely easy to hear is obtained. Furthermore, the noise of each of the left and right acoustic signals is individually suppressed, and the sound (voice) in the front direction is emphasized and heard by the binaural effect,
An excellent hearing aid effect that can reproduce the sense of spaciousness of the sound can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a hearing aid with a noise suppression function according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a hearing aid with a noise suppression function according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a hearing aid with a noise suppression function according to third and fourth embodiments of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a hearing aid with a noise suppression function according to fifth and sixth embodiments of the present invention.

FIG. 5 is a block diagram showing a configuration of a hearing aid with a noise suppression function in a conventional example.

[Explanation of symbols]

 Reference Signs List 1L microphone for left ear of binaural hearing aid 1R microphone for right ear of binaural hearing aid 2L AD converter for left ear 2R AD converter for right ear 3 signal processing means 4L DA converter for left ear 4R DA for right ear Converter 5L Output terminal for left ear 5R Output terminal for right ear 100 Adder 101, 101L, 101R Filter 102 Subtractor 103 Noise suppression means

Claims (6)

[Claims] Claims 1. A sound pickup device comprising a binaural microphone of a hearing aid,
A hearing aid with a noise suppression function, comprising: means for adding a left signal and a right signal, which are A / D converted sound signals, to output a sum signal; and signal processing means for performing hearing aid processing on the sum signal. 2. A sound pickup from a binaural microphone of a hearing aid,
Means for adding the left signal and the right signal, which are A / D converted sound signals, to output a sum signal, a filter for reducing low-frequency components of the sum signal, and signal processing means for performing hearing aid processing on the output signal of the filter Hearing aid with noise suppression function. 3. Picking up sound from binaural microphones of a hearing aid,
Means for adding a left signal and a right signal, which are A / D converted sound signals, to output a sum signal, means for subtracting the sound signal to output a difference signal, and a filter for reducing a low-frequency component of the sum signal A hearing aid with a noise suppression function, comprising: means for suppressing noise using the spectrum of the output signal of the filter and the spectrum of the difference signal; and signal processing means for performing hearing aid processing on the signal whose noise has been suppressed. 4. The filter with a noise suppression function according to claim 3, wherein the filter for reducing the low-frequency component of the sum signal has characteristics in which the frequency characteristics of the sum signal substantially match the frequency characteristics of the difference signal. hearing aid. 5. The sound pickup from a binaural microphone of a hearing aid,
First and second filters for reducing the low-frequency components of the left signal and the right signal, which are the A / D-converted sound signals, means for subtracting the sound signals to output difference signals, and output signals of the filters A hearing aid having a noise suppression function, comprising: means for suppressing noise of a left signal and noise of a right signal using a spectrum and a spectrum of a difference signal; and signal processing means for performing hearing aid processing on the signal whose noise has been suppressed. 6. The first and second filters for reducing low-frequency components of a left signal and a right signal, wherein the first and second filters have characteristics in which the frequency characteristics of the left signal and the right signal substantially match the frequency characteristics of the difference signal, respectively. The hearing aid with a noise suppression function according to claim 5.