JPH0556499A - Digital hearing aid - Google Patents

Abstract

PURPOSE:To realize the digital hearing aid having a function able to reproduce repetitively an inputted sound and a function processing the characteristic of the inputted sound and indicating it at a low speed with respect to the hearing aid aiding the audible sense of a person having a difficulty in hearing. CONSTITUTION:This hearing aid consists of an A/D converter means 11, a digital processing means 12 consisting of a means 121 processing a sound frequency characteristic and of a means 122 outputting the sound at a different speed from that at the inputted sound, a recording means 14 and a means 15 inputting and outputting a control signal. The hearing aid is used together with a microphone 2, an earphone 3 and a controller 4 controlling the operation of the hearing aid. Thus, it is possible to compensate the audible sense of a person having a difficulty in hearing whose timewise resolution is deteriorated through the low speed reproduction of the sound whose characteristic is processed and through the repetitive reproduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hearing aid for assisting the hearing of a hearing-impaired person, and more particularly to a digital hearing aid for digital signal processing for improving clarity.

[0002]

2. Description of the Related Art As a hearing aid for assisting the hearing of a hearing-impaired person, an analog-type hearing aid which processes an amplitude and a frequency characteristic of a voice using an analog circuit has been mainly used. On the other hand, in recent years, research and development of digital hearing aids applying digital signal processing have been actively conducted. Regarding this research and development trend, for example, the Acoustical Society of Japan (19
1989 Vol. 45, No. 7, P549-P555) "Recent trends in hearing aids" and the like.

Audio signal processing in this digital hearing aid is performed by digital signal processing using a digital signal processor (hereinafter abbreviated as DSP). The processing content is described by the program. For this reason, the digital hearing aid can change the contents of voice processing by changing the program in the memory as compared with the conventional hearing aid, and the adjustment for maximizing the intelligibility of the voice for each patient is easier. You will be able to do it.

The audio signal processing used in the digital hearing aid includes processing for compensating for the deterioration of the frequency resolution, time resolution, spectral discrimination ability, sound image synthesis ability and the like of the hearing impaired person. Examples include frequency characteristic processing using a digital filter and insertion of silent intervals between consonants and vowels.
For these processes, for example, the Journal of Acoustical Society of Japan (19
1987, Vol. 43, No. 5, P 356 to P 361) “Digital hearing aid with voice feature extraction function” and the like.

Further, in the digital hearing aid, in the sense that it replaces the analog type hearing aid, it is premised that all processing is completed within a time delay that is not felt by the user.

[0006]

In the case of sensorineural hearing-impaired persons, which are common among the elderly, in order to process the voice and improve its intelligibility, it is effective to simply process the frequency characteristic of the voice. It is necessary to process the time characteristics at the same time to obtain "slow and clear" voice. However, not only in the conventional analog type hearing aid but also in the digital hearing aid, the real-time property is assumed as described above. Therefore, in addition to the processing for improving the intelligibility of the sound, a means for presenting the processed sound at a low speed is provided. Was not considered.

[0007] Further, the hearing-impaired person often understands what the other party is talking by repeatedly listening again to the other party, but the rehearing operation cannot be performed in a scene other than the one-to-one dialogue. You have been crippled. However, in conventional hearing aids, no consideration has been given to means for assisting this rehearing operation.

A first object of the present invention is to provide a digital hearing aid having a function of presenting a voice whose frequency characteristic has been processed at a lower speed than at the time of input.

A second object of the present invention is to provide a digital hearing aid having a function of repeatedly reproducing input voice.

[0010]

The first object is achieved by providing a means for recording voice in a digital hearing aid and a signal processing means for extending the time axis of a voice signal.

The above second object is achieved by providing means for recording a long voice in the digital hearing aid and means for the user to control the reproducing operation.

[0012]

In the digital hearing aid of the present invention, after the voice is recorded by the recording means, the process for extending the time axis of the voice signal is performed, so that the voice after the processing is presented to the user at a low speed. Become so.

Further, since the user can repeatedly reproduce the voice recorded by the recording means by using the means for controlling the reproduction operation, the situation where the speaker cannot hear the operation again Also in, it is possible to repeatedly listen to the voice presented immediately before.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a digital hearing aid of the present invention. The digital hearing aid 1 of the present invention comprises means 11 for performing A / D conversion and means 12 for performing digital signal processing.
And means 13 for D / A conversion and means 14 for recording
And a means 15 for inputting and outputting control signals. The means 12 for performing digital signal processing comprises means 121 for processing the frequency characteristic of voice and means 122 for outputting voice at a speed different from that at the time of input.

FIG. 2 is a detailed block diagram of an embodiment of the digital hearing aid of the present invention. A / D in this embodiment
The conversion means 11 comprises an amplifier for amplifying the microphone output and an A / D converter. The means 13 for D / A converting the similarly processed digital signal comprises a D / A converter and an amplifier for driving the earphone. The recording means 14 comprises a semiconductor data memory for holding a digitized audio signal, and the means 15 for controlling the input / output of signals from the controller 4 described below comprises an I / O circuit. Further, the means 12 for performing digital signal processing in this embodiment is a digital signal processor (DSP) whose processing contents are determined by a stored program. A microphone 2 for inputting voice, an earphone 3 for outputting voice, and a controller 4 for controlling the operation of the hearing aid are connected to the digital hearing aid 1 and used. In the program memory built in the DSP, a frequency characteristic processing program is provided as means 121 for processing the frequency characteristic of the voice, and a time axis extension of the voice is provided as means 122 for outputting the voice at a speed different from that at the time of input. There is a program to do it.

On the other hand, since the hearing characteristics of hearing-impaired persons vary greatly among individuals, the above-described voice processing program is stored in the program memory after adjusting the processing parameters according to the characteristics of each individual. FIG. 3 shows a system for performing the above parameter adjustment. The digital hearing aid 1 shown in detail in FIG. 2 is connected to a personal computer 5 through a DSP emulator 6. The DSP emulator 6 and the personal computer 5 simulate the function of the DSP incorporated in the digital hearing aid by using the characteristic adjusting program 51 on the personal computer. The parameters of the characteristic adjusting program 51 are changed, and the contents of the voice processing are adjusted so as to be the optimum processing for each user while referring to the reaction of the user. The adjusted parameters are actually stored and used in the program memory in the DSP incorporated in the digital hearing aid 1.

FIG. 4 shows a conceptual diagram of the algorithm of the time axis expansion processing. This algorithm is a process generally called time domain harmonic structure expansion or contraction or TDHS, and the overlapping lengths of 2P are multiplied by triangular weights and added together to be compressed to the length of P. 1
Sampling is done at a cycle of / 2.

FIG. 5 shows a conceptual diagram of the second algorithm of the time axis expansion / contraction processing. This algorithm is a process of detecting a silent section in the original audio signal and expanding only this silent section. These processes are different from the low speed reproduction of the tape recorder, and are processes that can present the sound at a low speed without lowering the pitch of the original sound.

On the other hand, the digital hearing aid of the present invention has two operation modes. One is the real-time mode,
In this mode, all processing is completed within a time delay that is not felt by the user. In this operating mode, A / D
Performs frequency characteristic processing such as high-frequency emphasis and formant emphasis on the converter output, and time-axis processing that does not lose real-time characteristics (for example, inserting a silent interval of several milliseconds between consonants and vowels). .. In this operation mode, the A / D converted output is always stored in the data memory. When recording continues beyond the capacity of the data memory, the address of the data memory is used periodically so that only the newest data always remains.

The other mode is a recording / playback mode in which the voice recorded in the data memory is processed. In this mode, in addition to the processing performed in the real-time mode, it is possible to perform the above-described time axis expansion processing. By using this mode, the user can perform the listening operation again. In addition, the use of the time-axis expansion processing makes it possible to reproduce the voice at a speed slower than the speed actually presented at the time of recording. Furthermore, by using the processing in the real-time mode and the time-axis expansion processing together, it becomes possible to listen to the recorded voice as a slow voice that matches the hearing characteristics of the user.

The user normally uses the digital hearing aid in real time mode. If the user wants to hear the voice given immediately before, the recording / playback mode is used. Switching between the two modes, starting and stopping the reproduction in the recording / reproducing mode, and setting the reproduction start address on the data memory are performed by a control signal from the controller. The user performs these controls through the controller according to the usage status. Regarding the setting of the reproduction address, for example, when the switch on the controller is pressed once, the reproduction starts from the voice several seconds before, and each time the switch is pressed, the reproduction is performed backward by the same time interval.

In the above description, an example in which signal processing for processing the characteristics of voice is performed using a DSP has been described. However, a circuit for performing necessary digital signal processing is realized using a digital circuit such as a gate array. However, it goes without saying that exactly the same function as the above example can be realized.

[0023]

According to the present invention, it is possible to present a voice whose frequency characteristic is processed so as to match the characteristic of each individual at a low speed, so that the hearing characteristic of a hearing-impaired person with poor time resolution is supplemented. Is possible.

Further, according to the present invention, since a voice recording function can be provided, it is possible to repeatedly reproduce the input voice later. This makes it possible to understand the information given by the voice even in a situation where the hearing-impaired person cannot perform the listening operation again.

Further, when the time axis expansion processing is performed in the recording / reproducing mode, there is a time margin corresponding to the reproduction at a low speed, so that the real-time processing is complicated in terms of the processing speed of the DSP. Processing can also be used.

[Brief description of drawings]

FIG. 1 is a block diagram of a digital hearing aid of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a digital hearing aid of the present invention.

FIG. 3 is a configuration diagram showing a system for adjusting characteristics when using an embodiment of the present invention.

FIG. 4 is a conceptual diagram of a first time-base expansion algorithm used in the embodiment of the present invention.

FIG. 5 is a conceptual diagram of a second time-base expansion algorithm used in the embodiment of the present invention.

[Explanation of symbols]

1 ... Digital hearing aid, 11 ... Means for performing A / D conversion,
12 ... Means for performing digital signal processing, 121 ... Means for processing frequency characteristics of voice, 122 ... Means for outputting voice at a speed different from that at the time of input, 13 ... Means for D / A conversion, 14 ... Recording Means, 15 ... Means for inputting / outputting control signals, 2 ... Microphone, 3 ... Earphone, 4 ... Controller, 5 ... Personal computer, 51 ... Characteristic adjusting program,
6 ... DSP emulator.

Claims (9)

[Claims] 1. A digital hearing aid for digitizing an input voice signal and processing the characteristics by digital signal processing to assist the hearing of a hearing-impaired person, a recording means for recording the input voice signal, and a recording means for recording the voice signal. The means for processing the frequency characteristic and the means for outputting the input voice at a speed different from that at the time of input without changing the pitch of the voice by using the signal read from the recording means and the time when the recorded voice is input A digital hearing aid characterized by having control means for selectively operating means for outputting at different speeds. 2. The means for outputting the recorded voice at a speed different from that at the time of input is realized by digital signal processing for expanding and contracting the harmonic structure of the input voice signal in the time domain. The described digital hearing aid. 3. The method according to claim 1, wherein the means for outputting the recorded voice at a speed different from that at the time of input is realized by digital signal processing for extending a silent section in the voice signal. Digital hearing aid. 4. The digital signal processing is performed by using a digital signal processor, the parameters required for the signal processing are adjusted according to the hearing characteristics of each user, and the means for the adjustment are: It is composed of a DSP emulator simulating the operation of a digital signal processor used in a digital hearing aid, a computer, and a digital signal processing program executed on the computer.
The digital hearing aid according to claim 2 or 3, which is realized by changing the content of the program according to the reaction of the user. 5. The recording means, after amplifying a voice signal,
The digital hearing aid according to claim 1, wherein the digital hearing aid is realized by storing a digital signal obtained by performing D / D conversion in a semiconductor memory. 6. An amplifier for amplifying a microphone output for inputting voice, and A for digitizing the amplifier output.
A / D converter, a semiconductor data memory for holding a digitized audio signal, a digital signal processor for processing the audio signal output from the A / D converter or the data signal held on the data memory, and processed. And a D / A converter for converting the digital signal into an analog signal,
The front digital signal processor has an amplifier for amplifying the output of the D / A converter and driving the earphone, and an I / O circuit for inputting and outputting a control signal from a controller for controlling the operation of the hearing aid. A digital hearing aid characterized by processing an audio signal in accordance with both a program for processing a frequency characteristic and a program for expanding a time axis of a sound or one selected by a user. 7. The processing of the audio signal by the digital signal processor includes a substantially real-time processing using the output of the A / D converter and the audio signal held on the data memory described above. 7. The digital hearing aid according to claim 6, wherein one of the processing of the signal used in the past and the one selected by the user is performed. 8. The parameters required for processing the audio signal by the digital signal processor are adjusted according to the hearing characteristics of each user, and the means for the adjustment are digital signals used in a digital hearing aid. It is composed of a DSP emulator simulating the operation of the signal processor, a computer, and a digital signal processing program executed on the computer, and is realized by changing the content of the program according to the reaction of the user. 7. A digital hearing aid according to claim 6, characterized in that 9. A reproduction start address on the memory during reproduction of the sound recorded in the semiconductor memory is set retroactively by the same time interval every time a control signal is given by the user. The digital hearing aid according to claim 5 or 6.