JP3264636B2 - hearing aid - Google Patents

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 hearing impaired persons.

[0002]

2. Description of the Related Art A conventional hearing aid amplifies an audio signal as it is. Therefore, if the user tries to listen to the sound with a large volume, the noise also increases, and the clarity is the same. If the volume is too large, the sound is distorted and the clarity is reduced. Therefore, an attempt is made to suppress noise by removing a high sound or a low sound from the audio signal through a frequency band filter, but the influence of background noise is inevitable.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a hearing aid capable of reducing the influence of background noise to a frequency range that is easy for a listener to receive. .

[0004]

To achieve the above object, a hearing aid according to the present invention comprises a frequency band-pass filter for extracting a predetermined frequency range of an audio signal, and a predetermined frequency range extracted by the frequency band-pass filter. Waveform shaping means for forming a square wave signal from the audio signal of the above, and a gate signal generating means for generating a gate signal at a speech speed interval by integrating the square wave signal formed by the waveform shaping means. Sound reproducing means for obtaining a sound signal from a square wave signal passed only between the gate signals generated by the gate signal generating means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration explanatory view showing an embodiment of the present invention. 1 is, for example, 125 Hz to 7
A frequency band-pass filter that passes an audio signal having a frequency of 50 Hz, a waveform shaping circuit that forms a square wave signal inverted at a point crossing zero of the audio signal, and a square wave signal that differentiates the square wave signal A pulse signal generating circuit 4 for generating a pulse signal at the rise and fall of the signal is a timing control circuit, which generates a gate signal proportional to a voltage obtained by integrating the square wave signal and dividing by the elapsed time. Reference numeral 5 denotes a gate circuit that passes a pulse signal only during the period of the gate signal. 6 is a pulse demodulation circuit,
A square wave signal is formed from the pulse signal. Reference numeral 7 denotes an audio signal reproducing circuit which converts a square wave signal as a fundamental wave component into audio which is most acceptable to a listener.

That is, as for the audio signal input, the audio signal A having a frequency of, for example, 125 Hz to 750 Hz is passed by the frequency band pass filter 1 and output to the waveform shaping circuit 2.
The audio signal A that has passed through the frequency band-pass filter 1 contains noise N. The audio signal A is input from the frequency band-pass filter 1 to the waveform shaping circuit 2 and forms a square wave signal B inverted at a point where the audio signal A crosses zero to generate a pulse signal generation circuit 3 and a timing control. Output to the circuit 4. The square wave signal B output from the waveform shaping circuit 2 contains noise N. The pulse signal generating circuit 3 receives the square wave signal B from the waveform shaping circuit 2, differentiates the square wave signal B, generates a pulse signal C at the rise and fall of the square wave signal B, and generates a gate circuit 5. Output to The pulse signal C output from the pulse signal generation circuit 3 contains noise N. The square wave signal B is input from the waveform shaping circuit 2 to the timing control circuit 4, and the voltage obtained by integrating the square wave signal B and dividing by the elapsed time is a DC component of an average value.
A gate signal D proportional to this voltage is generated and output to the gate circuit 5. Usually speaking speed varies from person to person,
The gate signal D is generated from the timing control circuit 4 at the speaking speed interval of the person. The gate circuit 5 receives the pulse signal C from the pulse signal generation circuit 3 and the gate signal D from the timing control circuit 4, and the pulse signal E that passes the pulse signal C only during the gate signal D.
Is extracted, and the pulse signal E is output to the pulse demodulation circuit 6. This pulse signal E does not include noise N. The pulse signal E is input from the gate circuit 5 to the pulse demodulation circuit 6, and the pulse signal E is converted into a square wave signal F and output to the audio reproduction circuit 7. A square wave signal F is input from the pulse demodulation circuit 6 to the audio reproduction circuit 7,
The fundamental wave component of the waveform of the square wave signal F is the same as the sound fundamental wave of the sound signal input, and the square wave signal F is converted into the most acceptable sound signal G of the listener and output.

As a result, the output audio signal G is separated from the input audio signal A to obtain an audio signal G having no background noise N. Therefore, no matter how much the audio signal G is amplified, the background noise N
Will not be dominated by.

As described above, the background noise other than the average period is removed from the audio signal input to make the wavelength region optimal for the listener. Therefore, the main purpose is not to convey the speech signal itself, but to convey the spoken language. For example, conversations with music are intended primarily for conversation, and both male and female voices are considered to be the earliest audible areas for the listener.

[0009] In addition, the voice is different from person to person, even in the same word, the pitch is different, the time interval is also different, and the same word is affected by the preceding and following sounds, making speech recognition difficult. Speech recognition is facilitated by making the speech region the main purpose and the most audible to the listener.

[0010]

As described above, according to the present invention, it is possible to provide a hearing aid capable of setting a frequency range that is easy for a listener to receive and reducing the influence of background noise.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frequency band-pass filter 2 Waveform shaping circuit 3 Pulse signal generation circuit 4 Timing control circuit 5 Gate circuit 6 Pulse demodulation circuit 7 Audio signal reproduction circuit

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-344595 (JP, A) JP-A-51-11304 (JP, A) JP-A-8-294197 (JP, A) 61402 (JP, U)

Claims (1)

(57) [Claims] 1. A frequency band-pass filter for extracting a predetermined frequency region of an audio signal, waveform shaping means for forming a square wave signal from the audio signal of a predetermined frequency region extracted by the frequency band-pass filter, Integrating the square wave signal formed by the shaping means .
It is provided with a gate signal generating means for generating a gate signal, and a sound reproducing means for obtaining an audio signal from the square wave signal is passed only during the gate signal generated by the gate signal generating means at a rate intervals speaking by the Hearing aid characterized by the following.