JPS6367800B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hearing aid, and more particularly to a hearing aid equipped with a noise suppressor device that is automatically selected according to the level of noise components in the environment in which the hearing aid is used.

Hearing aids can help people with hearing loss, but they improve the clarity of speech when used in quiet places, such as on the noisy street, bus, car or train. If the hearing aid is used in a car or in a noisy room, the intelligibility of the voice will deteriorate due to noise, and the hearing aid will cause discomfort.

Conventionally, there are hearing aids equipped with a noise suppressor device to solve the above problems. This noise suppressor device reduces components in bands other than the audio frequency band (low range and/or high range) among the components contained in the sound collected by the microphone, and various types are known. The effect was great. In such a conventional hearing aid, as shown in FIG. 1, the output of a preamplifier 2 connected to a microphone 1 is connected in parallel to a normal amplifier circuit 3 and a noise suppressor device 4, and Output switching switch 5
An amplifier 6, an output amplifier 7, and an earphone 8 are connected via a switch 5, and a changeover switch 5 is operated according to environmental noise conditions. In this way, in the case of the conventional type, it is necessary to operate the changeover switch 5 manually in a noisy environment, and then manually release the noise suppressor device 4 again in a quiet place, which is extremely troublesome. This operation is particularly difficult for elderly people.

Therefore, the present invention is intended to solve the above-mentioned conventional problems, and aims to provide a hearing aid that can automatically switch between using and not using a noise suppressor device.

Hereinafter, the present invention will be explained using an embodiment shown in FIG. Connect to. The wave generator 16 includes a rectifier 17,
An integrator 18 and a comparator 19 are connected in sequence,
The output from the reference voltage 20 is added to the other input of the comparator 19, and the output of the comparator 19 is connected to the amplifier circuit 13 and the noise suppressor device 14, and an electronic switch 15 for switching them.
It is connected to the. . An amplifier 21, an output amplifier 22, and an earphone 23 are sequentially connected to the output of the electronic switch 15.

The amplification circuit 13 includes a filter circuit for audibility correction, and the amplification degree may be less than 1 or more than 1. In addition, the noise suppressor device 14
As mentioned above, this is a device that reduces only the noise components that are inconvenient for audio listening.

The wave transmitter 16 has a cut-off frequency set so as to pass only the noise component, and may be a low-pass wave device, a high-pass wave device, a band-pass wave device, etc.
Selected appropriately. The rectifier 17 and the integrator 18 are
The output signal of the wave converter 16 is converted into a DC voltage according to its magnitude. This integrator 18 is a so-called smoothing circuit, and its integration constant (time constant) is set to a suitable value in consideration of the magnitude and duration of the target noise.

Next, to explain the operation, microphone 1
1 is amplified by a preamplifier 12, and part of its output is sent to an amplifier circuit 13.
is applied to the noise suppressor device 14, and one of the outputs of both is selected by the electronic switch 15. A portion of the output of the preamplifier 12 is simultaneously applied to the waveform generator 16, and the output thereof is rectified by a rectifier 17, further integrated by an integrator 18, and converted into a DC voltage. The output level of this integrator 18 is then added to one input of a comparator 19.
A predetermined voltage is applied to the other input of the comparator 19 by a reference voltage 20 in order to set the comparator 19 to operate when the desired amount of noise is present, and both inputs are compared and the result is Comparator 19
It is output from That is, when the output of the integrator 18 exceeds the voltage set by the reference voltage 20, a high level output voltage is obtained from the comparator 19, and this voltage switches the electronic switch 15 to the noise suppressor device 14 side, and the noise suppressor device You will be able to listen to the signals passed through.

On the other hand, in a quiet place without noise, integrator 1
8 has almost no output, so comparator 19
The output becomes low level. At this time, the electronic switch 15 is switched to the amplifier circuit 13 side, so that the sound can be heard without passing through the noise suppressor device. In this way, the normal amplifier circuit 13 and noise suppressor device can be automatically switched depending on the presence or absence of a noise component applied to the microphone 11 and its level.

As described above, according to the present invention, in a noisy environment that is inconvenient for hearing aids to hear conversation sounds, etc., the system automatically switches to listening through a noise suppressor device, and in order to reduce noise components, the intelligibility of hearing aids is always maintained. This allows for good listening.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional hearing aid, and FIG. 2 is a block diagram of a hearing aid according to an embodiment of the present invention. 11: Microphone, 13: Amplification circuit, 14:
Noise suppressor device, 15: Electronic switch, 1
6: wave generator, 17: rectifier, 18: integrator, 1
9: Comparator, 20: Reference voltage, 22: Output amplifier, 23: Earphone.

Claims (1)

[Claims] 1. A normal amplifier circuit and a noise suppressor device connected in parallel to the output of a microphone, and an output amplifier and earphones selectively connected to the output of either the amplifier circuit or the noise suppressor device. In the hearing aid, a wave generator, a rectifier, an integrator, a comparator to which a reference voltage is connected, and an electronic switch for switching the outputs of the amplifier circuit and the noise suppressor device are connected in parallel to the output of the microphone. A hearing aid in which the electronic switch is operated with the output of the comparator that switches according to the output level of the integrator, and the output of either the amplifier circuit or the noise suppressor device is automatically switched for listening. . 2. The hearing aid according to claim 1, wherein the integral constant of the integrator is variable.