JP2009268039A - Adjustment-free hearing aid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hearing aid that does not require adjustment at all. <P>SOLUTION: The invention relates to a hearing aid which automatically controls an amplification factor and tone quality control (TC) in accordance with an input level. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to the provision of a technique for automating sound quality adjustment (hereinafter referred to as TC) and volume control of a hearing aid.

Conventional hearing aids have volume adjustment and T.P. C. These two types of adjustments were necessary.

The hearing aid user is an elderly person with hearing loss, etc., and the fine adjustment of the device is often inadequate, and the operation of the two types of adjusters of this conventional hearing aid has been regarded as a difficulty. FIG. 1 shows an example of the external shape of a conventional hearing aid. In addition to the power switch 1, the volume adjuster 2T. C. 3 is provided.

T. automatically according to the volume. C. The Hearing Aid has an AGC (auto gain control) characteristic that can obtain an almost constant output volume regardless of the input volume. provide.

As a hearing aid for hearing-impaired people, when the input sound is small, the bass is reduced and the treble is increased. C. Is necessary, and when the input sound is loud, it becomes almost flat. C. It is necessary and there is.
This corresponds to the reduction of the bass because it is difficult to hear when the input is small, and it is amplified almost flat when the input is large.
FIG. 2 shows this hearing aid characteristic. The figure shows the relationship between the output and the frequency. When the input is small, the bass attenuation characteristic is obtained, and when the input is large, the flat characteristic is obtained.

FIG. 3 is a Fletcher-Manson curve showing human hearing characteristics, which is widely known and approved. The figure shows the relationship between the level and frequency of a sine wave. It can be seen that the sensitivity of the bass is poor when the input level is low, and is almost flat when the input is high.
The frequency characteristic of the hearing aid is automatically varied in accordance with the input in this way, and further, an AGC characteristic is added to increase the amplification level when the input is small, and the amplification level is decreased at a large input, resulting in an almost constant output. As a result, the user does not need to perform any adjustment work. The characteristics of this hearing aid are shown in FIG. The output difference between when the input is small and when the input is small is small, and when the input is small, the bass is attenuated.

FIG. 5 shows a configuration for automatically varying the amplification characteristic according to the input size as described above. The input is applied to the integrator 5. The output of the integrator 5 is detected by the diode 6, leveled by the averager 7, and returned to the other input of the integrator 5. Since the integrator 5 integrates both inputs, the output can have an AGC characteristic. Since this AGC configuration is known, details are omitted. Figure 6 shows the configuration of a hearing aid using this circuit.
In this configuration, the sound signal obtained by the microphone 8 in the figure is amplified by the amp 9, passes through the AGC circuit 10, is amplified by the amplifier 11, and is output from the earphone 12. The AGC circuit 10 may have the same configuration as that shown in FIG. FIG. 7 shows an example of AGC characteristics. The input 40 dB is compressed to 10 dB. In this state, the output level is compressed while the frequency characteristic is flat. However, when the amp 9 having the frequency characteristic as shown in FIG. 8 is used, the frequency characteristic itself as shown in FIG. As the input increases, the AGC is effective and the characteristics become flat, and the hearing aid characteristics shown in FIG. 4 are obtained. The characteristics of FIG. 8 can be realized by the circuit of FIG.

Hearing aids that use this do not require any adjustments, so of course the adjustment knob can be omitted, and an ultra-small ear hole shape is possible. Opened. It is improved from the function maladjustment (cannot make the sound you want to hear at all times) that is generally dissatisfied by hearing aid users.

In the explanation, an example of realizing with an analog circuit has been given, but naturally it can also be realized with a digital circuit.

  Example of conventional hearing aid   Frequency characteristics required by hearing aids   Fletcher characteristics   Frequency characteristics of hearing aids with AGC   AGC circuit   Hearing aid configuration   AGC characteristics   Low-frequency attenuation characteristics   Low frequency attenuation circuit

Explanation of symbols

1 Power switch 2 Volume controller 3 T. C.
4 Hearing aid body 5 Accumulator 6 Diode 7 Averaging device 8 Microphone 9 amp
10 AGC circuit 11 Power amplifier 12 Earphone

Claims (2)

Hearing aid configuration that automatically adjusts the sound quality according to the input sound signal level and makes the output level almost constant regardless of the input sound signal level 2. The hearing aid according to claim 1, wherein a bass attenuation characteristic is automatically adjusted when the input sound signal level is small, and a flat characteristic is automatically adjusted when the input sound signal level is large.

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