JPH0984196A - Hearing aid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hearing aid preventing the degradation of an acoustic character istic and eliminating unpleasant feeling when a foreign matter is put in an auditory miatus by mounting a large-sized receiver on the outside of the external auditory miatus of an ear in the form of the so-called stereo headphone. SOLUTION: A headphone 1 is made so that receivers 3 may be simultaneously pushed on the both of ears 8. Two pairs of headphones 1 are connected by a connection tool 9, the headphones can are made to be mounted on the both of the ears 8 in an excellent state, the connection tool 9 is formed by the member having proper elasticity and the tool is made to come in contact with a head part 7. The receivers 3 are acoustically and loosely coupled with an auditory miatus so as not to completely close the auditory miatus and not to considerably change the acoustic nature of the auditory miatus. A circuit part 4 includes a howling prevention circuit, the circuit is mainly composed of a circuit amplifying the language voice collected by the microphone 1 and the circuit is operated because power is supplied by a switch 6 turning on/off the power source 5. The switch 6 is an automatic switch so as to turn on the power source at the time of mounting the headphone. Thus, an excellent S/N ratio is realized and the unpleasant feeling of the auditory miatus can be eliminated.

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 the hearing impaired.

[0002]

2. Description of the Related Art A conventional hearing aid has a microphone and a receiver (an electro-acoustic transducer, which is also called a speaker, which will be referred to as a receiver in the following text) integrated into a compact size, and is pushed into an ear hole (ear canal) for use. It was mainly in the form that you could not know that you were wearing a hearing aid.

[0003]

The conventional hearing aids have a tendency to sacrifice their acoustic characteristics in order to miniaturize and block the ear canal, which makes them sensitive to certain noises. For example, the sound of tapping a desk with a pencil,
In some cases, the squealing noise when handling paper was emphasized, and bass noise was generated. Therefore, there is a drawback that the background noise is larger than that when listening in an open space through a normal ear or a microphone and a speaker with good characteristics, that is, S / N is bad.

Further, it is too small to be worn, and there are drawbacks such as discomfort caused by putting a foreign substance into the ear canal. There is also a drawback that howling is likely to occur and a humming noise is generated, which is unpleasant when wearing. Also, there is a drawback that it is difficult to turn the battery on and off because the switch is small.

[0005]

Discarding the concept of downsizing, a receiver larger than a conventional hearing aid is attached to the outside of the ear canal of both ears in the form of so-called stereo headphones to reduce the size or ear canal. The sound quality is prevented from being deteriorated due to the plugging of the ear canal, and the discomfort of inserting a foreign object into the ear canal is eliminated to increase the size and improve the operability.

Therefore, according to the present invention, two sets of headphones having a microphone and a receiver are provided, and the headphones are connected by elastic connecting tools so that the headphones can be mounted near the outer sides of the ear canals of both ears. ing.

As a countermeasure against howling, it is considered that a howling prevention circuit is provided in the circuit portion and an automatic switch for automatically turning on the power when the headphones are attached is provided as a power switch.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a state in which a hearing aid of the present invention is mounted, 1 is the entire hearing aid (hereinafter referred to as headphones), 2 is a microphone, 3 is a receiver, 4 is a circuit portion such as an amplifier circuit, 5 is a power source, 6 is a switch, 7 is a human head,
8 is an ear, 9 is a connector, and two sets of headphones 1 are provided for the left and right ears.

The headphones 1 are constructed so that the receiver 3 is pressed against both ears 8 at the same time by a known method. The two sets of headphones 1 are connected by a connector 9, and the connector 9 is formed of a member having an appropriate elasticity so that it can be worn on both ears 8 in a good state, and is configured to contact the head 7. There is.

The receiver 3 completely blocks the ear canal and does not significantly change the acoustic properties of the ear canal.
Acoustically coupled to the ear canal.

As the receiver 3, the one having a wide reproduction band, which is used in a stereo headphone for ordinary music listening, can be used as it is, but since the hearing aid mainly aims to recognize a speech voice, 80
It is sufficient to be able to reproduce 00 hertz. Rather 200 ~
If the frequencies below 250 Hz are not reproduced, the intelligibility of the language tends to be improved.

Therefore, it is desirable that the lowest resonance frequency of the diaphragm of the receiver 3 is selected to be 200 to 300 hertz so that the frequency lower than it is not reproducible. The higher reproduction limit of 8000 hertz is sufficient, and in the case of Japanese, about 4000 hertz is practically acceptable.

In the headphones 1 of the present invention, 200 to 2
It is suitable to use the receiver 3 which has a reproduction range from about 50 hertz to 7,000 to 8,000 hertz.

When headphones with a wide band for listening to music are used as the receiver 3, it is necessary to improve the intelligibility of the language by setting the reproduction characteristic of the amplifier circuit as a characteristic for reproducing the above band.

The microphone 2 is constructed in the vicinity of the receiver 3 as the headphone 1 so as to be integrated with the receiver 3 and the like, and is mounted outside the ear canal. In this way, the two microphones 2 mounted near the ears produce a stereo effect similar to that of natural ears, which is very useful for understanding the location and the meaning of the language, and blocking the ear canal. There is also an advantage that it rarely changes the acoustic characteristics of the ear.

As will be described later, the circuit portion 4 is mainly composed of a circuit for amplifying a linguistic voice picked up by the microphone 1, and is operated by being turned on by a switch 6 for turning on / off the power source 5.

Since the switch 6 is large in the headphones 1 and can be made considerably larger than the switch of the conventional hearing aid, the operations such as on / off can be greatly improved.

FIG. 2 is a block diagram showing an embodiment of the circuit portion 4 of the present invention, showing a circuit configuration example including a howling prevention circuit.

Usually, when a microphone is installed near the receiver as described above, a howling phenomenon occurs when the sensitivity of the amplifier is increased. However, since the hearing aid of the present invention has a howling prevention circuit as shown in FIG. Such arrangement is possible without any problem.

In FIG. 2, reference numeral 21 denotes the circuit portion 4 of FIG. 1, which is the entire voice amplification circuit. Reference numeral 22 is a sound quality adjustment circuit, 23 is a volume adjustment circuit, 24 is an AD conversion circuit, 25 is a delay circuit, 26 is a DA conversion circuit, and 27 is a power amplification circuit.

The entire voice amplification circuit 21 is 200 to
It is an amplifier circuit for amplifying the band of 8000 Hz, and improves the clarity of the language in combination with the reproduction band of the receiver 3.

The sound quality adjusting circuit 22 changes the amplification characteristic in accordance with the personal characteristic of the ear 8, and generally speaking, the ear of a person who suffers from hearing loss has a sensitivity drop in the band of several thousand hertz. Since it is often the case, it is necessary to improve the amplification degree of the amplification circuit in this band, but this is a circuit for adjusting the amplification degree.

The volume control circuit 23 generally raises or lowers the volume according to the degree of hearing loss. The AD conversion circuit 24 cooperates with the delay circuit 25 to provide a fixed time delay between the input and the output.

The delay circuit 25 can be realized by a digital memory such as a shift register and an appropriate clock circuit, and serves as a howling prevention circuit. The delay time is selected to be around 10 ms or longer, for example. As a result, the frequency of positive feedback that can occur between the microphone 2 and the receiver 3 can be reduced to 100 hertz or less, or even to the subsonic frequency. Then, as described above, the reproduction sensitivity of the amplifier circuit or the receiver at such a frequency, or the overall sensitivity thereof is selected to be low so as to have a high-pass characteristic, so howling does not occur at this frequency.

Even if howling occurs at the natural frequency of the microphone 2 or the receiver 3 through the delay circuit 25, it takes time until the howling is established. Therefore, when a particularly large digital value is output during that time, the sound caused by it is generated. Howling can be prevented by cutting the signal before it is emitted from the receiver 3.

The effect is the same whether the delay circuit 25 is implemented by a digital circuit or an analog circuit. Generally speaking, the digital circuit has an advantage that the sound quality is less deteriorated, but the present invention may prevent howling in the delay circuit by the analog circuit.

The DA converter circuit 26 and the power amplifier circuit 27 are for converting the digital signal subjected to the predetermined signal processing into an analog signal and amplifying the signal to a level necessary for operating the receiver 3. .

Although the sound quality adjustment circuit 22 is included in the analog circuit portion in FIG. 2, it is of course possible to perform a desired sound quality adjustment using a digital filter after AD conversion.

FIG. 3 is a block diagram showing another embodiment of the circuit portion of the present invention, showing the howling prevention circuit portion.

Reference numeral 30 denotes the entire voice amplification circuit, 31 denotes an input terminal,
32 is an output end, 33 is an output end 32 from the audio amplification circuit 3
This is a circuit for feeding back a part of the output signal of 0 to the input terminal 31.

As shown in FIG. 1, the microphone 2 and the receiver 3 are integrally formed as a headphone 1, and their relative positions are fixed. Therefore, the time required for the propagation of the sound fed back from the receiver 3 to the microphone 2 is extremely short and constant. That is, the phase relationship of the sound to be fed back is fixed.

The circuit of FIG. 3 utilizes this property.
The sound fed back from the receiver 3 cancels the fed back signal by adding to the input end 31 an electric signal having substantially the same magnitude as the electric signal generated in the microphone 2 but having an opposite phase. . By interrupting the feedback loop in this way, howling is prevented.

In a high-class hearing aid, howling can be prevented by using a DSP (digital signal processor) to perform the anti-phase feedback processing on the digital signal as described above. In this case, howling can be almost completely prevented.

FIG. 4 shows an embodiment of the switch of the present invention, and shows an automatic switch for automatically turning on the power switch when the headphones 1 are attached.

Reference numeral 41 denotes a pressure receiving portion which is pushed by the ears 8 or the head 7 and moves leftward in the figure when the headphones are attached, and 42 denotes a spring which urges the pressure receiving portion 41 rightward in the figure.
3 is a permanent magnet that works with the pressure receiving portion 41, and 44 is a permanent magnet 4.
The reed switch that operates in conjunction with the movement of 3 functions as a power switch.

When the headphone is worn, the pressure receiving portion 41 is pushed by the ear 8 or the like to move leftward, and the reed switch 44 is turned on by the permanent magnet 43 interlocking with this. That is, the power is automatically turned on during use.

In this way, the power is turned on after the receiver 3 is attached to both ears, in other words, the power is turned on after the acoustic coupling between the microphone 2 and the receiver 3 is loosened, so that howling is unlikely to occur. is there.

FIG. 5 is a view showing a state in which the headphones 1 are placed away from the head. When the headphones 1 on the left side are described, the pressure receiving portion 41 receives no pressure, so that the spring 42 pushes the headphones 1 to the right in the figure. Since the permanent magnet 43 is pushed out and separated from the reed switch 44, the switch 44 is turned off, and the battery is automatically prevented from being consumed when not in use.

As another embodiment of the automatic switch, as shown in FIG. 1, when the headphone 1 is mounted, the receiver 3 is pressed against the ear 8 and the like, and an elastic connector used at that time. 9 is provided with a sensor such as a strain gauge for detecting a distortion generated when the headphone 1 is attached, and whether or not the headphones 1 are attached is detected by the output of the sensor, and the power switch is turned on / off by the automatic switch. May be configured.

Further, instead of the above-mentioned strain detecting sensor, a pressure sensor for detecting the pressure generated between the ear and the receiver when the headphone 1 is attached is provided in the hearing aid, and the output automatically turns on / off the power. The automatic switch may be configured as described above.

[0041]

As described above, since the hearing aid of the present invention is configured like headphones and the receivers are mounted near the outer sides of the ear canals of both ears, a good S / N can be realized and foreign matter can be introduced into the ear canals. It is possible to eliminate the discomfort of putting in.

Further, since the microphones are installed in the vicinity of the receivers of both ears, the hearing-impaired person can obtain the stereo effect of both ears originally possessed by humans.

Further, when the howling prevention circuit is provided, there is no discomfort due to howling, and when the automatic switch is provided, there is no concern that the battery will be consumed due to the power being on and off.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a hearing aid of the present invention is worn.

FIG. 2 is a block diagram showing an embodiment of a circuit portion of the present invention.

FIG. 3 is a block diagram showing another embodiment of the circuit portion of the present invention.

FIG. 4 is a diagram showing an embodiment of a switch of the present invention.

FIG. 5 is a diagram showing a state in which the hearing aid of the present invention is removed.

[Explanation of symbols]

 1 Headphones 2 Microphone 3 Receiver 4 Circuit part 5 Power supply 6 Switch 9 Connecting tool 25 Delay circuit 33 Feedback circuit 41 Pressure receiving part 42 Spring 43 Permanent magnet 44 Reed switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04R 5/033 H04R 5/033 Z

Claims (9)

[Claims] 1. A power source, a switch for turning the power source on and off, a microphone for collecting linguistic voice, a circuit portion including an amplifier that operates by the power source and amplifies the output of the microphone, and is connected to the circuit portion. Hearing aid, characterized in that two sets of headphones having a receiver for outputting a spoken language sound are provided, and the two sets of the headphones are connected by an elastic connecting tool so as to be mounted near the outer sides of the ear canals of both ears. . 2. The hearing aid according to claim 1, wherein a howling prevention circuit is provided in the circuit portion. 3. The hearing aid according to claim 2, wherein a delay circuit is provided as the howling prevention circuit and the total frequency characteristic of the hearing aid is set to a high pass characteristic. 4. The hearing aid according to claim 2, wherein a circuit for feeding back a part of an output signal to an input terminal is provided as the howling prevention circuit. 5. The hearing aid according to claim 2, wherein a digital signal processor is used as the howling prevention circuit, and an inverse phase feedback process is performed with the digital signal. 6. The hearing aid according to claim 1, wherein the switch is an automatic switch configured to turn on the power when the headphones are worn and turn off the power when the headphones are removed. 7. The automatic switch, wherein a pressure receiving portion that moves when the headphones are worn, a spring that biases the pressure receiving portion, a permanent magnet that interlocks with the pressure receiving portion, and an interlock with movement of the permanent magnet. 7. The hearing aid according to claim 6, wherein the hearing aid comprises a reed switch that operates in accordance with the above. 8. The automatic switch is provided in the connector, a sensor for detecting a distortion generated when headphones are attached,
The hearing aid according to claim 6, wherein the power supply is turned on / off by the output of the sensor. 9. The automatic switch is provided with a pressure sensor for detecting a pressure generated between the ear and the receiver when the headphone is worn, and the output is used to turn on / off the power supply. Hearing aid described.