JPH0340560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to hearing aids. Hearing aids, to put it simply, amplify sound, and are basically equipped with a microphone,
It consists of an amplifier and earphones. Some use a bone conduction receiver as a transducer instead of earphones, while others use a bone conduction receiver that contacts the stirrup bone, as is the case with implantable middle ear and cochlear implants, which have been attracting attention recently. Some devices use a vibrator, or a needle electrode inserted into the cochlea; all of these are collectively referred to as hearing aids.

[Background technology and its problems]

Although hearing aids are said to amplify sound, they also have various additional functions and process sound signals in various ways. By the way, in conventional hearing aids, among the factors that make up sound, attention is paid to frequency and level, and these are processed. For example, in terms of frequency characteristics, high-pitched sounds are amplified in particular, and an output limiting device is installed to prevent the sound level from exceeding the discomfort threshold, making adjustments as appropriate to suit the hearing ability of the hearing-impaired.

Now, people with hearing loss usually have a narrower dynamic range of hearing than people with normal hearing, although this varies depending on the degree of disability. In this case, the dynamic cleanse is usually
This is the value obtained by subtracting the minimum audible threshold (hereinafter referred to as HTL) from the discomfort threshold (hereinafter referred to as UCL).
UCL refers to the intensity at which a sound cannot be heard, and HTL refers to the minimum level at which a sound can be heard. UCL is 100~ for people with normal hearing.
110dBHL (measured with an audiometer), and for people with hearing loss, it is roughly distributed between 110 and 120dBHL. Therefore, the auditory dynamic range for a moderately hearing-impaired person with an HTL of 70 dBHL is 120 dB - 70 dB =
This is 50 dB, and if you use an ordinary hearing aid and adjust it so that the audio information falls within the dynamic range, you will be able to fully understand conversations. However, for people with severe hearing loss whose HTL is 110 dBHL to 120 dBHL, the dynamic range of hearing is 120 dB - 100 dB (or 110 dB) = 20 dB.
(10 dB), making it impossible to understand all speech sounds even if the level is amplified with a hearing aid. In other words, for vowels, the difference between the effective value level and the peak factor is 15 dB to 20 dB, so most of the time you only hear the peak factor part, and for consonants, the energy is about 15 dB compared to vowels. Syllable intelligibility is quite poor due to the low ~30 dB. Furthermore, if the level of conversational sounds becomes even slightly lower, the amount of audio information above HTL will decrease by that amount, further worsening syllable intelligibility.

As mentioned above, conventional hearing aids have not been able to adequately respond to the poor hearing caused by the narrow dynamic range of people with hearing loss, especially those with severe hearing loss.

[Purpose of the invention]

The present invention changes the conventional way of hearing aids, which solves hearing problems using sound level information. In other words, by converting the audio wave into a rectangular wave series waveform over time, the audio level information that represents changes in audio level among the information included in the audio signal is suppressed to a constant level, and the temporal information is mainly used in hearing aids. The purpose of this is to transmit audio information to hearing-impaired people with a narrow dynamic range without compromising their intelligibility. Therefore, the present invention is particularly suitable as a hearing aid for people with severe hearing loss.

[Summary of the invention]

In order to achieve this object, according to the present invention, the audio waveform is compared with a reference voltage, the audio waveform is converted into a rectangular wave series waveform as time passes, and time information of the audio waveform is obtained.

[Embodiments of the invention]

FIG. 1 shows one embodiment of the present invention, and FIG. 2 is a time chart obtained for each section of FIG.

A microphone 1 converts an audio signal from a sound wave to an electrical signal, and an amplifier 2 amplifies it to a predetermined level to obtain an audio signal wave A. Next, when the wave is detected by a detector 3, an audio signal waveform B is obtained. Input this audio signal waveform B to one input terminal of the comparator 4,
The reference DC voltage from the reference voltage generator 5 is converted into a desired voltage by an attenuator 6 and applied to the other input terminal. The desired voltage means the slicing voltage C for slicing the audio signal waveform B in the comparator 4, and when the audio signal waveform B becomes equal to or higher than the slicing voltage C, the output of the comparator 4 maintains a constant level in the direction, If it is below, it works to maintain the zero level. Therefore, the function of the attenuator 6 in this case is such that when listening to conversational sounds in a place with a lot of external noise, slicing at a level higher than the noise level D removes the external noise and only listens to the voice information. Pick up and increase the signal-to-noise ratio.

In a place with little external noise, the slice level is lowered to near zero to obtain as much audio information as possible and increase clarity. The output of the comparator 4 obtained in this manner suppresses changes in the audio level included in the audio waveform signal to a constant level over time and has time information representing changes in the audio cycle. A rectangular wave series waveform E with a constant amplitude is obtained, and the power is amplified by a power amplifier 8 via a semi-fixed attenuator 7 and sent to a receiver 9.
is converted into a sound wave as one of the audio information that can be sensed by the wearer as sound. In this case, the semi-fixed attenuator 7 may be placed within the hearing dynamic range depending on the degree of hearing loss.
This is to adjust and apply the sound pressure level of the sound pressure level. In the present invention, since the audio waveform is a rectangular wave series waveform, all of the audio waveforms can easily fall within the dynamic range.

However, if the slice level is zero or near zero, time information of both the side waveform and the side waveform can be obtained as shown in Figure 3, but as the slice level increases, the side information is eliminated as shown in Figure 4. This reduces the clarity. Such a case can be solved by the following embodiment.

FIG. 5 is another embodiment of the present invention,
FIG. 6 is a time chart obtained in each section of FIG. A detailed explanation will be given below with reference to the drawings. The microphone 1 converts the sound wave into an electric signal, and the amplifier 2 amplifies it to a predetermined level to obtain the audio signal waveform F, and the positive side waveform portion of the audio signal waveform F is obtained from the side detector 3A and the side detector 3B. and the negative side waveform portion are detected, and as the detected output, an audio signal detected waveform G is obtained and given to one input of the comparator 4A. On the other hand, an audio signal detection waveform H is obtained and applied to one input of the comparator 4B. The reference DC voltage from the reference voltage generator 5 is converted into a desired voltage by an attenuator 6 and applied to the other input of the comparator 4A. The reference DC voltage of the attenuator 6 is inverted in phase by a phase inverter 10 and is applied to the other input of the comparator 4B as a reference DC voltage.
As a result, the comparator 4A obtains a rectangular wave series waveform I with a constant amplitude that contains the time information (that is, information representing periodic changes) of the positive side waveform portion of the audio signal waveform F, and the comparator 4B similarly obtains the A rectangular wave series waveform J having a constant amplitude and containing time information of the negative side waveform portion of the signal waveform F is obtained. When these two signal waveforms are added by an adder 11, a rectangular wave series summation waveform K is obtained, which is power amplified by a power amplifier 8 via a semi-fixed attenuator 7, and is applied to a receiver 9. As a result, although the time information differs depending on the slice level, even if the slice level is increased, information on the sides of the audio waveform can be obtained, so the clarity is not reduced as much as possible.

In the above embodiment, a telephone receiver is described as a converter, but it is not limited to this.
By using a vibrator in place of the handset 9, fixing the tip of the vibrator to the stapes bone, and implanting the entire body in the human body, it is also possible to use the handset 9 as an implantable middle ear implant hearing aid. It can also be used as an implantable cochlear implant hearing aid by attaching a needle electrode instead and applying electrical stimulation to the cochlea. As for the embedding method, the technology for both is secured worldwide.

In this way, if the audio waveform is clipped depending on whether it is on the slice level side or on the other side, it will take two or three constant values, regardless of the audio level.
The waveform becomes a rectangular wave series, and only the time information of the speech waveform, that is, the pitch information, is conveyed to the auditory sense.As shown in Figure 7, syllable intelligibility varies depending on the slice level, but when the slice level is zero, The closer you get, the higher the syllable intelligibility becomes, approximately 90%. Note that when syllable intelligibility is 65% or more, word and sentence intelligibility is 80-100%, and there is almost no problem in conversation. In addition, in the case of voice level information, the intelligibility gradually decreases as it approaches the HTL, but in the case of the present invention, since there is only one level as the level given to the auditory sense, a semi-fixed attenuator is used. So, even if the level is changed slightly, as long as it is included in the HTL, the clarity will not deteriorate as long as the amount of time information does not change. This means that the intelligibility does not change even if the conversational sound becomes a little quieter.

〔Effect of the invention〕

As described above, the present invention has no direct relation to the audio level, detects the audio signal over time, and provides only time information, thereby making it possible to easily bring the audio signal within the dynamic range of hearing. Moreover, voice information can be transmitted to severely hearing-impaired people with a narrow hearing dynamic range without compromising clarity, and extraneous noise can be eliminated relatively easily. Other benefits include the fact that even if the conversational sound changes slightly, the clarity remains the same.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention.
FIG. 2 is a time chart showing waveforms of various parts of the embodiment. 3 and 4 are waveform diagrams for explaining the present invention. FIG. 5 is a block diagram showing another embodiment of the present invention. FIG. 6 is a time chart showing waveforms of various parts of the embodiment. FIG. 7 is a correlation diagram showing changes in syllable intelligibility depending on slice level. 3: Detector, 4: Comparator, 5: Reference voltage generator, 6: Attenuator, 11: Adder.

Claims (1)

[Claims] 1. An audio signal wave obtained by converting an audio input using a microphone is compared with a reference voltage in a voltage comparing means, and during a period in which the audio signal wave exceeds the reference voltage, the first forming a rectangular wave series waveform signal that reaches the signal level and becomes a second signal level during a period in which the audio signal wave does not exceed the reference voltage, and uses the rectangular wave series waveform signal by an audio conversion means. A hearing aid that converts audio information into audio information that can be perceived as audio by a person. 2. A patent characterized by comprising a reference voltage adjusting means that adjusts the value of the reference voltage to prevent the rectangular wave series waveform signal from being affected by external noise superimposed on the audio input. A hearing aid according to claim 1. 3 The voltage comparison means includes a first voltage comparison section that compares a positive side waveform portion of the audio signal wave with a first reference voltage to form a first rectangular wave series waveform signal element; a second voltage comparison unit that compares a negative side waveform portion of the voltage with a second reference voltage to form a second rectangular wave series waveform signal element, and adds the first and second rectangular wave series waveform signal elements. The hearing aid according to claim 1 or 2, further comprising an adding means for transmitting the rectangular wave series waveform signal as the rectangular waveform signal.