JP2983017B1 - Earplug type electroacoustic transducer - Google Patents

Abstract

The present invention relates to an electro-acoustic transducer such as a hearing aid or an earphone, which eliminates the conventional disadvantages of characteristic fluctuation and pain during use, and also reduces the loss of vibration energy via air conduction in a tube. It is an object to eliminate the problem. An electroacoustic transducer according to the present invention is an electroacoustic transducer having an earplug function to be worn in an ear canal,
An earplug member having flexibility and an electroacoustic conversion system for converting electric energy into vibration energy, and the vibration energy obtained by the electroacoustic conversion system is transmitted to the earplug member via a lever for transmitting vibration. Then, the earplug member is vibrated so as to be sensed as an acoustic signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be mounted in a user's external auditory canal to cut off noise, and can be used as a precise hearing test and a high-performance hearing aid system. The present invention relates to a small and lightweight earplug-type electro-acoustic transducer having functions such as an earphone for reproduction.

[0002]

2. Description of the Related Art Earpieces used for hearing tests and the like are mainly of the earpiece type, and earphones used for hearing aids and the like are mainly of the type inserted into the ear canal. Therefore, in actual use,
In the case of the earpiece type, there is a gap between the handset and the ear due to the magnitude of the pressing force between the handset and the ear and the shape of the earpiece, and external noise may occur due to changes in the frequency characteristics of the handset sensitivity and noise. Leakage may occur, resulting in a decrease in listening quality.

[0003] In the case of an earphone inserted into the ear canal, the gap between the earphone and the ear can be reduced, but there is a drawback that pain occurs over time.

[0004] In the case of a hearing aid, in the case of a bone-conducting hearing aid, the attachment condition of the bone-conducting vibrator greatly affects the characteristics of the audible sound, and a headband is required to attach it to the mastoid part where it can be best heard. . Bone conduction hearing aids are suitable for people with high levels of hearing loss, where bone conduction thresholds are close to normal.There are no concerns about acoustic trauma due to strong sound, and there are no advantages such as a feeling of pressure on the ear canal such as earplugs or earphones. However, there are drawbacks such as poor sound quality, insufficient sensitivity, and uncomfortable feeling due to pressure bonding when worn for a long time.

On the other hand, in the case of air-conducting hearing aids, electromagnetic earphones are often used, but the sensitivity is easy to obtain because the electric impedance is easily matched to the circuit.
Generally, an electromagnetic earphone is housed in a hearing aid main body, and is guided from a sound hole into an external auditory canal via a tube and earplugs. The frequency characteristics in this case are measured using a 2 cc coupler, and the design is such that a range from about 300 Hz to about 4 kHz is reproduced. Many have a peak or dip characteristic of 10 dB or more, and the gap between the earplug and the external auditory canal greatly changes the sensitivity frequency characteristic. That is, since the vibration energy generated by the vibrator is transmitted to the earplug member via the air conduction in the tube, energy conversion loss from the vibrator to air, air to the earplug member, and energy conversion during air conduction. Due to leakage or the like, the efficiency of energy transmission from the vibrator to the earplug member deteriorates. To avoid this, it is necessary to ensure correct mounting with as little gap as possible, and to secure a function that automatically corrects the characteristic fluctuation due to this effect even if some gap occurs. Becomes In addition, it is necessary to minimize energy loss caused by air conduction in the tube.

Further, the above-mentioned hearing aid receiver and hearing aid use a receiver or earphone calibrated with a pseudo-ear (a 6 cc or 2 cc coupler) and set a hearing compensation system by judging from a minimum audible value. However, to measure how the frequency characteristics of the earphone change depending on the wearing condition and how the earphone actually sounds, a complicated measurement method and a lot of time are required. That is, conventionally, the sound pressure in the vicinity of the eardrum in the ear canal is measured by an impedance audiometer equipped with a probe microphone or an ear canal insertion probe.
The frequency characteristic of the microphone has a drawback that measurement at high frequencies is particularly difficult due to the influence of the tube. That is, it is considered that the energy loss and the variation in the conduction state in the air conduction in the tube are affecting. In addition to this, the hearing aid fitting evaluation
In the sound field, hearing threshold tests are widely performed when wearing hearing aids.The sound pressure calibration method is based on placing the microphone of the sound level meter at the center of the subject's head in a sound field without the subject, and radiating from the speaker. First, the sound pressure level of the wobble tone or band noise is determined, and then the subject is placed in the sound field and the sound pressure near the microphone surface of the hearing aid is measured. Since the sound pressure characteristics fluctuate greatly even by slightly moving, it is extremely difficult to obtain accurate hearing compensation characteristics.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hearing aid or a headphone or an earphone for a hearing aid or a general audio system of a type to be inserted into an external auditory canal. In addition to eliminating fluctuations and pain during use, it also eliminates the loss of vibration energy due to air conduction in the tube, and furthermore, the sound pressure actually applied to the subject's tympanic membrane in audiovisual examinations An earplug-type electroacoustic transducer that accurately measures the level and evaluates the correct hearing ability of each subject, and based on the results, appropriately controls the sensitivity frequency characteristics of the hearing aid required for each individual To provide. In addition, in use under noise, an earplug type electroacoustic transducer having an active noise control (ACN) function for detecting a noise component of a microphone arranged in the ear and reducing the noise component is used. To provide.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an electroacoustic transducer having an earplug function to be worn in an external auditory canal, comprising a flexible earplug member and an electric plug for converting electric energy into vibration energy. An acoustic conversion system, wherein the vibration energy obtained by the electro-acoustic conversion system is transmitted to the earplug member via a lever for transmitting vibration, and the earplug member is vibrated to be sensed as an acoustic signal. The present invention provides an earplug type electroacoustic transducer characterized by the following.

That is, a small and lightweight earplug member having sufficient flexibility to fit any ears well, and an earplug through a vibration transmission lever by vibration energy generated by an electroacoustic conversion system. It is configured to drive the member directly,
It eliminates the conventional disadvantages of characteristic fluctuation and pain during use, and also eliminates the loss of vibration energy through air conduction in the tube.

An electroacoustic transducer having an earplug function to be worn in an ear canal, comprising an earplug member having flexibility and an electroacoustic conversion system for converting electric energy into vibration energy. The eardrum of the earplug member has a function of transmitting vibration energy obtained by an acoustic conversion system to the earplug member via a lever for transmitting vibration, and causing the earplug member to vibrate so as to be sensed as an acoustic signal. A first microphone for detecting a sound pressure generated in a small air chamber formed by the external auditory canal, the eardrum, and the earplug member, at a side central portion, opposite to the eardrum of the earplug member; A second microphone for detecting the sound pressure near the entrance of the ear canal located on the side, and an electric signal input to the electroacoustic conversion system is an output signal of the first microphone or the second microphone. Providing earplug type electroacoustic transducer, characterized in that obtained by selecting from one of the output signal from the output signal or the signal generator of the microphone.

That is, a function of directly measuring the sound pressure of a small air chamber, which is an acoustic space formed by the ear canal, the earplug member, and the eardrum, with a very small microphone incorporated in the earplug member, and the eardrum of the earplug member. An earplug type with an ultra-small microphone placed on the opposite side to detect external voices and noise to reduce unnecessary external listening sounds and optimal listening quality characteristics for each individual The main feature of the present invention is to provide an electro-acoustic transducer.

The prior art is an electroacoustic conversion system in which earplug members are directly driven. Microphones for detecting acoustic signals are arranged inside and outside the earplugs to ensure optimal acoustic signal transmission characteristics for each person. The point that it has a control system that can be used does not exist in the prior art.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[0014]

Embodiment 1 FIG. 1 is a basic structural view for explaining a first embodiment of the present invention, in which reference numeral 10 denotes an earphone case, and reference numeral 11 denotes a piezoelectric vibrator whose peripheral portion is fixed by the earphone case. Ein is an input terminal for inputting an electric signal to the piezoelectric vibrator, and 12 is a lever for transmitting vibration for transmitting vibration energy generated by the piezoelectric vibrator 11 to the earplug member 20. . Reference numeral 100 denotes a small air chamber formed by the earplug member 20, the human ear canal 80, and the eardrum 90.

Referring to FIG. 1, the operation of the earphone, which is a basic characteristic of the present invention, will be described first. A signal in the audio frequency band is input to the input terminal Ein. The electric signal is input to the piezoelectric vibrator 11 and is converted into vibration energy according to the level of the input electric signal. The vibration energy is transmitted to the earplug member 20 via the bulk vibration of the lever 12 without using the conventional air vibration in the tube. The vibration energy at this time is generated in the left-right direction as shown in FIG. The earplug member 20 vibrates in response to an electric signal input to the Ein, and generates acoustic energy to the small air chamber 100 in the ear formed by the earplug member 20, the external auditory meatus 80, and the eardrum 90, and When the energy excites the eardrum 90, the human perceives as sound,
Performs functional operation as an earphone.

The vibration energy generated by the piezoelectric vibrator 11 is transmitted to the earplug member 20 via the bulk vibration of the lever 12, so that the energy is efficiently transmitted. Can be directly driven. This makes it possible to transmit a powerful and reproducible sound to the small air chamber 100, which is a narrow acoustic space, and to transmit the sound with very little sound quality deterioration to the eardrum 90 via the vibration of the small air chamber 100. Can be.

Further, since the earplug member 20 having high flexibility is used, the gap between the external auditory canal 80 and the earplug member 20 can be made small, the leakage of acoustic energy can be almost eliminated, and the external noise can be reduced. Since almost all noise can be cut off, sound with very little deterioration in sound quality can be transmitted to the eardrum 90.

As one aspect of the sound quality characteristics of the earphone according to the present invention, the high sensitivity and flatness of the output sound pressure level will be described later with reference to FIG. 5, and the sound insulation effect will be described with reference to FIG.

[0019]

Embodiment 2 FIG. 2 is a basic structural view for explaining a second embodiment of the present invention, and the same components as those in FIG. 1 are denoted by the same reference numerals. Reference numeral 41 denotes a first microphone attached to the center of the earplug member 20 for detecting sound pressure generated in the small air chamber 100 in the external auditory meatus 80 formed by the eardrum 90 and the earplug member 20. It has the function of. By measuring the output electric signal of the first microphone 41 whose sensitivity frequency characteristics have been calibrated in advance, the sound pressure characteristics generated in the small air chamber 100 can be correctly known.

[0020]

Embodiment 3 FIG. 3 is a basic structural view for explaining a third embodiment of the present invention, and the same components as those in FIG. 1 are denoted by the same reference numerals. Reference numeral 42 denotes a second microphone for detecting the sound pressure near the entrance of the external auditory meatus 80 located on the opposite side of the earplug member 20 from the eardrum 90. Second microphone 42
By controlling the output electric signal to an appropriate level and inputting it to the input terminal Ein, it becomes possible to perceive a voice having a sound pressure level of Po or ambient noise as sound.

[0021]

Embodiment 4 FIG. 4 is a view for explaining a fourth embodiment of the present invention, and the same parts as those in FIGS. 1, 2 and 3 are denoted by the same reference numerals. In FIG. 4, Eout is an output terminal of an electric signal output from the first microphone 41, 190 is a level measuring unit, and 200 is data of an individual's hearing characteristics and the like based on the measurement result of the level measuring unit 190. Storage unit,
170 and 180 are a data output unit for outputting the result measured by the level measurement unit 190 and a display unit. Reference numeral 220 denotes a phase shifter that changes the phase of the output signal of the first microphone 41, and reference numeral 72 denotes a second amplifying unit. 60 is an input terminal Ein
Is an equalizer for adjusting the frequency characteristic of the electric signal inputted to the input terminal, and 71 is a first amplifier. The output of the first amplifier 71 is input to the vibrator 11. Equalizer 6
0, the first amplification unit 71 and the phase shifter 220 are set and adjusted to appropriate levels by the control unit 210 based on the result of the level measurement unit 190.

The input terminal Ein is supplied to the switch 50 by the switch 50, in addition to the output signals of the first microphone 41 and the second microphone 42, various characteristics such as an impulse signal output from the signal generator 300, a sine wave, and band noise. An electric signal for measurement is input.

Referring to FIG. 4, a method of measuring a hearing characteristic, which is one of the main features of the present invention, and setting a desired hearing characteristic of the hearing aid will be described. In this case, the switch 50 is set to E03 in a quiet environment without noise or the like.
To the input terminal Ein to send a signal in the audible frequency band or the like to a level known from the signal generator 300 (eg, 0.1
Volts). The electric signal is input to the vibrator 11 via the equalizer 60 and the first amplifier 71, and the electric signal is converted into vibration energy. Vibration energy is transmitted to the earplug member 20 via the lever 12. Ear plug member 2
0 vibrates in response to an electric signal input to Ein, and transmits acoustic energy to the small air chamber 100 in the ear formed by the earplug member 20, the external auditory meatus 80, and the eardrum 90.

FIG. 5 shows a piezoelectric earplug drive type earphone constituted by a combination of the ceramic piezoelectric vibrator 11, the lever 12, and the earplug member 20 shown in FIG. It is an output sound pressure level characteristic measured using the first microphone 41 attached to the earplug member 20. Sensitivity deviation in audible frequency band is 10dB
Although there are some degrees, no sharp peaks and valleys are generated, and it is relatively easy to correct the sensitivity frequency characteristic. 70
It has high sensitivity of dB or more and shows good flat characteristics in a frequency band from 630 Hz to 6.3 kHz.

The sound pressure level Pe generated in the small air chamber 100 is
The signal is converted into an electric signal by the first microphone 41, and the output is taken out to Eout. At this time, if the value of Pe is obtained as the minimum level at which the subject is detected as sound, this value is evaluated as the minimum audible value for the subject.

The output sound pressure level characteristics shown in FIG. 5 also apply to the first to third embodiments. The high flatness in the frequency band from 630 Hz to 6.3 kHz with a high sensitivity of 70 dB or more is due to the fact that the vibration energy generated by the piezoelectric vibrator 11 is applied to the earplug member 20 via the bulk vibration of the lever 12. , The energy is efficiently transmitted, and since the earplug member 20 having high flexibility is used, the leakage of acoustic energy can be almost eliminated, and This can be said to be a reflection of the fact that almost all noise was cut off.

FIG. 6 shows the sensitivity frequency characteristics of the ultra-compact electret condenser microphones used for the first and second microphones 41 and 42 of the present invention. It can be seen that the filter has flat characteristics from the low band to the high band.

As described above, the first microphone 4
By calibrating the sensitivity of the output electric signal level to the input sound pressure level of 1, the value of Eout is measured by the level measuring section 190 every time the frequency is changed, so that the minimum audible value of the subject can be correctly obtained. Frequency characteristics can be known. The value measured by the level measurement unit 190 can be confirmed on the display unit 180 or the data output unit 170. Further, the value of each level of the level input from the signal generator 300 is recorded in the storage unit 200 as an individual hearing characteristic.

Next, a case will be described in which a sound level which is easy for the user to hear is checked, and the result is applied to a hearing aid. In this case, each time the frequency of the signal generator 300 is changed, the equalizer 60 and the first amplifying unit 71 are adjusted so as to have a sound level that the subject perceives to be easy to hear, similarly to the procedure described above. The sound pressure level Pe at this time is
Eout obtained as an output of the first microphone 41
Can be obtained from the value of This value is recorded in the storage unit 200 for each frequency. When the measurement in the necessary frequency range is completed, the storage unit 200 stores the hearing correction value (included in the individual hearing characteristics) reflecting the individual hearing characteristics of the user. The control unit 210 controls the equalizer 60 to realize the correction value for each frequency obtained as described above, and realizes the output E02 of the second microphone 42 for capturing an external sound signal provided near the entrance of the ear canal. Ei
The switch 50 is switched so as to be introduced into the n. At this time, by adjusting the gain of the first amplifying unit 71 to an appropriate level manually or automatically, an external sound signal is realized with a frequency characteristic and a desired sound volume that are easy for each user to listen to. A hearing aid that can be heard can be provided.

Next, a description will be given of a so-called active noise control function operation for removing noise components and operating when using under noise, which is one of the main features of the present invention. In FIG. 4, the eardrum for detecting sound and the entrance of the ear canal are acoustically separated by an earplug member 20. FIG. 7 shows the results of measuring the sound insulation effect of the earplug member for 15 subjects by the method according to the present invention. This is the sound pressure level Po generated at the entrance of the ear canal.
Is measured by the second microphone 42, and the difference from the sound pressure level Pe transmitted through the earplug member 20 and measured by the first microphone 41 at this time is obtained and shown. From this figure, even at low frequencies with low sound insulation, about 15 dB,
It can be seen that a sound insulation volume of 20 to 30 dB can be obtained at a high frequency of 1 kHz or more.

The characteristics shown in FIG. 7 can be applied to the first to third embodiments. The reason why such a high sound insulation effect was obtained is that the earplug member 20 having high flexibility is used, so that the external auditory canal 80
It can be said that the gap between the earplug member 20 and the earplug member 20 can be almost eliminated, and the noise from the outside can be almost blocked.

As described above, although a certain amount of sound insulation can be obtained by using earplugs, there are many situations where a higher noise removal amount is required under high noise. In the present invention, this is made possible by the following procedure. Switch 50
Is connected to E01. The output of the first microphone 41 changes its phase level in the phase shifter 220 and the amplifying unit 72, and then is input to the vibrator 11 via the equalizer 60 and the amplifying unit 71, and is passed through the lever 12 to the earplug member 20. Vibrates. At this time, the characteristics of the equalizer 60, the phase shifter 220, and the amplifier 72 are adjusted and changed by the controller 210 so that the output level of the microphone 1 becomes substantially 0 in the level measuring unit 190. Thus, the sound pressure level on the eardrum surface can be set to zero.

As is apparent from these effects, in addition to the accurate measurement of the hearing characteristics and the proper setting of the hearing characteristics of the hearing aid which could not be realized by the prior art, the effects of removing noise under high noise can be obtained. Will be able to do it.

[0034]

As described above, in the earplug type electroacoustic transducer according to the present invention, the vibration energy generated by the piezoelectric vibrator is transmitted to the earplug member through the bulk vibration of the lever. Energy is efficiently transmitted, and favorable flat characteristics are exhibited with favorable sensitivity. In addition, since a highly flexible earplug member is used, leakage of acoustic energy can be almost eliminated, and a good shielding effect against external noise can be obtained.

Also, in the earplug type electroacoustic transducer, a very small microphone is arranged inside and outside of the earplug member, and the output characteristics of each microphone are adjusted and input to the earphone section, whereby the earplug member is provided. There is an advantage that it is possible to realize a hearing aid having a listening quality adapted to the user by vibrating the sound and to provide a noise canceling function with a reduced noise level.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment according to the present invention.

FIG. 2 is a configuration diagram of a second embodiment according to the present invention.

FIG. 3 is a configuration diagram of a third embodiment according to the present invention.

FIG. 4 is a configuration diagram of a fourth embodiment according to the present invention.

FIG. 5 shows a sound pressure level frequency characteristic of the earphone according to the present invention.

FIG. 6 shows sensitivity frequency characteristics of the electret condenser microphone used in the present invention.

FIG. 7 is a sound insulation characteristic of the earphone according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 earphone case 11 vibrator 12 lever 20 earplug member 41 first microphone 42 second microphone 50 switch, 60 equalizer 71 first amplifier 72 second amplifier 80 external auditory canal 90 eardrum 100 small air chamber 170 data output Unit 180 display unit 190 level measurement unit 200 storage unit 210 control unit 220 phase shift unit 300 signal generation unit, Pe sound pressure level in small air chamber Po sound pressure level near the entrance of ear canal Ein electric signal input terminal Eout electric signal output terminal

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji 158 Hirashidai, Nagano City, Nagano Prefecture (72) Inventor Mizuhiro Tobita 1-3-1 Gotenyama, Musashino City, Tokyo NTT Advanced Technoro (72) Inventor Yamato Sato 1-3-1 Gotenyama, Musashino-shi, Tokyo NTT Advanced Technology Co., Ltd. Examiner Yoji Sugasawa (56) References Registered Utility Model 3035669 (JP , U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H04R 25/00-25/04

Claims (5)

(57) [Claims] An electroacoustic transducer having an earplug function to be worn in an ear canal, comprising: an earplug member having flexibility; and an electroacoustic conversion system for converting electric energy into vibration energy. vibration energy obtained by the electroacoustic transducer system through the lever for vibration transmission conducted to the earplugs member, by vibrating the earplugs member, said earplug
Vibration of the small air chamber in the ear formed by the member, the ear canal and the eardrum
An earplug-type electro-acoustic transducer characterized by being sensed as an acoustic signal through motion . 2. A first detecting means for detecting a sound pressure generated in a small air chamber formed by the ear canal, the eardrum, and the earplug member at a central portion of the earplug member on the eardrum side. An earplug type electro-acoustic transducer characterized by having a microphone of (1). 3. The earplug type according to claim 1, further comprising a second microphone for detecting a sound pressure near the entrance of the ear canal located on the opposite side of the earplug member from the eardrum. Electroacoustic transducer. 4. An electroacoustic transducer having an earplug function to be worn in an ear canal, comprising: an earplug member having flexibility; and an electroacoustic conversion system for converting electric energy into vibration energy. The eardrum of the earplug member has a function of transmitting vibration energy obtained by an acoustic conversion system to the earplug member via a lever for transmitting vibration, and causing the earplug member to vibrate so as to be sensed as an acoustic signal. A first microphone for detecting a sound pressure generated in a small air chamber formed by the external auditory canal, the eardrum, and the earplug member, at a side central portion, opposite to the eardrum of the earplug member; A second microphone for detecting the sound pressure near the entrance of the ear canal, which is located on the side of the ear, where an electric signal input to the electroacoustic conversion system is an output signal of the first microphone or the second microphone. Earplug type electroacoustic transducer, characterized in that obtained by selecting from one of the output signal from the output signal or signal generator Rohon. 5. An electroacoustic transducer having an earplug function to be worn in an ear canal, comprising: a flexible earplug member; and an electroacoustic conversion system for converting electric energy into vibration energy. The eardrum of the earplug member has a function of transmitting vibration energy obtained by an acoustic conversion system to the earplug member via a lever for transmitting vibration, and causing the earplug member to vibrate so as to be sensed as an acoustic signal. A first microphone for detecting a sound pressure generated in a small air chamber formed by the external auditory canal, the eardrum, and the earplug member, at a side central portion, opposite to the eardrum of the earplug member; A second microphone for detecting a sound pressure near the entrance of the ear canal located on the side of the ear, and based on a measurement value of an output signal of the first microphone or the second microphone, a hearing characteristic of an individual. A storage unit for storing, earplug type electroacoustic transducer, characterized in that to control the electrical signal to be input to the electro-acoustic transducer system according to the hearing characteristic of the stored the personal in the storage unit.