JPH01176199A - Ear microphone - Google Patents

Abstract

PURPOSE:To prevent mis-operation of state changeover from reception into transmission unexpectedly or to avoid unpleasant sound from being given to an opposite party due to occurrence howling by a converting element caused by sound pressure energy by communicating a space formed between a front face of an inserting body and an eardrum to an external part via a duct. CONSTITUTION:A duct 15 connected between an outer skin and a front face of an insertion body 1 is formed. That is, the duct 15 is formed by a slot 1e, holes 7a, 8b, 14a and the front face of a sound opening 1d is communicated to an external part by the duct 15 via the outer skin 14. The enclosed space between the sound opening 1d of the inserting body 1 and the eardrum caused by the loading of the inserting body 1 into the ear by the user is communicated externally through the duct 15. When the sound pressure in the space is increased by the sound guide pipe 3, it is escaped through the duct 15 to keep the pressure in the space to a prescribed value or below. Thus, no sound from the sound guide pipe 3 is propagated to the conversion element 5 and occurrence of howling is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is useful for two-way communication with a person in a remote location in a situation where hands cannot be used, such as at a construction site such as a construction site or on an automatic military telephone. In other words, bone conduction audio signals from the ear canal wall are electrically converted to transmit audio.
The present invention also relates to an ear microphone that guides sound sent from an external receiver to the ear canal via a sound conduit.

[Prior Art] There has been no ear microphone of this type that can withstand use under external noise and that is integrated with a sound conduit to allow two-way communication with one ear.

That is, when used in a noisy environment, as the level of the audio signal passing through the sound pipe increases, the audio signal may leak to the vibroelectric transducer side through mechanical tongue coupling and approach the user's audio level. As a result, in two-way calls using a single carrier frequency with a voice-based automatic transmission/reception switching device (■○ Therefore, switching had to be done manually, or at least one hand had to be used for communication. Furthermore, in wired two-way communication and wireless two-way communication using two carrier frequencies, due to this mechanical acoustic coupling, howling occurs as the level of the received audio signal increases, making communication impossible.

Therefore, the present applicant focused on the fact that the energy of bone-conducted sound vibrations obtained from the wall of the ear canal is relatively large, and that the sound output signal of the ear microphone does not deteriorate significantly even when the effective load weight of the ear microphone is around several grams. By constructing the sound pipe from a material with a large mass and arranging the sound pipe via an elastic member to form an independent vibration system, vibrations caused by the audio signal passing through the sound pipe are difficult to be transmitted to the conversion element, and both We have developed an ear microphone (for example, Japanese Patent Laid-Open No. 188994/1983) that solves the problem caused by the transmission of a receiving side audio signal to the transmitting side during two-way voice communication.

[Problem that the invention seeks to solve]

By the way, when the ear microphone described above is worn in the ear, a sealed space is formed between the front surface of the ear microphone and the eardrum. When sound from the ear microphone is emitted into this space, the sound pressure level within the space rises, and this energy is transmitted to the vibrating electric transducer such as a piezo element that is the microphone, causing howling. There is a problem in that the sound is emitted from the speaker of the communicating party, and in the case of two-way communication using a single carrier frequency, a malfunction occurs and the state cannot be switched from the receiving state to the transmitting state.

[Means for solving problems]

The present invention solves the above-mentioned problems and prevents howling by opening the sealed space formed between the front surface of the ear microphone and the eardrum to the outside by using a duct that communicates the front surface of the ear microphone with the outside. The device includes an insert body that is sized to be inserted into the external auditory canal and has a through hole and an insertion hole formed therein, and a a vibratory electric transducer such as a piezo element that detects bone conduction vibration of the insert;
A damper made of rubber or the like is fitted into the through hole of the insert, and the damper is supported by the damper, one end is connected to the sound conducting pipe from the speaker, and the other end is located at a position recessed from the opening of the through hole. The ear microphone is equipped with an open sound conduit, and has a sound emitting hole formed in the wall surface to allow the sound emitted from the sound conduit to escape to the outside through the wall surface forming the through hole. Ru.

(Function) The ear microphone of the present invention converts bone conduction sound vibrations generated when the wearer speaks into electrical signals using a vibroelectric conversion element, and radiates the signals as radio waves to the communicator. Receiving radio waves and emitting sound through a speaker, and emitting sound from the speaker into the listener's ear canal from a sound emitting opening through an elastically supported sound conduit, and the sound emitting opening A sealed space formed by the ear microphone and the eardrum is communicated with the outside through a duct formed in the ear microphone, and the sound pressure level in the space is prevented from increasing to prevent howling.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described with reference to the drawings.

Reference numeral 1 denotes an insert body made of a large material such as die-cast zinc to be inserted into the ear canal of the listener, and its outer periphery is covered with a soft plastic coating 2. The insert body 1 is provided with a through hole 1a, an insertion hole 1b, and a sound emitting hole 1c communicating with the outside in a thin portion of the through hole 1a.

Note that a sound emitting hole 2a is also formed in a portion of the plastic coating 2 corresponding to the sound emitting hole 1c. Reference numeral 3 denotes a sound conduit inserted into the through hole 1a of the insert 1 while being supported by a ring-shaped damper 4 made of an elastic material such as rubber, and is constituted by a metal pipe with a large mass.

One end of this sound pipe 3 is connected to the sound emitting opening 1d of the insert body 1.
It opens in a deeper position. 5 is the above insert 1
A vibratory electric transducer (hereinafter referred to as a transducer) such as a piezo element fixed in the insertion hole lb via the holding member 5a.
As shown in FIG. 3, the vibration direction is perpendicular to the sound pipe 3. That is, the length of the piezo element which is the conversion element 5 is l1m south, and the width I
N and the thickness is 0.6 mm, this piezo element will vibrate in the thickness direction, so it is installed so that the sound pipe 3 is located in the width direction. Note that 6 is a shield plate.

Reference numeral 7 denotes an elastic member made of natural rubber, synthetic rubber, etc. that covers the rear part of the insert 1, and has a hollow space in the center. Reference numeral 8 denotes an outer body made of the same material as the above-described insert 1 that covers the outer periphery of the elastic member 7, and a hole 8a is formed in the same plane as the sound pipe 3 and the conversion element 5, and a bush 9 is inserted into this hole 8a. It is fitted. A metal pipe 10 is fitted into the bush 9, and one end of the metal pipe 10 and the tuning fork 3 are connected by a tube 11.

Further, the other end of the metal pipe 10 is connected to the sound emitting surface of an external speaker 13 via a pipe 12 made of soft plastic. - The lead wire 5b from the force transducing element 5 is inserted into the bush 9 in parallel with the pipe 12 and led out. Reference numeral 14 denotes a plush outer skin that covers the outer periphery of the outer body 8.

The present invention is characterized in that a duct 15 is formed that communicates with the front surface of the insert body 1 and the outer skin. That is, grooves 1e are formed at two opposing locations on the outer peripheral surface of the insert 1, and holes 7a are formed in the elastic member 7 in communication with the grooves 1e and located away from the central cavity. Holes 8b and 14a are also connected to the outer body 8 and the outer skin 14 in communication with this hole 7a.
was formed. This groove 1e, holes 7a, 8b, 1
4a forms a duct 15, and through this duct 15, the front surface of the sound emitting opening 1d communicates with the outside via the outer skin 14. Note that this duct 15 does not need to communicate with the outside through the outer skin 14, and may communicate with the outside at a portion exposed from the external auditory canal when worn on the ear.

Although not shown, the pipe 12 connected to the sound pipe 3 is connected to the speaker 13 in the receiver, and the lead wire 5b is connected to the transmitter.

Next, the operation of the ear microphone having the above structure will be explained.

When the user speaks now, bone conduction sound vibrations from the ear canal wall are transmitted to the insert 1 and transmitted to the conversion element 5, where it is converted into an electrical signal and sent to the transmitter via the lead wire 5b. It is radiated as radio waves from the antenna.

By the way, vibrations transmitted from the outside via the lead wire 5b and the pipe 12 are absorbed by the vibration system made of the spring elasticity of the outer body 8, the lead wire 5b, the elastic member 7, and the tube 11. Further, vibrations directly applied to the outer body 8 are absorbed by the vibration system of the insert body 1, the elastic member 7, the lead wire 5b, and the tube 11.

In any of the above cases, it is desirable that the resonance frequency of each resonance system is outside the low range of the effective sensitivity frequency band (for example, 300 to 3300) i Z of the conversion element 5.

Therefore, the weight of the insert body 2 and the outer body 8 is large, and the elastic modulus of the elastic member 7, lead wire 5b, and tube 11 must also be large. In particular, the elastic member 7 and the lead wire 5b
When the elastic modulus of the tube 11 is large, the effective load weight of the transducer element 5 against the external auditory canal sound vibration is approximately only the insert body 1, and the weight of the outer body 8 has almost no influence, thereby avoiding a decrease in the audio signal output. .

On the other hand, the external signal received by the receiver is converted into sound by the speaker 13, guided to the sound pipe 3 via the pipe 12, metal pipe 10, and tube 11, and emitted into the ear canal.

Here, the sound pipe 3 is vibrated by the vibration energy of the sound passing through the sound pipe 3, but the sound pipe 3 It is absorbed by the vibration of the damper 4 and transmitted to the outside of the damper 4 in a damped manner. Note that the above-mentioned resonance frequency is also desirably outside the low range of the effective sensitivity frequency band of the conversion element 5. For this purpose, it is desirable that the sound guide tube 3 has a large mass and the damper 4 has a large elastic coefficient.

In addition, in this embodiment, the conversion element 5 is mounted in a direction in which the vibration direction of the conversion element 5 is orthogonal to the sound pipe 3, so that even if a small amount of vibration leaks from the sound pipe 3, the conversion can be performed. Element 5 does not vibrate and therefore never switches to the receiving side.

Furthermore, in this embodiment, when the ear microphone according to the present invention is installed in the ear, the sound emitting opening 1d may be accidentally opened.
If the sound emitting hole IC formed in the insert body 1 and the plastic coating 2 are blocked with a finger, the sound from the sound conduit 3 will be trapped in the through hole 1a and the sound pressure level will increase. Since the sound is emitted to the outside through the sound emitting hole 2a, the sound pressure level within the through hole ld does not increase, and therefore, howling due to the conversion element 5 does not occur.

In the present invention, the sound emitting opening 1 of the insert 1 that is generated when the user wears the insert 1 in the ear
Since the sealed space between d and the eardrum is communicated with the outside through the duct 15, when the sound pressure level in the space increases due to the sound conduit 3, it is released through the duct 15 to maintain the pressure in the space below a certain value. Therefore, the sound from the sound pipe 3 is not transmitted to the conversion element 5, and the occurrence of howling is prevented.

In the above-described embodiment, the damper 4 is a ring damper, but this is because the outer periphery of the sound pipe 3 and the through hole 1
An elastic material may be filled in the entire space between a and a. Further, the speaker is not limited to an external speaker, but may be a built-in speaker. Further, in this embodiment, the lead wire 5b is drawn out in a direction parallel to the vibration direction of the conversion element 5, but the lead wire 5b can be drawn out in any direction such as a direction perpendicular to the vibration direction.

〔Effect of the invention〕

As described above, the present invention provides a vibrating electric transducer such as a piezo element in an insert inserted into the external auditory canal, as well as a sound conduit connected to an external speaker, and uses a material with a large mass for the sound conduit. Moreover, since this sound pipe is installed inside the insert via a damper such as rubber, even if the sound pipe vibrates due to audio vibration energy from external spill force, this vibration will be absorbed by the damper etc. Therefore, even in bidirectional communication using a single carrier frequency, there is no possibility of switching to the transmitting side at the time of reception due to malfunction.

In addition, since the space formed between the front surface of the insert and the eardrum is communicated with the outside through the duct, the sound pressure level does not rise above a certain level even when sound is emitted from the sound pipe, and therefore, the sound pressure level does not rise above a certain level. This has the effect of preventing the conversion element from generating howling due to the pressure energy, making the recipient of the transmission feel uncomfortable, and preventing malfunctions such as switching from reception to transmission inadvertently.

[Brief explanation of the drawing]

The drawings show an embodiment of the ear microphone according to the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a longitudinal cross-sectional view of the same, and FIG. 1-insertion body, 1a-through hole, 1b-insertion hole, 1cm sound emission hole, ld-sound emission opening, 3-sound conduit, 4-damper, 5
- conversion element, 7 - elastic member, 15 - duct.

Claims (1)

[Claims] An insert body formed in a size to be inserted into the external auditory canal and having a through hole and an insertion hole formed therein, and detecting bone conduction vibrations of the insert body conducted from the external auditory canal into the insertion hole of the insert body. A vibration-electric conversion element such as a piezo element, a damper made of rubber or the like fitted into the through hole of the insert, supported by the damper, one end connected to a sound conducting pipe from a speaker, and the other end passed through. and a sound conduit opened at a position deeper than the opening of the hole, and when the insert is attached to the ear, the space formed by the front surface of the insert and the ear hole is exposed to the outside. An ear microphone characterized by forming a duct for communication with the ear microphone.