JPH11136331A - Earset type handset - Google Patents

Abstract

(57) [Summary] [Problem] To maintain the required suppression characteristics for external noise,
Further, an earset type handset is provided which maintains an appropriate volume for a call voice and significantly improves howling stability. Kind Code: A1 A first microphone or a microphone duct placed near an mouth while being attached to an auricle, and a second microphone or a microphone duct placed farther from the mouth than the first microphone. And an electric circuit or a sound absorbing material for adjusting the sensitivity and the output phase of the first microphone or the microphone duct, so that each AC output from the first and second microphones or the microphone duct is canceled so as to cancel each other. It is configured so as to have unidirectional characteristics such that ambient noise components arriving at the second microphone side are suppressed at the combined output side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handset in a two-way simultaneous voice communication terminal, and relates to an earset type handset which can be mounted on an auricle and used for transmitting and receiving without using hands. It is.

[0002]

2. Description of the Related Art In recent years, for example, in order to avoid inconvenience in writing while talking while working in an office,
2. Description of the Related Art Hands-free handsets have been used that allow a user to talk while driving safely while driving without using a hand.

FIG. 7 shows a first conventional example of this type of earset type handset. Reference numeral 1 denotes a case formed of a synthetic resin in a substantially L-shape. A bulge 1a having a size enough to enter the entrance of the ear canal is formed on the receiver side of
Are formed. A vertically long hollow portion 1d is formed on the transmitter side, which is one long side of the case 1, and this hollow portion 1d is formed.
Microphone housings 1d ₁ and 1d ₂ are formed at both ends. Further, the microphone storage units 1d ₁ , 1
inlet 1e ₁ intake diameter of speech outside closed portion of d _2, 1e ₂
Is open. Reference numeral 2 denotes an electromagnetic or dynamic speaker which is housed and fixed by a support member 3 made of an elastic body in the vacant space 1b of the bulging portion 1a. Sound is emitted from 1c1. 4,4 'are microphones such as a small electret microphone housed fixed to the microphone housing portion 1d _1, 1d _2. 5 is a speaker 2 and a microphone 4,
The connection cord from 4 ′ is led out to the outside through the outside of the hollow portion 1d in a united state. The case 1 is provided with combining means (not shown) such as a differential amplifier for electrically combining the AC outputs of the microphones 4 and 4 'so as to cancel each other.

FIG. 8 shows a second conventional example of this type of earset type handset, wherein 1A is a case formed in a substantially L shape by a synthetic resin, and this L-shaped short side is used. A bulging portion 1Aa having a size enough to enter the entrance of the ear canal is formed on the receiver side, and a sound emitting portion 1Ac is formed at the tip of the bulging portion 1Aa. A vertically long hollow portion 1Ad is formed on the side of the transmitter which is one long side of the case 1A, and a microphone 9 such as one small bidirectional electret microphone is fixed to a substantially central portion of the hollow portion 1Ad. In addition, a sound absorbing material 10 such as Japanese paper, cotton, or the like is filled in the front and rear cavities of the microphone 9. Further, small-diameter audio inlets 1Ae ₁ and 1Ae ₂ are opened in the outside closing portion of the microphone housing 1Ad.
Reference numeral 2A denotes an electromagnetic or dynamic speaker which is accommodated and fixed in the bulging portion 1Aa by a support member made of an elastic material, and the sound from the speaker 2A is emitted from the sound emitting portion 1Ac.
From the sound hole 1Ac. 5A is a connection cord from the speaker 2 and the microphone 9, and is led outside through the outside of the cavity 1Ad in a united state.

In the earset type handset having such a configuration, first, the bulging portions 1a, 1Aa of the cases 1, 1A are fixed to the pinna, and the sound emitting portions 1c, 1Ac are inserted into the external auditory canal. In this state, the sound emitting portions 1c and 1Ac are shaped so as not to completely block the external auditory canal, and there is little feeling of obstruction so that even if external sound leaks, there is no problem in terms of safety. , 1Ac. On the other hand, the voice from the wearer is voice input 1
Microphone 9 from e ₁ , 1e ₂ , 1Ae ₁ , 1Ae ₂
The microphone 9 converts the signal corresponding to the differential synthesis of the voice input into an electric signal and sends it out from the connection cords 5 and 5A.

[0006]

In such a conventional earset type handset, the upper microphone 4 or the voice inlets 1e ₁ and 1Ae ₁ are provided beside the speakers 2 and 2A, and the lower microphone 4 '. Or audio inlet 1e ₂ , 1
Ae ₂ is configured to be located about 20 mm below the speakers 2 and 2A. Therefore, the sound leaked from the speakers 2 and 2A is largely input to the upper microphone 4 or the sound inlets 1e ₁ and 1Ae ₁ , and the microphone output differentially synthesized by the synthesizing means or the microphone 9 is shown in FIG.
As shown in (2), the bidirectional directivity is substantially exhibited, and as a result, the output becomes large. Therefore, the speakers 2, 2A
Of the microphone to the differential output of the microphone easily causes howling, and it is difficult to make a stable call at an appropriate volume.

SUMMARY OF THE INVENTION It is an object of the present invention to maintain a required suppression characteristic for external noise and maintain an appropriate volume for speech voice, and howling by sneaking from a speaker or earphone output to a microphone. It is an object of the present invention to provide an earset type handset capable of maintaining a stable call by significantly improving the stability of the handset.

[0008]

In order to achieve this object, an earset type handset according to the present invention, when two microphones are used, has a main radiating portion of a handset portion mounted on an auricle. The structure is oriented to the ear canal,
An earset-type handset that is capable of two-way communication integrated with the handset so that the handset is located outside the ear canal, wherein the handset is mounted on the pinna. A first microphone located closer to the mouth, and a second microphone located farther from the mouth than the first microphone.
And a microphone output synthesizing means for electrically synthesizing each AC output of the first and second microphones so as to cancel each other. The sensitivity of the second microphone is determined by comparing the sensitivity of the first microphone with that of the first microphone. The sensitivity is made substantially equal, the output phase of the second microphone is delayed from the output phase of the first microphone by the propagation time of a sound wave propagating through the distance between the first and second microphones, and synthesized. The output of the microphone output combining means is configured to have a unidirectional characteristic such that an ambient noise component coming from the direction of the second microphone is suppressed. When one microphone is used, the earset-type handset according to the present invention has a structure in which the main radiation direction of the handset unit is directed to the external auditory canal when attached to the pinna, and Is a two-way talkable earset type handset integrated with the handset so as to be located outside the ear canal, wherein the handset includes a microphone having bidirectionality and one of the microphones. A sound surface is connected to the first duct, the other sound receiving surface is connected to the second duct, and the opening of the first duct is directed toward the mouth;
A microphone duct formed so that an opening surface of the second duct faces in a direction opposite to the mouth, and a sound absorbing material provided on a sound receiving surface side of the microphone in the first and second ducts, The sound absorbing material of the second microphone duct is arranged such that the phase of the transmitted sound is delayed from the sound absorbing material of the first microphone duct by the propagation time of the sound wave propagating through the distance between the first and second microphone duct entrances. And the second
Unidirectional characteristic in which the sensitivity in the direction of the microphone duct is substantially equal to the sensitivity in the direction of the first microphone duct, and the ambient noise component coming from the direction of the second microphone is suppressed by the microphone output. It is configured to have.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has a structure in which the main radiating direction of a receiver unit is directed to an ear canal when mounted on an auricle, and the receiver is arranged so that a transmitter is arranged outside the ear canal. This is an earset type handset that can be used for two-way communication. Here, when two microphones are used, the microphone is placed closer to the mouth while being attached to the auricle, and is further away from the mouth than the first microphone. A second microphone disposed at a position, an electric circuit for adjusting the sensitivity and output phase of the first microphone, and electrically synthesizing each AC output of the first and second microphones so as to cancel each other. And a microphone output synthesizing means.
When one microphone is used, the transmitter includes a microphone having bidirectionality, one sound receiving surface of the microphone is connected to the first duct, and the other sound receiving surface is connected to the first duct. A microphone duct connected to the second duct, the opening of the first duct facing the mouth, and the opening surface of the second duct facing the opposite direction to the mouth; And a sound absorbing material provided on the sound receiving surface side of the microphone in the second duct. In such a configuration, according to the present invention, the sensitivity in the direction of the second microphone or the second microphone duct is made substantially equal to the sensitivity in the direction of the first microphone or the first microphone duct, and the second microphone From the output phase of the first microphone.
The sound absorbing material of the second microphone duct is synthesized from the sound absorbing material of the first microphone duct more than the sound absorbing material of the first microphone duct. Arranged so that the phase of the transmitted sound is delayed by the propagation time of the sound wave propagating through the distance between the entrances, and the ambient noise component arriving from the second microphone or the microphone duct direction is suppressed by the synthesizing means or the microphone output. I am trying to be.

[0010]

Embodiments of the present invention will be described below. FIG.
FIG. 3 is a connection diagram showing the first embodiment of the present invention in a case where two microphones are used, in a structure in which a main radiation direction of a receiver unit is directed to an external auditory canal in a state of being attached to an auricle;
An earset-type handset capable of two-way communication is integrated with the handset so that the handset is located outside the ear canal. Here, the receiver 15a is not a direct object of the present invention and is similar to the conventional example, and thus mainly shows a structure related to the transmitter. The transmitter includes a first microphone 11 that is arranged near the mouth while being attached to the auricle, a second microphone 12 that is arranged at a position farther from the mouth than the first microphone 11, and a microphone. A microphone output synthesizing circuit 20 for electrically synthesizing each AC output of the first and second microphones so as to cancel each other. 14a is a case. In the microphone output synthesizing circuit 20, the phase and amplitude adjuster 20-
1 makes the sensitivity of the second microphone 12 substantially equal to the sensitivity of the first microphone 11, and sets the output phase of the second microphone 12 to the first and second values based on the output phase of the first microphone 11. The signal is delayed by the propagation time of the sound wave propagating through the distance between the microphones, and is synthesized by the differential amplifier 20-2. Thereby, the microphone output synthesizing circuit 2
The configuration is such that a unidirectional characteristic in which an ambient noise component coming from the direction of the second microphone 12 is suppressed at an output (OUT) of 0 is obtained.

FIG. 2 is a schematic diagram for explaining the operation of noise suppression in the embodiment of FIG. 1, and includes a first microphone 11 [microphone (1)] and a second microphone 12 [microphone (2)]. Phase delay d (sec) between the microphone (1)
D = L / 300 obtained by dividing the distance Lmm between the microphone and the microphone (2) by the approximate propagation distance of the sound wave in the air for one second of 300,000 mm
If it is set to 000, the sensitivities of the microphones (1) and (2) are as follows.

(A) Sound (coming from microphone 1 direction) sensitivity Microphone (1) output: A sin ωt ω: angular frequency t: time (sec) Microphone (2) output: B sin ω (t−L / 300000-d) Synthetic output: A sinωt−B sinωt (t−L / 300000−d) Assuming that A ≒ B, composite output = 2A sinω [1/2 (L / 300000 + d)] × cosω
[t−1 / 2 (L / 300000−d)], and has a frequency characteristic of the maximum amplitude when ω (L / 300000 + d) / 2 = π / 2. When d = L / 300000, ω (L / 300000) = π / 2. The frequency is ω / 2π = 1/4 (L / 300000).

(B) Noise (coming from microphone 2 direction) sensitivity Microphone (1) output: A sinωt Microphone (2) output: B sinω (t + L / 300000-d) Composite output: A sinωt−B sinωt (t + L / 300000) −d) Assuming A ≒ B, composite output = 2A sin ω [1/2 (L / 300000−d)] × cos ω
[t−1 / 2 (L / 300000 + d)], and when L / 300000 = d, the output is erased.

Thus, the voice sensitivity has the maximum amplitude,
The noise sensitivity in the microphone 2 direction is deleted. FIG. 3 shows the directivity of the embodiment of FIG. 1 and it is understood that it has unidirectional directivity. FIG. 4 is an example of actual measurement of thinking characteristics in the case of the embodiment of FIG.
It can be seen that the sensitivity on the back side in the direction of the microphone (2) has decreased to near 20 dB.

FIG. 5 is a connection diagram showing a second embodiment of the present invention when one bidirectional microphone is used. As in the first embodiment, the receiver is mounted on an auricle. The main radiation direction of the part is directed to the ear canal, and an earset type handset capable of two-way communication integrated with the receiver so that the transmitter is arranged outside the ear canal. is there. 15b is a receiver. Here, the transmitter is a microphone 13 having bidirectionality, and one sound receiving surface of the bidirectional microphone 13 is connected to the first duct 18.
And the other sound receiving surface is connected to the second duct 19, and the opening of the first duct 18 faces the mouth,
A microphone duct formed so that an opening surface of the duct 19 is directed in a direction opposite to the mouth, and sound absorbing members 16 and 17 provided on the sound receiving surface side of the microphone in the first and second ducts. ing. The sound absorbing material 16 is sparsely arranged to form a sparse filter (16), and the sound absorbing material 17 is densely arranged to form a dense filter (17).
The sensitivity in the direction of the second microphone duct is smaller than the sensitivity in the direction of the first microphone duct. Further, the sound absorbing material 17 of the second microphone duct 19 is more than the first and second sound absorbing materials 16 of the first microphone duct 18.
Arranged so that the phase of the transmitted sound is delayed by the propagation time of the sound wave propagating through the distance between the entrances of the second microphone ducts 18 and 19, and the ambient noise component arriving from the second duct direction at the microphone output. The configuration is such that a unidirectional characteristic that is suppressed can be obtained.

FIG. 6 is a schematic diagram for explaining the operation of noise suppression in the embodiment of FIG. 5, and shows the phase delay d ₁ at the entrance of the first microphone duct 18 [microphone duct (1)] and the second delay. , The phase difference d (se) from the phase delay d ₂ at the entrance of the microphone duct 19 [microphone duct (2)].
c) is the distance Lmm between the microphone duct (1) and the microphone duct (2) is approximately 30 seconds, which is approximately the propagation distance of the sound wave in air for 30 seconds.
Assuming that d = L / 300000 divided by 0000 mm is set, the sensitivity in the microphone duct (1) and the microphone duct (2) is as follows.

(A) Voice (coming from microphone duct 1 direction) sensitivity Microphone duct 1 output: A sinω (t−d ₁ ) Microphone duct 2 output: B sinω (t−L / 300000−)
d ₂ ) Assuming A ≒ B, microphone output: A sin ω (t−d ₁ ) −B sin ω (t−L
/ 300000-d ₂ ) = 2A sinω [1/2 (L / 300000) + d
₂₋ d ₁ ] × cos ω [t−1 / 2 (L / 300000−d ₂ −d ₁ )], and ω (L / 300000 + d ₂ −d ₁ ) / 2 = π / 2
At the time, the frequency characteristic has the maximum amplitude. d ₂ −d ₁ = L / 30
At 0000, ω (L / 300000) = π / 2. The frequency is ω / 2π = 1/4 (L / 300000).

(B) Noise (coming from microphone duct 2 direction) sensitivity Microphone duct 1 output: A sinω (t−d ₁ ) Microphone duct 2 output: B sinω (t + L / 300000−)
d ₂ ) Microphone output: A sinω (t−d ₁ ) −B sinω (t + L
/ 300000−d ₂ ) Assuming A ≒ B, microphone output = 2A sin ω [1/2 (L / 300000−d ₂ +
d ₁ )] × cos ω [t−1 / 2 (L / 300000 + d ₂ −d ₁ )], and when L / 300000 = d ₂ −d ₁ , the output is erased.

As described above, the voice sensitivity has the maximum amplitude,
The noise sensitivity coming from the microphone duct 2 direction is eliminated. Also in the second embodiment, unidirectional directivity similar to that shown in FIG. 3 can be obtained.

With the above configuration, the directivity in the direction of the front microphone (1) and the directivity in the direction of the rear microphone (2) are as shown in FIG. The noise sensitivity in the rear direction can be reduced.

[0021]

As described in detail above, according to the present invention, a simple structure maintains necessary suppression characteristics against external noise and maintains an appropriate volume for speech sound. However, the stability of howling caused by the sneaking around from the output of the speaker or the earphone to the microphone can be remarkably improved, and a stable call can be maintained. Therefore,
The practical effect is extremely large.

[Brief description of the drawings]

FIG. 1 is a connection configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 3 is a characteristic diagram showing the transmission directivity of the earset type handset according to the present invention.

FIG. 4 is a graph showing an actual measurement example of the transmission directivity of the earset type handset according to the present invention.

FIG. 5 is a connection configuration diagram showing a second embodiment of the present invention.

FIG. 6 is a block diagram for explaining the operation of the embodiment in FIG. 5;

FIG. 7 is a side view including a cross section showing a structural example of a conventional earset type handset.

FIG. 8 is a side view including a cross section showing a structural example of a conventional earset type handset.

FIG. 9 is a characteristic diagram showing transmission directivity of a conventional earset type handset.

[Explanation of symbols]

1 case 1a, 1Aa bulge portion 1b vacant chamber 1c, 1Ac sound output part 1d, 1Ad cavity 1Ac ₁ sound hole 1d _1, 1d ₂ microphone housing portion _{1e 1, 1e 2, 1Ae 1} , 1Ae 2 audio inlet 2 , 2A speaker 3 support member 4, 4 'microphone 5, 5A connection cord 9 microphone 10 sound absorbing material 11 first microphone 12 second microphone 13 bidirectional microphone 14a, 14b case 15a, 15b receiver 16 sparse filter 17 dense Filter 18 First microphone duct 19 Second microphone duct 20 Synthesis circuit 20-1 Phase and amplitude adjuster 20-2 Differential amplifier

Claims (2)

[Claims] 1. A structure in which a main radiating direction of a receiver section is directed to an ear canal when mounted on an auricle, and both the receiver and the receiver are integrated so that the transmitter is arranged outside the ear canal. An earset type handset capable of two-way communication, wherein the mouthpiece is attached to the auricle and is located closer to a mouth, and is farther from the mouth than the first microphone. And a microphone output synthesizing means for electrically synthesizing each AC output of the first and second microphones so as to cancel each other. The sensitivity of the second microphone Is approximately equal to the sensitivity of the first microphone, and the output phase of the second microphone is set to be greater than the output phase of the first microphone.
A single direction in which the ambient noise component arriving from the direction of the second microphone is suppressed by the output of the microphone output combining means by delaying the sound by the propagation time of the sound wave propagating through the distance between the microphones. An earset-type handset characterized by having sexual characteristics. 2. A structure in which a main radiating direction of a receiver section is directed to an external auditory canal when mounted on an auricle, and both the transmitter and the receiver are integrated with each other so as to be arranged outside the external auditory canal. An earset type handset capable of two-way communication, wherein the handset is connected to a microphone having bidirectionality, and one sound receiving surface of the microphone is connected to a first duct,
A microphone duct formed so that the other sound receiving surface is connected to the second duct, and the opening of the first duct faces the mouth, and the opening of the second duct faces the direction opposite to the mouth. And a sound absorbing material provided on the sound receiving surface side of the microphone in the first and second ducts, wherein the sound absorbing material of the second microphone duct is more than the sound absorbing material of the first microphone duct. , The phase of the transmitted sound is delayed by the propagation time of the sound wave propagating through the distance between the entrances of the second microphone duct, so that the sensitivity in the direction of the second microphone duct is different from the sensitivity in the direction of the first microphone duct. The microphone output is made substantially equal, and the microphone output is configured to have a unidirectional characteristic such that an ambient noise component coming from the second microphone duct direction is suppressed. Earset type handset.