JP2012231371A - Stereo earphone and sound amplification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereo earphone with which excellent feelings of wearing and audible sound quality can be obtained.SOLUTION: A stereo earphone comprises a plug (14), a cord (15) of which one end side is connected to the plug, a branch part (13) which is provided at another end side of the cord (15), includes a first microphone (13b) and extends the cord (15) while branching it into a first branch cord (11b) and a second branch cord (12b) longer than the first branch cord, first and second earphone body parts (11a and 12a) which are connected to distal ends of the first and second branch cords (11b and 12b) and mounted in both ears (ER and EL) of a user (US), and a sound collection part (16) which includes a second microphone (16b) and is provided in the second branch cord (12b). The second branch cord (12b) has such a length as to be pulled around to the back side of the neck while positioning the cord (15) at a front side of the user and mounting the first and second earphone body parts (11a and 12a) into both the ears (ER and EL).

Description

  The present invention relates to a stereo earphone and an audio amplifying system, and more particularly, a stereo earphone including a pair of sound pickup units each having a microphone on a cord connecting a plug and a pair of earphone main body parts, and a stereo earphone and a plug thereof. The present invention relates to a sound amplifying system having a connected sound amplifying main body and configured to amplify a sound signal picked up by a pair of microphones and output the amplified signal to a pair of earphone main bodies.

In order to assist hearing, devices configured to pick up surrounding sounds with a microphone, amplify the picked-up sound signals, and listen with earphones are sold as hearing aids and sound collectors.
As a specific example, a voice amplification main body unit including a microphone and a circuit for amplifying a voice signal from the microphone, a cord for connecting to the voice amplification main body unit, and amplification supplied from the voice amplification main body unit via the cord 2. Description of the Related Art There is a so-called pocket type audio amplifier including an earphone unit having an earphone main body unit that outputs an audio signal as sound.
Hereinafter, a form in which a cord is connected to a sound amplification main body and the earphone unit and the sound amplification main body are integrated is referred to as a sound amplification system.

For example, Patent Document 1 discloses a pocket type audio amplifier system in which an earphone unit is detachably integrated with an audio amplification main body unit.
This system includes a pair of microphones in the sound amplification main body, and has a function of amplifying surrounding sounds picked up by each microphone. The earphone parts are a left-ear earphone main body and a right-ear earphone main body. And a cord that extends from each earphone main body and connects to the audio amplification main body.

  In general, as the earphone part, the left earphone body part for the right ear and the earphone body part for the right ear are connected to the ends of two cords branched from one cord connected to the sound amplification main body part. There are known so-called stereo earphones arranged respectively.

JP 2009-290383 A

By the way, in order to listen to the surrounding sound with a sense of presence, including the determination of the direction of sound arrival, the left and right microphones are provided, and the arrangement positions are as close to the left and right ears as possible. It is desirable to do.
Therefore, although it is considered to incorporate a microphone with a speaker in each earphone main body that is worn on the left and right ears, the surrounding sound picked up by the microphone is amplified and emitted from the nearest speaker. There is a problem that a phenomenon that hinders the improvement of the quality of the listening sound easily occurs and the improvement thereof is difficult.

In order to solve this problem, it has been studied to arrange a microphone on the cord between the earphone main body and the sound amplifying main body without incorporating the microphone in the earphone main body.
However, the cord that should be light in weight becomes heavier due to the arrangement of the microphone, and it is difficult to obtain a good wearing feeling because the heavy cord hangs down from the ear with the earphone main body attached to the ear, When the audio amplification main body is held in a belt or pocket in use, the position of the cord from the audio amplification main body to the earphone main body is not stable, and the rubbing sound with the clothes is likely to be collected. There are many items that need to be improved, such as the fact that quality may be degraded.

  Therefore, the problem to be solved by the present invention is to provide a stereo earphone and a sound amplification system that can provide a good wearing feeling and a good listening sound quality even if a microphone is provided on the cord. There is.

In order to solve the above problems, the present invention has the following configuration as means.
1) A plug (14), a cord (15) having one end connected to the plug (14), and provided on the other end of the cord (15), having a first microphone (13b) and the cord (15) is branched into a first branch cord (11b) and a second branch cord (12b) that is longer than the first branch cord (11b) and extends from the opposite side of the plug (14). First and second connected to the branch (13) and the ears (ER, EL) of the user (US) connected to the tips of the first and second branch cords (11b, 12b), respectively. An earphone main body portion (11a, 12a) and a sound collecting portion (16) provided on the second branch cord (12b) having a second microphone (16b),
In a state where the cord is positioned on the front side of the user (US) and the first and second earphone main body parts (11a, 12a) are attached to both ears (ER, EL) of the user (US), The second branch cord (12b) is a stereo earphone having a length that can be routed to the rear side of the neck (US2) of the user (US).
2) A distance (L13c) between the branch part (13) and the first earphone body part (11a), and between the sound collecting part (16) and the second earphone body part (12a). The stereo earphone (1) according to 1), characterized in that the distance (L16c) is substantially equal.
3) A plug (74), a first cord (75) having one end connected to the plug (74), and a first earphone main body provided on the other end of the first cord (75) (71a), a second cord (72b) having one end connected to the first earphone main body (71a) and the other end connected to the second earphone main body (72a), and the second cord A first sound collection unit (73) having a first microphone (73b) and a second sound collection unit (76) having a second microphone (76b), which are provided apart from each other on (72b); With
The second cord (72b) is a stereo earphone characterized in that the first and second earphone main body portions (71a, 72a) have a length that can be simultaneously worn on both ears of a user. is there.
4) The distance (L73c) between the first sound collecting unit (73) and the first earphone main body (71a), the second sound collecting unit (76), and the second earphone main body. The stereo earphone (7) according to 3), characterized in that the distance (L76c) to the part (72a) is substantially equal.
5) The stereo earphone (1, 7) according to any one of 1) to 4), an amplifier circuit (2b1) for amplifying an input audio signal and outputting it as an amplified audio signal, and the plug (74) Amplifying system comprising: audio amplifying main body (2) having a terminal portion (2f) connected to and integrated with each other and configured to input the audio signal and output the amplified audio signal Because
The audio signal input to the amplifier circuit (2b1) is the audio signal output from the first and second microphones (13b, 16b) (73b, 76b)), and is output from the amplifier circuit (2b1). The audio amplification system (50) is configured to supply the amplified audio signal to the first and second earphone main body portions (11a, 12a) (71a, 72a).

  According to the present invention, even if a microphone is provided on the cord, it is possible to obtain an effect that the feeling of wearing is good and the quality of listening sound is good.

It is a figure for demonstrating the Example of the audio | voice amplification system of this invention. It is sectional drawing for demonstrating the principal part in the Example of the stereo earphone of this invention. It is sectional drawing for demonstrating the other principal part in the Example of the stereo earphone of this invention. It is a figure for demonstrating the usage type in the Example of the audio | voice amplification system of this invention. It is a figure for demonstrating the other Example of the stereo earphone of this invention. It is sectional drawing for demonstrating the principal part in the other Example of the stereo earphone of this invention. It is sectional drawing for demonstrating the other principal part in the other Example of the stereo earphone of this invention. It is typical sectional drawing for demonstrating another principal part in the other Example of the stereo earphone of this invention. It is a figure for demonstrating the usage type in the other Example of the audio | voice amplification system of this invention. It is sectional drawing for demonstrating the modification in the Example of the stereo earphone of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.

FIG. 1 is an external perspective view showing an embodiment of a sound amplification system of the present invention.
The audio amplification system 50 according to the embodiment includes an earphone unit 1 that is a stereo earphone and an audio amplification main unit 2.
In general, the sound amplification system 50 includes earphone main body portions 11a, 12a and microphones 13b, 16b in which the earphone portion 1 has a speaker (not shown), and a sound amplification main body portion that receives sound signals collected by the microphones 13b, 16b. 2 can be amplified by a predetermined amount and output as sound from the speakers of the earphone main body portions 11a and 12a.

First, the earphone unit 1 will be described in detail.
The earphone unit 1 includes earphone body parts 11a and 12a attached to the right and left ears, branch cords 11b and 12b extending from the earphone body parts 11a and 12a, and a branch code 11b and a branch code 12b. Provided in the middle of the branching cord 12b, the base branching portion 13, the plug 14 connected to the terminal 2f of the audio amplification main body 2, the basic cord 15 connecting the plug 14 and the branching portion 13 And a sound collection unit 16.

  The earphone main body portions 11a and 12a each have a built-in speaker (not shown in FIG. 1), and can emit sound into the ear canal when the earphone main body portions 11a and 12a are attached to the ears.

As shown in FIGS. 1 and 2, the branching section 13 includes a resin case 13a and a microphone 13b housed in the internal space V13. A sound collecting hole 13c is formed as a through hole in the case 13a, and the microphone 13b collects surrounding sound through the sound collecting hole 13c and outputs a sound signal. Therefore, the branching unit 13 also functions as a sound collecting unit.
The basic cord 15 extends from one end (the lower end in FIGS. 1 and 2) of the case 13a, and the branch cord 11b and the branch cord from the end 13a1 (the upper end in FIGS. 1 and 2) on the other end side. 12b extends.
This end portion 13a1 serves as a branch point between the branch code 11b and the branch code 12b.
Therefore, the branching portion 13 is disposed in the basic cord 15.
As shown in FIG. 2, a sound quality adjusting filter 13d formed of a nonwoven fabric or the like may be disposed between the microphone 13b and the sound collection hole 13c.

As shown in FIGS. 1 and 3, the sound collection unit 16 includes a case 16 a having substantially the same shape as the branching unit 13 and a microphone 16 b accommodated in the internal space V <b> 16. A sound collecting hole 16c is formed as a through hole in the case 16a, and the microphone 16b collects surrounding sound through the sound collecting hole 16c and outputs a sound signal.
Further, as shown in FIG. 3, a sound quality adjusting filter 16d formed of a nonwoven fabric or the like may be disposed between the microphone 16b and the sound collection hole 16c.

Since the branch cord 12b is provided with a sound collection unit 16 in the middle thereof, the output signal line 12ba (see FIG. 3) supplied to the earphone main body 12a and the microphone 16b are provided between the case 16a and the branch unit 13. A composite code 12b1 is formed by combining an input signal line 16bb (see FIG. 3) for supplying the output audio signal toward the plug 14.
A single cord 12b2 having only an output signal line 12ba is provided between the case 16a and the earphone main body 12a.

  On the other hand, the branch code 11b is a code for only the output signal line 11ba supplied to the earphone main body 11a.

The basic cord 15 has two output signal lines 11ba and 12ba supplied to the earphone main body 11a and the earphone main body 12a, and two input signal lines 13bb and 16bb from the branching unit 13 and the sound collecting unit 16, respectively. It is a composite code.
Accordingly, the plug 14 and the terminal portion 2f to which the plug 14 is attached and detached (details will be described later) have at least five terminals when the output signal and the input signal have a common ground line, and each has an independent signal. Can be exchanged. Note that the plug 14 and the terminal portion 2f may be integrally configured so that they cannot be attached and detached.

The branch code 11b and the branch code 12b have different lengths.
Specifically, as shown in FIG. 1, a distance L11 from the end 13a1 of the case 13a of the branching portion 13 to the earphone main body 11a is different from a distance L12 from the end 13a1 to the earphone main body 12a. L11 <L12.
Here, the reference positions of the earphone main body portions 11a and 12a are the reference positions CL11 and CL12 corresponding to the center of the ear canal direction when they are attached to the ears (the top and bottom directions are the up and down directions in FIGS. 1 and 2). Is).
This form is called a so-called U-shaped cord. When the earphone main body portions 11a and 12a are worn on the ear, the longer branch cord 12b in the earphone portion 1 is turned to the back side of the neck and turned to the shoulder. It is a form that can be mounted so as to ride (hereinafter also referred to as neck mounting).
Here, the branch cord 12b is positioned such that the basic cord 15 is positioned on the front side of the user's body and the earphone main body portions 11a and 12a can be routed to the back side of the user's neck with the earphone main body portions 11a and 12a attached to both ears of the user. have.
When L11 and L12 are, for example, L11 = 20 to 150 mm and L12 = 300 to 500 mm, a particularly good feel can be attached to the neck.

In the embodiment, the combined length of the shorter branch cord 11b and the basic cord 15 is such that the plug 14 is attached in a state where the earphone main body 11a is attached to the ear and the branch cord 11b and the basic cord 15 are naturally hung. It is supposed to reach the waist.
Moreover, this length should just be made into the grade which the plug 14 reaches a breast in the form which accommodates the audio | voice amplification main-body part 2 in a breast pocket, for example.

In the earphone unit 1, the positions of the sound collection holes 13c and the sound collection holes 16c are set as follows.
That is, when the distances between the sound pickup holes 13c and 16c and the reference positions CL11 and CL12 are L13c and L16c, respectively, with the branch cords 11b and 12b straightened, the distance L13c and the distance L16c are substantially equal. It has become.
The distances L13c and L16c are set so that the sound collection holes 13c and 16c are positioned between the ears and the shoulders in a state where the earphone unit 1 is used.

Next, the audio amplification main body 2 will be described in detail.
In FIG. 1, an audio amplification main body 2 includes a resin casing 2a, a circuit board 2b and a power supply section 2c housed in the casing 2a, a power switch 2d that can be slid from the outside, and a power ON It is configured to include an indicator 2e that is sometimes visible from the outside such as an LED, a terminal portion 2f for exchanging signals with the outside, and a volume 2g for volume adjustment. The power supply unit 2c is, for example, an AAA type dry battery or a rechargeable battery.
Further, a clip (not shown) is provided on the back side of the housing 2a (the back side in FIG. 1) so as to be held by a belt or a pocket.

The terminal portion 2f can be connected independently to five signal lines including a pair of output signal lines, a pair of input signal lines, and a common ground line for each signal.
The circuit board 2b is equipped with a known audio signal amplification circuit 2b1 that is turned on / off by the operation of the power switch 2d with the power supply unit 2c as a power source.

  With this audio signal amplification circuit, the audio amplification main body 2 amplifies the input signal coming from the terminal 2f with the amplification factor adjusted by the volume 2g and outputs it as an output signal from the terminal 2f in the power-on state. It is configured as follows.

FIGS. 4A to 4C are diagrams illustrating a state in which the user US who is the user uses the audio amplification system 50 of the embodiment.
4A is a view of the upright user US as viewed from the front, FIG. 4B is a view as viewed from the left hand side, and FIG. 4C is a view as viewed from the rear.

As shown in FIGS. 4A to 4C, the audio amplification system 50 has the earphone main body 11a attached to the right ear, the earphone main body 12a attached to the left ear, and the audio amplification main body 2 attached to the back side. The belt US1 is used while being held by a clip provided on the belt.
At that time, the composite cord 12b1 between the sound collection unit 16 and the branching unit 13 is routed to the rear side of the neck US2 to be attached to the neck.

When the distance L13c and the distance L16c are set to be approximately equal for the earphone unit 1 in this use state, the position of the sound collection hole 16c of the sound collection unit 16 and the position of the sound collection hole 13c of the branch unit 13 are as follows. The left ear EL and the right ear ER are separated from the external auditory canal by approximately the same distance toward the ground.
Therefore, since the speaker is not in the immediate vicinity of the microphone, howling and a peak in the frequency characteristic are less likely to occur. When the distance L13c and the distance 16c are substantially the same distance, the left and right sounds to be collected are actually heard by the ear. Since the sound is collected in a more balanced manner, the sound can be heard with a good sense of reality.

Further, the longer one of the branch cords 11b and 12b has a cord length that is supported on the base or shoulder of the neck while being routed around the back of the neck US2. Yes.
Thereby, even if the microphone 13b is provided in the branch part 13 or the sound collecting part 16 is provided on the branch cord 12b, a part of the increased mass of the microphones 13b, 16b, etc. Can be supported.
Therefore, the earphone unit 1 does not support all of the increased mass with the earphone main body units 11a and 12a in the mounted state.
Therefore, the wearing feeling of the earphone unit 1 is light and good.

Further, since the branch cord 12b is routed around the neck US2 and supported on the root and shoulder of the neck, the positions of the branch cords 11b and 12b and the basic cord 15 with respect to the body are stabilized. .
Therefore, the frequency with which each of the cords 11b, 12b, 15, the branching unit 13, or the sound collecting unit 16 rubs against the clothes is reduced, and it is difficult for the rubbing sound to be generated.
Further, since the branch cord 12b is in contact with the neck and shoulder, even if the cord closer to the plug 14 than the contact position is touched, vibration is favorably absorbed and touch noise is reduced.
In addition, since the position of the sound collection unit 16 does not change greatly, the distance from the mouth is kept substantially constant, and the volume of one's own voice does not vary greatly due to the change in the position of the sound collection unit 16. Is easy to hear.
Therefore, it is possible to suppress the quality deterioration of the listening sound.

Due to the stability of the position, the positions of the sound pickup holes 13c and 16c are also stabilized, and a frequency at which a peak or howling is likely to occur can be specified.
Therefore, when the sound quality correction circuit is mounted on the circuit board 2b, the frequency characteristic can be easily corrected.
Therefore, it is possible to satisfactorily suppress the deterioration of the quality of the listening sound by suppressing the occurrence of peaks and howling.

Further, as shown in FIG. 4B, since the branch cord 12b is routed around the back of the neck US2, the front-rear direction position of the sound collection unit 16 in the use state is the front-rear direction of the ear canal. It is on the rear side [arrow DB side in FIG. 4B] with respect to the reference line CL3 which is the vertical line of the center. The same applies to the branching portion 13, and the position in the front-rear direction is on the rear side with respect to the reference line CL3 that is the vertical line of the front-rear center of the ear canal.
That is, as compared with the case where the branch cords 11b and 12b are worn so as to hang down from the ear to the front side of the body, the positions of the sound pickup holes 13c and 16c are further away from the mouth. It is difficult to pick up sound.
As a result, your voice that does not need to be amplified does not become too loud,
The quality of the listening sound can be maintained satisfactorily.
Even in a state where the face faces downward (a state where the head is inclined forward), since the branch cord 12b is routed around the back of the neck US2, the sound collection unit 16 is Supported by the cord 12b, it is difficult to move to the front of the face against gravity. That is, it is difficult to approach the mouth.
As a result, the sound collecting unit 16 is unlikely to approach the mouth in the state of drooping, so that it is difficult for the own voice to become excessively loud and the quality of the listening sound can be maintained well.

<Other embodiments>
FIG. 5 shows an earphone unit 7 as another embodiment of the stereo earphone of the present invention.
The earphone unit 7 has no branching unit 13 with respect to the earphone unit 1, and a cord from one earphone main body to the other earphone main body unit is derived.

In FIG. 5, an earphone unit 7 includes earphone main body portions 71a and 72a attached to the right and left ears, a cord 72b connecting the earphone main body portion 71a and the earphone main body portion 72a, and an earphone extending from the earphone main body portion 71a. A basic cord 75 having a plug 74 connected to the terminal portion 2f of the sound amplifying main body 2 and two sound collecting portions which are spaced apart from each other on the cord 72b and spaced apart from the earphone main body portions 71a and 72a. 73, 76.
The cord 72b is composed of three parts between the earphone main body 72a and the sound collecting unit 76, between the sound collecting unit 76 and the sound collecting unit 73, and between the sound collecting unit 73 and the earphone main body 71a. These are respectively referred to as a distal end side code portion 72b2, a sound collecting portion code portion 72b1, and a root side cord portion 72b3.

  The earphone main body portions 71a and 72a each incorporate a speaker (not shown in FIG. 5), and can emit sound into the ear canal when the earphone main body portions 71a and 72a are attached to the ears.

As shown in FIGS. 5 and 6, the sound collection unit 76 includes a case 76a and a microphone 76b (see FIG. 6) housed in the internal space V76 thereof. A sound collecting hole 76c is formed as a through hole in the case 76a, and the microphone 76b collects surrounding sound through the sound collecting hole 76c and outputs a sound signal.
Further, as shown in FIG. 3, a sound quality adjusting filter 76d formed of a nonwoven fabric or the like may be disposed between the microphone 76b and the sound collecting hole 76c.

Further, since the sound collecting unit 76 and the sound collecting unit 73 are provided in the middle of the cord 72b, the output supplied from the one end side of the case 76a to the sound collecting unit 73 to the earphone main body 72a. The signal line 72ba and the input signal line 76bb for supplying the audio signal output from the microphone 76b to the plug 74 are combined into a composite code 72b1.
On the other hand, the distal end side cord portion 72b2 from the other end side of the case 76a toward the earphone main body portion 72a is a cord 72b2 having only the output signal line 72ba.

As shown in FIGS. 5 and 7, the sound collection unit 73 includes a resin case 73a and a microphone 73b housed in the internal space V73. A sound collection hole 73c is formed as a through hole in the case 73a, and the microphone 73b collects surrounding sound through the sound collection hole 73c and outputs a sound signal.
The base side cord portion 72b3 extends from one end side (the lower end side in FIG. 7) of the case 73a, and the sound collecting portion cord portion 72b1 extends from the other end side.
As shown in FIG. 7, a sound quality adjusting filter 73d formed of a nonwoven fabric or the like may be disposed between the microphone 73b and the sound pickup hole 73c.

FIG. 8 is a schematic cross-sectional view showing the structure of the earphone main body 71a.
The earphone main body 71a includes a housing 71a1, a bushing 71a2 having two cylindrical portions BS1 and BS2 that are attached to the housing 71a1 and project outward, and a speaker 71a3 housed inside the housing 71a1. Has been.
The housing 71a1 is made of, for example, a synthetic resin material, and the bushing 71a2 is made of, for example, silicone rubber.
A root-side cord portion 72b3 is inserted into the tubular portion BS1, and is folded back inside the housing 71a1 and extends to the outside through the tubular portion BS2.
On the other hand, the output signal line 71ba for supplying output sound to the speaker 71a3 is connected to the speaker 71a3 at the tip side, and is integrated with the root side cord portion 72b3 in the bushing 71a2 and extends to the outside as a basic cord 75.
As shown in FIG. 5, the basic cord 75 is connected to the plug 74 at the distal end side.

In the earphone unit 7 configured as described above, the positions of the sound collection hole 73c and the sound collection hole 76c are set as follows.
That is, as shown in FIG. 5, the reference positions of the earphone main body portions 71a and 72a are set to the reference positions CL71 and CL72 corresponding to the center in the vertical direction of the ear canal when they are attached to the ear, and the distal end side cord portion 72b2 When the distance between the sound pickup holes 73c and 76c and the reference positions CL71 and CL72 is set to L73c and L76c, respectively, with the root side cord portion 72b3 straightened, L73c and L76c are substantially equal. .
The distances L73c and L76c are set so that the sound pickup holes 73c and 76c are located between the ears and the shoulders in a state where the earphone unit 7 is used.
The length of the cord 72b between the earphone main body 71a and the earphone main body 72a is set to a length that allows the earphone main bodies 71a and 72a to be simultaneously attached to the ear by drawing the cord 72b behind the neck.

FIGS. 9A to 9C are diagrams illustrating a state in which the user US is using the audio amplification system 51 including the earphone unit 7 and the audio amplification main body unit 2 which are other embodiments. .
9A is a view of the upright user US as viewed from the front, FIG. 9B is a view as viewed from the left hand side, and FIG. 9C is a view as viewed from the rear.

As shown in FIGS. 9A to 9C, the audio amplification system 51 has the earphone main body 71a attached to the right ear and the earphone main body 72a attached to the left ear, and the audio amplification main body 2 is attached to the back surface thereof. The belt US1 is used while being held by a clip provided on the side.
At that time, the cord 72b that connects between the earphone main body 71a and the earphone main body 72a is routed to the rear side of the neck US2 to be attached to the neck.

In this state of use, when the earphone unit 7 is set so that the distance L73c and the distance L76c are substantially equal, the position of the sound collection hole 76c of the sound collection unit 76 and the position of the sound collection hole 73c of the branch unit 73 Are located at approximately the same distance from the ear canal of the left ear EL and right ear ER toward the ground.
Accordingly, since the speaker is not in the immediate vicinity of the microphone, howling and a peak in the frequency characteristic are less likely to occur. When the distance L73c and the distance 76c are substantially the same distance, the right and left sounds to be collected are actually heard by the ear. Since the sound is collected in a more balanced manner, the sound can be heard with a good sense of reality.

Further, the cord 72b has a cord length that is supported on the root of the neck and the shoulder in a state where the cord 72b is drawn around the back of the neck US2.
Thereby, even if the two sound collection parts 73 and 76 are provided on the cord 72, a part of the mass of the increased microphone or the like can be supported by the neck or shoulder.
Therefore, the earphone unit 7 does not support all of the increased mass with the earphone main body 71a, 72a in the mounted state.
Therefore, the wearing feeling of the earphone unit 7 is light and good.

Further, since the cord 72b is routed around the neck US2 and supported on the neck and the shoulder, the position of the cord 72b with respect to the body is stabilized.
Therefore, the frequency with which the cord 72b and the sound collecting portions 73 and 76 disposed on the cord 72b are rubbed with the clothes is reduced, and the rubbing sound is hardly generated.
In addition, since the sound collecting portions 73 and 76 are provided on the cord 72b, even if a finger touches the basic cord 75, vibrations associated therewith are blocked by the earphone main body 71a, so that touch noise is difficult to be amplified. ing.
In addition, since the positions of the sound collection units 73 and 76 do not change greatly, the distance from the mouth is kept substantially constant, and the volume of one's own voice greatly varies depending on the change in the position of the sound collection units 73 and 76. There is no sound and the listening sound is easier to hear.
Therefore, it is possible to suppress the quality deterioration of the listening sound.

Due to the stability of the position, the positions of the sound pickup holes 73c and 76c are also stabilized, and the frequency at which a peak or howling is likely to occur can be specified.
Therefore, when the sound quality correction circuit is mounted on the circuit board 2b, the frequency characteristic can be easily corrected.
Therefore, it is possible to satisfactorily suppress the deterioration of the quality of the listening sound by suppressing the occurrence of peaks and howling.

Further, as shown in FIG. 9B, since the cord 72b is routed around the back of the neck US2, the face is straight forward (the head is standing upright). The sound collecting portion 73 and the sound collecting portion 76 in the wearing state at the back are both on the rear side with respect to the reference line CL73, which is the vertical line of the front and rear center of the ear canal (arrow DB side in FIG. 9B). It is in.
That is, the cord 72b can be routed around the back of the neck US2, so that the sound collecting holes 73c and 76c are further away from the mouth, making it difficult for the microphones 73b and 76b to pick up their own voice. be able to.
As a result, one's own voice that does not need to be amplified does not become excessively high, and the quality of the listening sound can be maintained satisfactorily.
Even in a state where the face faces downward (a state where the head is inclined obliquely forward), the cord 72b is routed around the back of the neck US2, so that the sound collection unit 73 and the sound collection Both the portions 76 are supported by the cord 72b and are difficult to move in front of the face against gravity. That is, it is difficult to approach the mouth.
As a result, even when the item is drooping, the voice of the user does not become excessively high, and the quality of the listening sound can be maintained extremely well.

  In any of the embodiments, the earphone main body portion attached to one ear is provided at the tip of the cord drawn around the neck by wearing the neck from the other ear side, and one sound collecting portion Is provided in the middle of the cord routed behind the neck, and the other sound collecting part is located in the middle of the cord routed behind the neck or closer to the plug than the branch point of the cord. It is configured.

The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.
In each of the embodiments, the example in which the branch part 13 or the earphone main body part in which the cord 72b extends is described on the right ear side, but these may be on the left ear side.
In each of the embodiments, a description has been given of a configuration having a total of five signal lines that share a common ground line for each input signal from a pair of microphones and each output signal to a pair of speaker units. And 6 signal lines in which the ground lines of the output signal lines are made independent.
Further, it may have eight signal lines in which all the ground lines are made independent.

(Modification)
In each embodiment, the output signal lines 11ba, 12ba, 71ba, 72ba and the input signal lines 13bb, 76bb are described as two-core wires, but the present invention is not limited to this.
For example, the basic cords 15 and 75 are 8-core wires, the branch cord 11b is a 2-core wire, and the branch cord 12b is a 4-core wire between the branch portion 13 and the sound collection portion 16, and the sound collection portion 16 and the earphone main body portion It is good also as a 2 core wire between 12a.
Similarly, for the cord 72b, a 6-core wire is provided between the earphone main body 71a and the sound collection portion 73, a 4-core wire is provided between the sound collection portion 73 and the sound collection portion 76, and the sound collection portion 76 and the earphone main body portion. It is good also as a 2 core wire between 72a.

FIG. 10 is a cross-sectional view for explaining a wiring state inside the sound collection unit 16 in this modification.
In this modification, between the case 16a and the branching section 13, the two core wires S1h and S1c, which are output signal lines supplied to the earphone main body 12a, and the audio signal output from the microphone 16b are directed to the plug 14. The cord S12b1 has four core wires, ie, two core wires S2h and S2c which are input signal lines to be supplied.
Further, a cord S12b2 having only two core wires S1h and S1c as output signal lines is provided between the case 16a and the earphone main body 12a.
Bushings BSG1 and BSG2 are formed at the ends of the cords S12b1 and S12b2, respectively, and are fixed to both ends of the case 16a.
Similarly, the branching unit 13 in the embodiment, and the earphone main body 71a, the sound collecting unit 73, and the sound collecting unit 76 in the other embodiments are also selectively branched with each core wire exposed.

1,7 Earphone part (stereo earphone)
2 Audio amplification body 2a Housing 2b Circuit board 2b1 Amplifying circuit 2c Power supply 2d Power switch 2e Indicator 2f Terminal 2g Volume 11a, 12a, 71a, 72a Earphone body 11b, 12b Branch code 11ba, 12ba, 71ba, 72ba Output Signal line 12b1, 72b1 Composite code 12b2 Single code 13 Branch part 13a, 73a Case 13a1 End part 13b, 73b Microphone 13bb, 76bb Input signal line 13c, 73c Sound collection hole 13d, 73d Filter 14, 74 Plug 15, 75 Basic code 16 , 73, 76 Sound collection unit 16a, 76a Case 16b, 76b Microphone 16bb Input signal line 16c, 76c Sound collection hole 16d, 76d Filter 50, 51 Audio amplification system 71a1 Housing 71a2 Bushing 71a3 Speaker 2b Code 72b1 Sound collecting part code part 72b2 Tip side code part 72b3 Base side code part BS1, BS2 Cylindrical parts CL1, CL2, CL71, CL72 Reference position CL3, CL73 Reference line EL Left ear ER Right ear L13c, L16c, L73c , L76c Distance V13, V16, V73, V76 Internal space

Claims (5)

A plug,
A cord having one end connected to the plug;
Provided on the other end side of the cord, having a first microphone, and branching the cord into a first branch cord and a second branch cord longer than the first branch cord, from the side opposite to the plug A branching portion that extends,
First and second earphone main body portions connected to the respective ends of the first and second branch cords and attached to both ears of the user;
A sound collection unit having a second microphone and provided in the second branch cord;
With
In a state where the cord is positioned on the front side of the user and the first and second earphone main body portions are attached to both ears of the user, the second branch cord is placed on the rear side of the user's neck. A stereo earphone with a length that can be routed.   2. The stereo according to claim 1, wherein a distance between the branch portion and the first earphone main body portion is substantially equal to a distance between the sound collecting portion and the second earphone main body portion. earphone. A plug,
A first cord having one end connected to the plug;
A first earphone body provided on the other end of the first cord;
A second cord having one end connected to the first earphone main body and the other end connected to the second earphone main body;
A first sound collecting unit having a first microphone and a second sound collecting unit having a second microphone, which are provided apart from each other in the second cord;
With
The stereo earphone characterized in that the second cord has a length that allows the first and second earphone main body portions to be simultaneously worn on both ears of a user.   The distance between the first sound collecting unit and the first earphone main body and the distance between the second sound collecting unit and the second earphone main body are substantially equal. The stereo earphone according to claim 3. The stereo earphone according to any one of claims 1 to 4,
An amplifying circuit for amplifying the input audio signal and outputting it as an amplified audio signal; and a terminal portion for connecting the plug so that it can be inserted or removed, or for inputting the audio signal and outputting the amplified audio signal; A sound amplification main body having
A voice amplification system comprising:
The audio signal input to the amplifier circuit is used as the audio signal output from the first and second microphones, and the amplified audio signal output from the amplifier circuit is supplied to the first and second earphone main bodies. An audio amplification system configured to perform

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