JP5548790B1 - Open earphone with sound collecting microphone and hearing aid - Google Patents

Abstract

An earphone and a hearing aid that can prevent howling and allow a user to adjust the frequency characteristics of output sound.
An auxiliary device includes two earphones and a control device having input amplifying means, tone control means, balance adjusting means, and output amplifying means. The earphone 10 includes a housing 11 having an outer surface portion 10a, an inner surface portion 10b, and a peripheral surface portion 10c, a microphone unit disposed in the housing 11, a speaker unit, and a partition wall portion. The peripheral surface portion 10c is formed with an open hole 12 that allows communication between the outside of the housing and the internal space. The partition wall blocks the sound of the speaker unit from entering the microphone unit, and the sound radiated from the opening hole 12 is suppressed from being collected by the microphone unit 13 by the flange 13 and prevents howling. . The open hole 12 increases the sound pressure in the low frequency band of the output sound. The control device 50 can adjust the frequency characteristic and the output level.
[Selection] Figure 1

Description

The present invention relates to an open earphone with a sound collecting microphone and a hearing aid assisting device suitable for a hearing impaired person, particularly a low-frequency hearing person and a middle-tone hearing person.

  As a device to assist hearing-impaired people whose hearing loss has decreased due to aging, disease, trauma, etc., various hearing loss such as hearing aids that are medical devices, sound collectors that do not belong to medical devices, hearing aids, hearing aids, etc. Auxiliary devices have been developed, and in many of these, the speaker part has a structure of an earphone type or a headphone type. In the earphone type, a hook is provided in a housing containing a speaker and the hook is locked to the auricle, an inner ear type in which the housing is pushed into the auricle so as to close the ear canal opening, an ear pad or one of the housings. A canal type in which a part is inserted into the ear canal is known. On the other hand, the headphone type covers the entire auricle with a housing to form a sealed space, the housing covers the entire auricle, but the housing has an open type that has an opening that communicates inside and outside, and the housing is an ear. An on-ear type is known that is attached to the auricle so as to cover a part of the pin, not the entire pin.

It has been pointed out that conventional hearing aids have the following problems.
1) Noise is very strong and many sounds can be heard.
2) Ears get tired when used for a long time.
3) Ears hurt when an impact sound is generated.
4) Sound can be heard, but it is difficult to distinguish words.
5) It is difficult to hear sounds generated far away.
6) In an environment with a high noise level, it is difficult to distinguish human language.
7) Certain sounds may be heard abnormally loud.
8) Sound output from the speaker may be collected again by the microphone to form an acoustic loop, and howling may occur.

  To solve the problem 1, Patent Document 1 discloses a hearing aid circuit that suppresses amplification of signals other than the target signal, efficiently amplifies only the target signal, and can comfortably listen to a desired acoustic signal. The configuration is described.

  Regarding the fatigue of the ear in Problem 2, there are fatigue due to compression by wearing on the ear and auditory fatigue due to long-term listening of sound, and in the case of an earphone type hearing aid, there are differences depending on the structure. . In general, ear-hook type earphones apply external pressure to the ears, but are considered to be less susceptible to sound fatigue. Patent Document 2 describes an earphone device that is worn over a long period of time and does not get tired even when worn for a long time and has little pain due to compression. Although the inner ear type earphone attached to the ear canal has little external pressure on the ear, it is said that the ear canal is easily fatigued by long-term use because it closes the ear canal. The canal type has no external pressure on the pinna but is easily inserted into the ear canal to cause internal pressure to cause fatigue of the ear. In addition, since sound is output in the ear canal, listening fatigue is likely to occur. In order to improve such auditory fatigue, Patent Document 3 discloses hearing aid signal amplification means for amplifying a signal component in a predetermined frequency band, and amplitude / phase compensation means for performing amplitude and phase compensation processing on the signal. A hearing aid is described that uses it to cancel ambient environmental noise and is easy to hear even at low volumes. Furthermore, in Patent Document 4, left and right sound collectors and earphones are housed in separate cases, and the sound collector is attached to a body part other than the auricle, so that it can be used for a long time without feeling tired. A hearing improvement device is described.

  As for the impact sound of the above problem 3, in the case of a normal hearing person, there is no particular concern as long as it is an impact sound generated as a part of a natural sound. When amplified and further using a filter such as noise cancellation, it is transmitted as a more pronounced noticeable impact sound, resulting in an unpleasant sound. For such a problem 3, in Patent Document 5, the input signal is delayed for a certain time by a delay means, and when an impact sound is detected, it is filtered by a filter or connected to another sound source, An impact sound suppression device such as a hearing aid that converts an impact sound into a sound that is easy to hear is described.

  Regarding the above problems 4 to 7, it is disclosed in Patent Document 6 that various listening sounds can be changed to sounds that are easy to hear by flowing an audio signal through a loop coil and receiving a magnetic wave generated from the loop coil by an induction coil. A possible hearing aid is described. Patent Document 7 describes a hearing aid device that filters audio signals generated by microphones provided on the left and right sides of a headphone main body. In Patent Document 8, two large headphones equipped with a receiver and a microphone are connected by an elastic connector, and each headphone is mounted near the outside of the ear canal of both ears, thereby obtaining a good S / N. A hearing aid is described. Patent Document 9 describes an adjuster that can adjust the frequency characteristics of a hearing aid to an optimum state by itself. Furthermore, it has also been proposed to perform noise cancellation and the like to extract and amplify necessary sound by digitally processing an audio signal.

  For the problem 8, Patent Document 10 describes that howling is prevented from occurring in a high-output type earphone with a microphone for a hearing aid for a highly deaf person. In addition, Patent Document 11, Patent Document 12, Patent Document 13, Patent Document 14 and the like have been proposed as a technique for preventing howling in a hearing aid.

JP 09-56000 A JP 2003-111180 A JP 07-264699 A Japanese Patent No. 4190535 Japanese Patent Laid-Open No. 06-276599 Utility Model Registration No. 3103911 Japanese Patent Laid-Open No. 06-233388 JP 09-84196 A Japanese Patent Laid-Open No. 10-126894 JP 2005-286500 A Japanese Patent Laid-Open No. 06-22397 JP 2000-341787 A JP 2002-10397 A JP 2011-49628 A

  Earphones used by hearing-impaired people tend to cause fatigue due to contact and fatigue due to prolonged use. Inner-ear and canal-type earphones inserted into the ear canal not only have pressure on the ear canal, but the sound transmitted to the ear canal is only processed sound that does not include natural sounds, making it easy to feel fatigue it is conceivable that.

  In addition, those having a howling suppression function and a noise canceling function perform digital signal processing, so that they tend to be different from the natural sound heard by the normal hearing person. In particular, hearing aids that use inner-ear or canal-type earphones that block the ear canal are filled with noise and uncomfortable, and the outer ear canal must be sealed. There is a problem that is difficult to use for a long time. Therefore, it is considered that the earphones that do not block the ear canal have less pressure on the ears and listen to natural sounds at the same time, so that there is less auditory fatigue. It is desirable that suppression of howling can be dealt with structurally, not electrically.

  In addition, hearing aids may be required to compensate for overall hearing loss due to aging or chronic otitis media. In this case, a device whose frequency characteristics are adjusted in advance according to the hearing loss level of each user is provided, but it is not always satisfied with the user.

  Furthermore, for the purpose of suppressing howling, it has been proposed to produce a microphone for collecting sound separately from the earphones to be worn on the ear. In this case, it is possible to use a telephone handset or a mobile phone device. When a call is made, the sound is heard at a position different from the position of the ear, so that there is a problem that the call operation becomes unnatural and the user feels uncomfortable.

  In the techniques described in Patent Documents 1 to 14 described above, an open-type earphone that does not block the ear canal such as an ear hook type, in which a microphone unit and a speaker unit are incorporated in one housing, It is difficult to reliably prevent howling without using processing. In addition, there is no description that the user can individually adjust the frequency characteristics of the output sound.

In view of such conventional problems, the present invention can compensate for hearing loss and output high quality sound close to natural sound, and reliably prevent howling without using digital processing. An object of the present invention is to provide an open earphone with a sound collecting microphone and a hearing aid.

The present invention is a housing that is mounted so as to be in contact with a person's auricle and has at least an inner surface facing the ear canal and an outer surface facing the inner surface, the inner surface having a size larger than the hole diameter of the ear canal. A large housing, a microphone unit disposed in the housing and positioned in the vicinity of the outer surface portion, and collecting external sounds, and disposed in the housing and in the vicinity of the inner surface portion. A speaker unit that outputs a sound collected by the microphone unit; and a space provided around the speaker unit to define a space between the speaker unit and the microphone unit. Including partition walls
An opening hole is formed in the housing to allow communication between the outside of the housing and the space around the speaker unit.
When the housing is mounted on the human auricle, the open hole is located outside the auricle as viewed from the center of the human head, and the penetration direction is a virtual contact with the auricle of the auricle. direction der nearly parallel or parallel to the plane is,
The housing further includes a peripheral surface portion sandwiched between the inner surface portion and the outer surface portion,
A collar part provided on the surface of the peripheral surface part so as to protrude outward from the position between the open hole and the external surface part, and is equivalent to or larger than the auricle It is an open type earphone with a sound collection microphone characterized by having .

The present invention also provides an open earphone with a sound collecting microphone, and
A control device electrically connected to the open earphone with the sound collecting microphone,
Amplifying means for input for amplifying an audio signal input from the microphone unit;
The audio signal amplified by the input amplification means is adjusted so that a signal output level at a predetermined reference frequency is constant, and a low frequency band having a frequency lower than the reference frequency in the audio signal and the reference frequency Tone control means that can adjust the frequency characteristics of the high frequency band with higher frequency than
The hearing aid according to claim 1, further comprising: a control device having an output amplifying means for amplifying an audio signal whose frequency characteristic is adjusted by the tone control means and outputting the amplified signal to the speaker unit.

Further, the present invention provides two open earphones with a sound collecting microphone, and
A control device electrically connected to the two open earphones with sound collecting microphones,
Input amplifying means for independently amplifying each audio signal input from each microphone unit of the open type earphone with two sound collecting microphones;
The two audio signals amplified by the input amplifying means are independently adjusted so that the signal output level at a predetermined reference frequency is constant, and the frequency is lower than the reference frequency in each audio signal. Tone control means capable of adjusting the frequency characteristics of the frequency band and the high frequency band having a frequency higher than the reference frequency, respectively;
Balance adjusting means for adjusting the output levels of the two audio signals whose frequency characteristics are adjusted by the tone control means;
A control device having output amplifying means for amplifying the two audio signals adjusted by the balance adjusting means and outputting them to the respective speaker units of the two earphones with sound collecting microphones; Auxiliary equipment.

  In the hearing aid according to the present invention, the reference frequency is a predetermined frequency in a range of 2000 to 4000 Hz.

According to the open-type earphone with a sound collecting microphone according to the present invention (hereinafter simply referred to as “earphone”), sound output from the speaker unit is incident on the microphone unit by the partition provided in the housing. To prevent. In addition, when the housing is mounted on the human auricle, an open hole that allows communication between the outside of the housing and the space around the speaker unit is located outside the auricle as viewed from the center of the human head. Since the housing is formed so that the penetrating direction is parallel or nearly parallel to the virtual plane in contact with the pinna, the sound emitted from the open hole is reflected by the pinna, and the microphone unit The collected sound is suppressed. Therefore, it is possible to prevent the occurrence of howling due to the sound output from the speaker unit being collected by the microphone unit, and to form an earphone structure with a high gain.

  In addition, by forming an open hole in the housing so that the internal space of the housing communicates with the outside, the sound pressure in the low frequency band of the sound output from the speaker unit can be increased. Therefore, an earphone excellent in low sound reproduction can be provided.

  Moreover, since the atmospheric pressure inside the housing can be made equal to the external atmospheric pressure by forming the open hole, the change in the acoustic characteristics due to the pressure difference can be eliminated. Furthermore, since the internal temperature of the housing is equal to the outside air temperature, changes in expansion and contraction of the diaphragm due to temperature changes can be reduced, and changes in frequency characteristics due to volume changes can be suppressed.

  In addition, according to the earphone according to the present invention, the size of the inner surface portion of the housing is set larger than the hole diameter of the ear canal, so that the ear canal is not blocked, so there is less pressure during use and the device can be used for a long time. A suitable earphone can be provided.

Further, according to the earphone of the present invention, the front surface of the peripheral surface portion of the housing is a flange portion protruding outward from the peripheral surface portion from a position between the open hole and the outer surface portion, and is equivalent to the auricle or auricle. Since the larger collar portion is provided, it is possible to prevent the sound emitted from the open hole from being reflected and collected by the microphone.

  According to the hearing aid according to the present invention, the earphone is provided with a control device having an input amplifying means, a tone control means, and an output amplifying means, so that the microphone unit collects the sound from the speaker unit. The user can adjust the frequency characteristics of the output sound as desired by the user.

  According to the hearing aid according to the present invention, since the two earphones are provided with a control device having an input amplification means, a tone control means, a balance adjustment means, and an output amplification means, the left and right microphone units The user can adjust the frequency characteristics and the output level of the sound collected by each and output from the left and right speaker units independently on the left and right sides as desired by the user.

  Further, according to the hearing aid according to the present invention, since the reference frequency is based on the frequency band with the highest human hearing sensitivity in the range of 2000 to 4000 Hz, there is little individual difference, and thus one reference frequency is set. Can be used in common.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the hearing aid 1 according to the first embodiment of the present invention with a part omitted. BRIEF DESCRIPTION OF THE DRAWINGS The earphone 10 which concerns on the 1st Embodiment of this invention is shown, Comprising: It is a front view of the outer surface part 10a. It is sectional drawing in the BB line of FIG. 2A. It is sectional drawing in the CC line of FIG. 2A. It is sectional drawing which shows the speaker unit 30 used for the earphone 10 which concerns on the 1st Embodiment of this invention. It is a block diagram which shows roughly the internal structure of the auxiliary device for hearing loss 1 which concerns on the 1st Embodiment of this invention. It is a graph which shows a loudness curve, Comprising: A sound pressure level (dB) is shown on a vertical axis | shaft, and a frequency (Hz) is shown on a horizontal axis | shaft. It is a graph which shows the audiogram according to age (Excerpt from “Calculation formula of hearing deterioration due to aging” of Audiology Japan 46, 2003), with the vertical axis indicating the hearing loss level (dB) and the horizontal axis indicating the frequency (Hz). Is. It is a graph which shows the frequency characteristic adjusted with the control apparatus 50, Comprising: An output level (dB) is shown on a vertical axis | shaft, and a frequency (Hz) is shown on a horizontal axis | shaft. It is a flowchart explaining operation | movement of the auxiliary device for hearing loss 1 which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows typically the state with which the earphone 10 which concerns on the 1st Embodiment of this invention was mounted | worn with the human pinna E. FIG. It is sectional drawing which shows another aspect of the earphone 10 which concerns on the 1st Embodiment of this invention, Comprising: The state with which the human ear pinion E was mounted | worn typically is shown. The earphone 10 which concerns on the 2nd Embodiment of this invention is shown, Comprising: It is a front view of the outer surface part 10a. It is sectional drawing in the B2-B2 line | wire of FIG. 11A. It is sectional drawing in the C2-C2 line | wire of FIG. 11A.

(First embodiment)
FIG. 1 is a perspective view showing the hearing aid 1 according to the first embodiment of the present invention with a part thereof omitted, and FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A, FIG. 2C is a cross-sectional view taken along the line CC in FIG. 2A, and FIG. 3 is a cross-sectional view showing the speaker unit 30 used in the earphone 10. Is a block diagram schematically showing the internal configuration of the hearing aid 1, FIG. 5 is a graph showing a loudness curve, FIG. 6 is a graph showing an audiogram by age, and FIG. 7 is adjusted by the control device 50. FIG. 8 is a flowchart for explaining the operation of the hearing aid 1 according to the first embodiment of the present invention, and FIG. 9 shows the earphone 10 according to the first embodiment of the present invention. , Schematic of the state of wearing on the human pinna E Cross-sectional view illustrating, FIG. 10, there is shown another embodiment of the earphone 10 according to the first embodiment of the present invention, it is a cross-sectional view showing a state of mounting the auricle E of the human schematically.

  In the following description, front / rear, left / right, and upper / lower refer to front / rear, left / right, and upper / lower with reference to the human body with the earphone 10 attached to the human ear E.

  The hearing aid 1 according to this embodiment is mainly intended for low-frequency hearing loss and middle-range hearing loss such as hearing loss due to aging and hearing loss due to chronic otitis media. It is also applicable to.

  As shown in FIG. 1, the hearing aid 1 according to the present embodiment includes two earphones 10 and a control device 50 that is electrically connected to the earphones 10. As for the two earphones 10, one 10R is for the right ear and the other 10L is for the left ear.

  In the present embodiment, the two earphones 10 and the control device 50 are connected by a signal cable 40. The signal cable 40 includes a branch cable 41 connected to each of the two earphones 10, an integrated unit 42 that combines the two branch cables 41, an integrated cable 43 that combines the branch cables into one, and an integrated cable. And a connector portion 44 provided at the end of 43. By inserting the connector 44 into the earphone jack 54 of the control device 50, the earphone 10 and the control device 50 are electrically connected. The earphone 10 and the control device 50 can be connected so that signals can be transmitted wirelessly. For example, Bluetooth (registered trademark) that has no directivity and is resistant to interference can be used.

  An earphone 10 shown as an example of this embodiment in FIGS. 2A to 2C is an ear hook type having a hook 14, and includes a microphone unit 20 and a speaker unit 30 incorporated in a substantially hollow cylindrical housing 11. . The housing 11 is formed by combining an outer portion 11a forming an outer surface portion 10a, an inner portion 11b forming an inner surface portion 10b, and an intermediate portion 11c forming a peripheral surface portion 10c sandwiched between the outer surface portion 10a and the inner surface portion 10b. A hollow space S is formed in the housing 11 between the microphone unit 20 and the speaker unit 30. The housing 11 is made of a resin member such as ABS (acrylonitrile-butadiene-styrene), PS-HI (polystyrene-high impact), PC (polycarbonate). Note that at least the inner surface portion 10b in contact with the auricle is made larger in size than the hole diameter of the human external auditory canal G (see FIG. 9). Since the hole diameter of the ear canal G is generally less than 10 mm, the outer diameter of the inner surface portion 10 b may be set to 10 mm or more.

  A support member 17 that supports the microphone unit 20 is attached to the outer portion 11a at the opening in the center. The support member 17 supports the microphone unit 20 so that the sound collection surface 20a for collecting external sound faces the outside of the housing 11, and the side surface and the back surface of the microphone unit 20 excluding the sound collection surface 20a. Covering. A microphone cover 15 that covers the sound collection surface 20 a of the microphone unit 20 is attached to the center of the support member 17. The microphone cover 15 is provided with slits and holes so that the microphone unit 20 can easily collect external sounds.

  The microphone unit 20 is preferably omnidirectional and highly sensitive so as to collect natural sounds, and for example, a back electret condenser microphone is used. As a specific example, a Panasonic non-directional microphone unit WM-61A (microphone sensitivity -35 dB (0 dB = 1 V / Pa, 1 kHz)) is used. Although illustration is omitted, an elastic member may be provided around the microphone unit 20 to prevent vibration.

  The inner portion 11b of the housing 11 has a support portion 19 that supports the speaker unit 30 so that the diaphragm 35 that outputs sound faces the ear canal. A through hole 18 for efficiently transmitting the sound output from the speaker unit 30 into the external auditory canal is formed in a portion forming the inner surface part 10 b in the inner part 11 b, and further, a net-like shape is formed so as to cover the through hole 18. A speaker cover 16 having a lattice shape or a porous shape is attached.

  The speaker unit 30 includes a dynamic type, a balanced armature type, and the like, and it is preferable to use a dynamic type in the earphone 10 of the ear-mounted type as in this embodiment. As shown in FIG. 3, the speaker unit 30 is provided with a yoke 33 with a magnet 32 in the center of the frame 31 and a vibration plate 35 so as to cover one surface of the frame 31. The coil 34 attached to the back side of the plate 35 is disposed in the gap between the frame 31 and the yoke 33. A material made of a resin film having a light mass is used for the diaphragm 35, for example, polyetherimide. The diaphragm 35 is driven by passing a current through the coil 34 placed in the magnetic field formed by the magnet 32. In the present embodiment, a vent hole 36 that connects the space S around the speaker unit 30 and the space on the back side of the diaphragm 35 is formed in a part of the frame 31. Further, a ventilation resistor 37 that restricts the flow of air passing through the ventilation hole 36 is attached to the surface of the frame 31. As the ventilation resistor 37, it is preferable to use a non-woven fabric having air permeability such as cotton or polyester fiber.

  In the example of the present embodiment, the center of the microphone unit 20 is located at the center of the outer surface portion 10a, the center of the speaker unit 30 is located at the center of the inner surface portion 10b, and the center axis of the microphone unit 20 and the speaker unit 30 are The central axis is arranged so as to be coaxial. Therefore, the sound collection surface 20a of the microphone unit 20 and the diaphragm 35 of the speaker unit 30 are in a positional relationship facing each other. With this configuration, when the user who wears the earphone 10 on the auricle E makes a call using the handset or the mobile phone device of the telephone, the handset is pressed by pressing the handset or the mobile phone device against the auricle. In addition, the receiving speaker portion of the mobile phone device can be naturally faced to the part facing the microphone unit 20. Therefore, it is possible to perform a call operation using the telephone or the mobile phone device without feeling uncomfortable while wearing the earphone 10.

  In the example of the present embodiment, the support member 17 that supports the microphone unit 20 is a partition wall that partitions the microphone unit 20 and the speaker unit 30, and the sound output from the speaker unit 30 is a space. Direct transmission to the microphone unit 20 through S is prevented.

  The intermediate part 11c that forms the peripheral surface part 10c of the housing 11 is a member that is sandwiched and held between the outer part 11a and the inner part 11b, and is an open hole that allows communication between the outside of the housing 11 and the internal space S. 12 is formed. The open hole 12 of the present embodiment is a long and narrow rectangular slit, which is formed so as to face the front side portion and the rear side portion of the peripheral surface portion 10c. However, only one slit may be formed, and the formation position is also It can be changed. Alternatively, a structure in which one or a plurality of holes having a circular opening shape are provided to form the open holes 12 is also possible. In order to prevent the inside from being contaminated by intrusion of dust or the like, a non-woven fabric having air permeability may be attached to the slit.

  The volume of the space S of the housing 11 and the total opening area of the open holes 12 are preferably determined so that the acoustic characteristics are optimal. The space S facing the back surface of the speaker unit 30 has the effect of improving the sound quality in the low frequency band by resonating and enhancing the vibration in the low frequency band. Accordingly, by appropriately setting the volume of the space S and the total opening area of the open hole 12 for the space S, a space S suitable for the acoustic characteristics of the speaker unit 30 is formed, and the reproducibility of the sound in the low frequency band is improved. improves. Further, when air flows through the open hole 12, the air pressure in the space S and the air pressure outside the housing 11 become equal, and the air temperature in the space S can be made equal to the outside air temperature. Therefore, it is possible to prevent the acoustic characteristics from fluctuating by changing the frequency characteristics due to the pressure difference between the inside and outside of the housing 11 or expanding and contracting the diaphragm 35 of the speaker unit 30 due to the temperature difference.

  On the surface of the intermediate portion 11 c of the housing 11, a flange portion 13 that protrudes outward from the peripheral surface portion 10 c from a position between the open hole 12 and the outer surface portion 10 a is provided. In the present embodiment, the collar portion 13 is disposed in the immediate vicinity of the opening hole 12, but may be appropriately separated from the opening hole 12. The flange 13 prevents the sound output from the speaker unit 30 and radiated from the open hole 12 through the space S from being reflected by the auricle and collected by the microphone unit 20. For this reason, it is desirable that the heel part 13 is equal to or larger than the auricle.

  Further, a hook attachment portion 11d for attaching a hook 14 to be locked to the auricle is provided integrally with the intermediate portion 11c in order to attach the housing 11 to a human ear. As an example of the hook 14, one having a form that is curved so as to conform to the shape of an average pinna can be considered. The hook attachment portion 11d has an attachment hole 11e through which the base portion 14a of the hook 14 is rotatably inserted. By rotating the hook 14 by an appropriate angle, the earphone 10 can be held in contact with the auricle. Note that the earphone 10 is configured to be a headband type, a neckband type, or a clip type.

  In the earphone 10 of the present embodiment, a space S facing the speaker unit 30 inside the housing 11 and the microphone unit 20 are partitioned by a support member 17 that is a partition wall. Thereby, the sound output from the back surface of the speaker unit 30 is prevented from being directly transmitted to the microphone unit.

  Since the earphone 10 of the present embodiment is an open type in which the housing 11 is formed larger than the hole diameter of the ear canal G, external natural sounds can be heard at the same time, and compression into the ear canal is small. Can reduce ear fatigue. In addition, the conventional canal type earphone may cause a volume change of the ear canal depending on the insertion state in the ear canal, and may significantly change the frequency characteristic to deteriorate the sound quality. Since it is an open type, the volume of the ear canal does not change, and therefore the frequency characteristics do not change.

  Since the earphone 10 of the present embodiment employs an open type that does not block the ear canal, the housing 11 is larger than the inner ear type or canal type earphone, and the area of the diaphragm 35 of the speaker unit 30 can be increased. Therefore, a large sound pressure can be obtained. Since the sound pressure of the sound in the frequency band of 2 KHz or higher is proportional to the square of the radius of the diaphragm 35, the larger the diaphragm 35, the more advantageous the speaker unit 30 for reproducing high-frequency sounds. Since the earphone 10 of the present embodiment is an open type with a large housing 11, it can output larger from a low sound region to a high sound region than an inner ear type or canal type earphone.

  The control device 50 is electrically connected to the earphone 10, and has a built-in control circuit that processes an audio signal generated by the microphone unit 20 collecting sound and outputs the processed signal to the speaker unit 30. As shown in FIG. 1, the case 51 is turned on when the power source is turned on, and a rotary volume control switch 52 that performs ON / OFF switching of the power source of the control device 50 and adjustment of the output volume to the earphone 10. A power lamp 53, an earphone jack 54 into which the connector portion 44 of the earphone 10 is inserted, a treble adjuster 55 for adjusting the frequency characteristics of a high frequency band described later, a bass adjuster 56 for adjusting the frequency characteristics of the low frequency band, A balance adjustment unit 57 that adjusts the output volume to the left and right earphones 10L, 10R is provided.

  As shown in the block diagram of FIG. 4, the control circuit built in the case 51 includes an input amplifier circuit 61 that amplifies the left and right audio signals input from the left and right microphone units 20, respectively, and the amplified left and right audio signals. Frequency characteristic adjustment circuit 62 for adjusting the frequency characteristic of the audio signal, balance adjustment circuit 63 for adjusting the output level of the left and right audio signals whose frequency characteristics are adjusted, and output for amplifying the left and right audio signals whose output levels have been adjusted An amplifier circuit 64 is provided. The frequency characteristic adjustment circuit 62 and the balance adjustment circuit 63 are connected to an operation unit 70 that is interlocked with the treble adjustment unit 55, the bass adjustment unit 56, and the balance adjustment unit 57 provided in the case 51. The input amplifier circuit 61 corresponds to the input amplifier means, the frequency characteristic adjustment circuit 62 and the operation unit 70 correspond to the tone control means, the balance adjustment circuit 63 and the operation section 70 correspond to the balance adjustment means, and the output The amplifier circuit 64 corresponds to output amplifier means.

  For the input amplifier circuit 61 and the output amplifier circuit 64, for example, a negative feedback amplifier circuit using an operational amplifier is used. By using a negative feedback amplifier circuit, it is possible to stabilize the amplification process of the input signal and stabilize the amplification process of the audio signal at the time of output.

  The frequency characteristic adjusting circuit 62 uses a predetermined frequency as a reference frequency, adjusts the output level of the reference frequency in the input audio signal to be constant, and lowers the frequency than the reference frequency in each audio signal. And adjusting the frequency characteristics of the high frequency band whose frequency is higher than the reference frequency to form the desired frequency characteristics. In the present embodiment, the reference frequency is 3500 Hz, and the frequency characteristics of the low frequency band lower than 3500 Hz and the frequency characteristics of the high frequency band higher than 3500 Hz can be adjusted using the variable resistor.

  The reference frequency is preferably determined in the range of 1000 Hz to 4000 Hz, more preferably 2500 Hz to 3500 Hz. This setting is based on the fact that the resonance frequency of the space in the human ear canal exists between 2000 Hz and 4000 Hz. Further, it can be understood from the loudness curve shown in FIG. 5 that the frequency range of 1000 Hz to 4000 Hz is a frequency band in which a person has the highest hearing sensitivity. Therefore, by setting the frequency of this frequency band as a reference frequency, it becomes possible to use one reference frequency as standard for any person, and it becomes unnecessary to change the value of the reference frequency by an individual. Therefore, each individual only needs to adjust the frequency characteristic according to the degree of hearing loss, and can provide a hearing aid auxiliary device that can be adjusted by the individual.

  FIG. 6 shows an audiogram by age (extracted from “Calculation formula of hearing deterioration due to aging” of Audiology Japan 46, 2003). As shown in the graph of FIG. 6, hearing decreases with aging. On the other hand, as shown in the loudness curve of FIG. 5, the ear sensitivity is high in the range of 1000 Hz to 4000 Hz, and the sensitivity is poor before and after the frequency. In view of such a situation, the present embodiment is configured as a hearing aid auxiliary device that adjusts the frequency characteristics as follows to obtain sound pressure in a low frequency region and a high frequency region.

  In the present embodiment, the frequency characteristics are adjusted in the manner illustrated in FIG. In FIG. 7, a curve P indicates an upper limit value when the frequency characteristic is adjusted, a straight line R indicates a lower limit value when the frequency characteristic is adjusted, and a curve Q indicates a practical upper limit value when the frequency characteristic is adjusted. Show. As shown by the curve P, the upper limit value when adjusting the frequency characteristic is, for example, a value adjusted by -6 dB / oct for the low frequency band lower than the reference frequency when the output level of the reference frequency (3.5 kHz) is 0 dB. (A value increased by 6 dB every time the frequency is halved), and for a high frequency band higher than the reference frequency, a value adjusted by 6 dB / oct (increased by 6 dB every time the frequency is doubled) Value). The lower limit when adjusting the frequency characteristic is set to 0 dB, which is equal to the output level of the reference frequency (3.5 kHz), as indicated by the straight line R. Therefore, in the present embodiment, the frequency characteristic is adjusted within a range sandwiched between the curve P and the straight line R. However, as indicated by the curve Q, the practical upper limit value can be uniformly set to +12 dB for the frequency band of 875 Hz or lower, and can be set to +6 dB for the frequency band of 7000 Hz or higher. The frequency characteristic adjusting circuit 62 in the present embodiment uses, for example, an analog circuit and uses 3.5 kHz as a reference frequency, and is -6 dB / oct at the maximum in the frequency band below the reference frequency, and 6 dB / oct at the maximum in the frequency band above the reference frequency. Thus, it can be considered that the output level can be varied.

  The hearing aid 1 according to the present embodiment configured as described above executes the processing shown in FIG. The earphones 10 are attached to the left and right ears, and the volume control switch 52 of the control device 50 is rotated to turn on the power. In this state, when the left and right microphone units 20 collect external sound in step S1, the microphone unit 20 converts the collected left and right sounds into electrical audio signals in step S2, and the control device 50 Output to. When the left and right audio signals are input to the input amplifier circuit 61 of the control device 50 in step S3, the input amplifier circuit 61 independently amplifies the left and right audio signals in step S4 to adjust the frequency characteristics. Output to the circuit 62.

  In step S5, the frequency characteristic adjusting circuit 62 adjusts the output level at the reference frequency of the input audio signal to a predetermined constant value. As a specific example, an output level of 3500 Hz is set to 0 dB. Next, in step S6, the frequency characteristic of the low frequency band lower than the reference frequency is adjusted based on, for example, the frequency characteristic curve shown in FIG. Similarly, in step S7, the frequency characteristic in the high frequency band higher than the reference frequency is adjusted based on, for example, the frequency characteristic curve shown in FIG. The adjustment operation in step S6 can be performed by operating the bass adjustment unit 56 provided in the control device 50. The adjustment operation in step S7 can be performed by operating the treble adjustment unit 55. Therefore, it is possible for the user to freely set how much the output level of the sound in the lower frequency band or the higher frequency band than the reference frequency is increased according to the degree of hearing loss. In this embodiment, the common frequency characteristic is applied to the left and right audio signals. However, it is also possible to apply a desired frequency characteristic independently to the left and right audio signals.

  Subsequently, in step S8, the output levels of the left and right audio signals are adjusted by the balance adjustment circuit 63 that is linked to the balance adjustment unit 57. In step S9, the left and right audio signals that have been adjusted in balance are output to the output amplifier circuit 64. In step S10, the signal is output to the left and right speaker units 30. The left and right speaker units 30 convert an input audio signal into audio and output it to the outside.

  As described above, the hearing aid 1 according to the present embodiment can adjust the frequency characteristics of the sound to be output by the control device 50. Therefore, the user adjusts the hearing aid most easily according to the individual deafness state. Audio can be output. In addition, since the earphone 10 according to the present embodiment can use the speaker unit 30 having a diameter larger than that of the external auditory canal, the diaphragm 35 can be enlarged, and the open hole 12 is formed in the housing 11, and the speaker unit 30. By making the space S formed on the back side of the space and the outside communicate with each other, the vibration in the low frequency region due to the space S can be resonated and enhanced. Therefore, since it has a structure that is excellent in low-pitched sound reproduction characteristics and can obtain a large sound pressure, it is possible to provide the hearing aid auxiliary device 1 that is useful for low- and low-hearing persons.

  FIG. 9 is a cross-sectional view schematically showing a state in which the earphone 10 is mounted on the human auricle E. As shown in the figure, since the outer diameter of the earphone 10 is larger than the hole diameter of the ear canal G, when the housing 11 is attached to the auricle E, the speaker cover 16 attached to the inner surface portion 10b is attached to the ear canal F. The outer surface portion 10a of the housing 11 is located outside the auricle E. In the present embodiment, in the state where the housing 11 is attached to the auricle E, the position of the open hole 12 formed in the peripheral surface portion 10c is more than the portion outside the auricle E as viewed from the center of the human head. Is set to be further outside. In order to securely position the opening hole 12 outside the pinna E, it is more desirable to make the size of the earphone 10 approximate to the pinna. Further, as shown in FIG. 9, the penetration direction of the open hole 12 provided in the peripheral surface portion 10 c is parallel or nearly parallel to the virtual plane K in contact with the ear ring of the pinna E.

  Since the opening 12 is configured in this way, the sound output from the speaker unit 30 and radiated to the outside through the opening 12 is reduced by being reflected by the pinna E and entering the microphone unit 20. Since howling is suppressed, the earphone structure has a high gain.

  When the opening hole 12 is formed at a position closer to the inner surface portion 10b than the outermost part of the pinna E, the opening hole may be closed by contact with the ear. When the opening hole is closed, there is a difference between the air pressure inside the earphone and the outside air pressure, and there is also a difference between the internal temperature and the outside air temperature. As a result, the frequency characteristics may change, making it impossible to obtain good sound quality. There is sex.

  When the open hole 12 is formed not on the peripheral surface portion 10c but on the outer surface portion 10a, when a user who wears the earphone 10 on the auricle E makes a call using a telephone or a mobile phone device The sound output from the speaker unit 30 and radiated from the open hole 12 is reflected by the handset or the cellular phone device pressed against the outer surface portion 10a of the housing 11 and enters the microphone unit 20 to form an acoustic loop. It becomes easy to cause howling.

  In the present embodiment, a flange 13 that protrudes outward from the peripheral surface portion 10c is further provided on the surface of the peripheral surface portion 10c at a position between the open hole 12 and the outer surface portion 10a. In this embodiment, the flange portion 13 is provided in the immediate vicinity of the open hole 12. However, the flange portion 13 may be separated from the open hole 12, and may be between the open hole 12 and the outer surface portion 10a in the peripheral surface portion 10c. There is no particular limitation. The flange 13 reflects the sound radiated from the open hole 12 and prevents it from entering the microphone unit 20, thereby improving the howling prevention effect and providing the earphone 10 with high gain. can do.

  As shown in FIG. 10, an ear pad 38 that surrounds the outer periphery of the speaker cover 16 and abuts on the surface of the pinna E may be provided on the inner surface 10 b of the housing 11. The effect which suppresses that the sound output to outside leaks out is exhibited. Further, the ear pad 38 can improve the feeling of wearing the housing 11 with respect to the pinna E. For this purpose, it is preferable that the ear pad 38 is made of a material having good sound insulation and softness against the pinna E, and having flexibility.

(Second Embodiment)
11A shows the earphone 10 according to the second embodiment of the present invention, and is a front view of the outer surface portion 10a, FIG. 11B is a sectional view taken along line B2-B2 of FIG. 11A, and FIG. 11C is FIG. It is sectional drawing in the C2-C2 line.

  In the earphone 10 of the present embodiment, the microphone unit 20 is disposed on the front side of the housing 11, and the positions where the opening holes 12 are formed are the upper part and the lower part of the peripheral surface part 10 c. The diameter is enlarged according to the size of the microphone cover 15 that covers the sound collection surface 20 a of the microphone unit 20.

  In the present embodiment, a bottomed cylindrical support portion 11f is provided on the front portion of the peripheral surface portion 10c so as to protrude from the surface, and the sound collection surface 20a of the microphone unit 20 is the same as the outer surface portion 10a. And the sound collection surface 20a is covered with the microphone cover 15. A part of the peripheral surface part 10c constituting a part of the support part 11f is a partition part 21 that partitions the microphone unit 20 and the space S.

  According to this configuration, the position where the opening hole 12 is formed and the position of the sound collection surface 20a of the microphone unit 20 are separated from each other, so that sound radiated from the opening hole 12 is difficult to enter the microphone unit 20. Therefore, since an acoustic loop hardly occurs, howling can be suppressed and a high gain configuration can be achieved.

  In the present embodiment, since the microphone unit 20 is positioned almost inside the pinna, the sound generated in front of the user has a difference in the arrival time between the sound heard by the ear and the sound collected by the microphone unit 20. For this reason, after the sound collected by the microphone unit 20 is processed by the control device 50, the uncomfortable feeling based on the time difference required to output from the speaker unit 30 can be reduced.

  As described above, since the hearing aid 1 according to the first and second embodiments has the configuration of the open earphone 10, there is little change in frequency characteristics based on individual differences in the shape of the ear, Less fatigue of ears due to prolonged use. Since the housing 11 is an open type and is formed to be larger than the hole diameter of the ear canal, it is not necessary to match the form of the user's individual ear canal, and since the ear canal is not blocked, sounds close to natural can be heard. Since the outer diameter of the housing 11 is larger than that of the inner ear type or the canal type, the diameter of the diaphragm 35 of the speaker unit 30 can be increased, and the opening hole 12 can stabilize the environment in the housing 11. Because of the improvement in bass reproducibility, it is possible to listen to the sound from low to high frequencies stably. Especially, the sound pressure in the low frequency band should be larger than the inner ear type or canal type. Can do.

  In the housing 11, a partition wall that partitions the microphone unit 20 and the speaker unit 30 is provided to prevent sound output from the speaker unit 30 from being directly transmitted to the microphone 20 through the space S. ing. In addition, the opening hole 12 is provided in the peripheral surface portion 10c and the flange portion 13 is provided to prevent the microphone 20 from collecting the sound emitted from the opening hole 12. Therefore, howling can be reliably prevented while the microphone unit 20 and the speaker unit 30 are assembled in the single housing 11.

  Further, when making a call using a handset or a mobile phone device of a telephone, the occurrence of howling by forming an acoustic loop between the handset or the mobile phone device and the earphone 10 is suppressed and avoided. .

  In the first and second embodiments, the input amplifier circuit 61 and the output amplifier circuit 64 of the control device 50 are both constituted by analog circuits using operational amplifiers, and a negative feedback circuit is used. Stabilize the amplification process of the audio signal input from the microphone unit 20, stabilize the amplification of the audio signal output to the speaker unit 30, and approximate the sound output from the speaker unit 30 to a natural sound. Yes.

  Since the output level of the reference frequency of the audio signal is adjusted to be constant and the frequency characteristics of the low frequency band and high frequency band region can be adjusted with reference to the reference frequency, the user can adjust to the individual deafness level. Since the frequency characteristics of the output sound can be adjusted arbitrarily, the collected external sound can be heard as a sound close to nature.

  Further, since the balance adjustment circuit 63 for adjusting the output level of the sound output from the speaker unit 30 of each of the two earphones 10 for the left and right ears is provided, users with different deafness levels of the left and right ears have a hearing level. It is possible to listen equally to the left and right.

DESCRIPTION OF SYMBOLS 1 Auxiliary device for hearing loss 10 Ear fin 10a with a sound collection microphone Outer surface part 10b Inner surface part 10c Peripheral surface part 11 Housing 12 Opening hole 13 Gutter part 14 Hook 20 Microphone unit 20a Sound collection surface 30 Speaker unit 35 Diaphragm 40 Signal cable 50 Control device 52 Volume control switch 52
55 Treble adjustment part 55
56 Bass Adjustment Unit 57 Balance Adjustment Unit 57
61 Amplifying circuit for input 62 Frequency adjusting circuit 63 Balance adjusting circuit 64 Amplifying circuit for output 70 Operation part E Pinna F Ear canal G Ear canal S Space

Claims (4)

A housing that is mounted so as to be in contact with a person's pinna and has at least an inner surface facing the ear canal and an outer surface facing the inner surface, the inner surface having a size larger than the hole diameter of the ear canal; A microphone unit disposed in the housing and located in the vicinity of the outer surface portion and collecting external sound; and a microphone unit disposed in the housing and located in the vicinity of the inner surface portion. A speaker unit that outputs the sound collected by the unit, and a partition that is provided in the housing, forms a space around the speaker unit, and partitions the speaker unit and the microphone unit. ,
An opening hole is formed in the housing to allow communication between the outside of the housing and the space around the speaker unit.
When the housing is mounted on the human auricle, the open hole is located outside the auricle as viewed from the center of the human head, and the penetration direction is a virtual contact with the auricle of the auricle. direction der nearly parallel or parallel to the plane is,
The housing further includes a peripheral surface portion sandwiched between the inner surface portion and the outer surface portion,
A collar part provided on the surface of the peripheral surface part so as to protrude outward from the position between the open hole and the external surface part, and is equivalent to or larger than the auricle An open-type earphone with a sound collecting microphone, characterized by comprising: An open type earphone with a sound collecting microphone according to claim 1 , and
A control device electrically connected to the open earphone with the sound collecting microphone,
Amplifying means for input for amplifying an audio signal input from the microphone unit;
The audio signal amplified by the input amplification means is adjusted so that a signal output level at a predetermined reference frequency is constant, and a low frequency band having a frequency lower than the reference frequency in the audio signal and the reference frequency Tone control means capable of adjusting the frequency characteristics of the high frequency band having a higher frequency than each other,
An auxiliary device for hearing loss, comprising: a control device having an amplification unit for output that amplifies an audio signal whose frequency characteristic is adjusted by the tone control unit and outputs the amplified signal to the speaker unit. Two open-type earphones with a sound collecting microphone according to claim 1 , and
A control device electrically connected to the two open earphones with sound collecting microphones,
Input amplifying means for independently amplifying each audio signal input from each microphone unit of the open type earphone with two sound collecting microphones;
The two audio signals amplified by the input amplifying means are independently adjusted so that the signal output level at a predetermined reference frequency is constant, and the frequency is lower than the reference frequency in each audio signal. Tone control means capable of adjusting the frequency characteristics of the frequency band and the high frequency band having a frequency higher than the reference frequency, respectively;
Balance adjusting means for adjusting the output levels of the two audio signals whose frequency characteristics are adjusted by the tone control means;
A control device having output amplifying means for amplifying the two audio signals adjusted by the balance adjusting means and outputting them to the respective speaker units of the two earphones with sound collecting microphones; Auxiliary equipment. The hearing aid according to claim 2 or 3 , wherein the reference frequency is a predetermined frequency in a range of 2000 to 4000 Hz.

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