JP2006237690A - Waterproof hearing aid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waterproof hearing aid, enabling a user to wear without worrying about the penetration of water or sweat, even if sweating or taking a bath. <P>SOLUTION: A first waterproof film 16 is stretched to a sound inlet 5 of a microphone 4, and a second waterproof film 19 is stretched to a sound outlet 12 of an earphone 11. The waterproof hearing aid is provided with a tube (a first ventilation means) 27, which makes a microphone chamber 18 formed by the first waterproof film 16 and the microphone 4 communicate with a hearing aid case chamber 22 formed by a hearing aid case 3, a tube (a second ventilation means) 28 which makes an earphone chamber 21 formed by the second waterproof film 19 and the earphone 11 communicate with the hearing aid case chamber 22, and a porous film (a third ventilation means) 24, which allows the hearing aid case chamber 22 communicate with the outside. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waterproof hearing aid in which a waterproof structure is provided at a sound inlet of a microphone or a sound outlet of an earphone.

  It is desirable for a hearing aid wearer to be able to wear a hearing aid under any circumstances. For example, when sweating by moderate exercise or bathing in an unfamiliar place such as a sports club, it is desirable to keep wearing a hearing aid because it is necessary to obtain sufficient information by hearing. However, under such circumstances, the hearing aid wearer wears the hearing aid while worrying about whether the hearing aid may break down due to the intrusion of water or sweat.

Therefore, as a waterproof structure of the ear-mounted hearing aid, a waterproof membrane holding member holding a non-porous waterproof membrane is disposed in front of the microphone mouth, and the microphone chamber formed by the waterproof membrane holding member and the microphone case is sealed. A structure with an improved state is known (for example, see Patent Document 1).
In addition, as a waterproof structure for in-ear hearing aids, a cap with a hole can be attached to the acoustic outlet connection of the hearing aid, and a microporous membrane made of non-adhesive polytetrafluoroethylene is disposed in the cap. A structure is known that facilitates sound transmission and prevents earwax, moisture, sweat, and the like from the ear canal from entering the hearing aid (see, for example, Patent Document 2).
Further, a hearing aid provided with a protective device using a non-porous diaphragm made of a material having good acoustic propagation instead of a microporous membrane, such as titanium of 0.01 mm or less, at the opening of the acoustic inlet and the opening of the acoustic outlet. Is known (see, for example, Patent Document 3).

Japanese Patent No. 2869505 European Patent No. 0310866 Japanese Patent Laid-Open No. 10-126897

  However, in the waterproof structure of the hearing aid described in Patent Document 1 and Patent Document 3, since the acoustic opening is covered with a non-porous waterproof film or a non-porous diaphragm, a sound intrusion path (microphone chamber) to the microphone and The sound discharge paths (earphone chambers) from the earphones are sealed. In such a sealed state, if there is a change in the pressure or temperature outside the hearing aid, there will be a pressure difference inside and outside these sealed spaces, and the pressure due to this pressure difference will act on the waterproof membrane, etc., and a large tension will be applied to the waterproof membrane. Occurs. As a result, there is a problem that the acoustic impedance of the waterproof membrane increases rapidly, the sound pressure attenuation by the waterproof membrane increases, and the sensitivity as a hearing aid decreases greatly.

  Further, as described in Patent Document 2, when a microporous membrane is used, there is a disadvantage that an atmospheric pressure difference does not occur, but earwax or the like tends to clog the membrane pores. In addition, the microporous material made of polytetrafluoroethylene has a higher specific gravity than a non-porous polyurethane elastomer material and the waterproof performance is reduced when the membrane is thinned. Therefore, it is difficult to sufficiently reduce the surface density of the membrane. There is a problem that it is difficult to sufficiently reduce the acoustic impedance.

  The acoustic impedance of the membrane is substantially determined by its acoustic stiffness in a frequency range lower than the first resonance frequency of the membrane. The acoustic stiffness of a circular membrane is proportional to the membrane tension and inversely proportional to the fourth power of the membrane diameter. In particular, in the case of an in-ear hearing aid, the size of the waterproof membrane is about 2 mm in diameter by design. As the membrane diameter decreases, the amount of change in membrane acoustic impedance with respect to the change in membrane tension increases rapidly. As described above, in the waterproof hearing aid, it is important to adjust the pressure inside and outside the membrane so that the membrane tension does not change.

  The present invention has been made in view of such problems of the prior art, and its purpose is to worry about the ingress of water and sweat even if you sweat or take a bath. It is intended to provide a waterproof hearing aid that can be worn without having to do so.

  In order to solve the above problem, the invention according to claim 1 is a waterproof hearing aid in which a first waterproof film is stretched at a sound inlet of a microphone and a second waterproof film is stretched at a sound outlet of an earphone. A microphone chamber formed by a waterproof membrane and a microphone communicates with a hearing aid case chamber formed by a hearing aid case, and an earphone chamber formed by a second waterproof membrane and an earphone communicates with the hearing aid case chamber. The second ventilation means and the third hearing means that the hearing aid case chamber communicates with the outside.

  According to a second aspect of the present invention, in the waterproof hearing aid according to the first aspect, the first ventilation means is provided on a side wall of a tube that protrudes into the hearing aid case chamber or a tube that forms a part of the microphone chamber. A vent or a breathable porous tube forming a part of the microphone chamber or a vent provided in the microphone case was used.

  The invention according to claim 3 is the waterproof hearing aid according to claim 1 or 2, wherein the second ventilation means is provided on a side wall of a tube that protrudes into the hearing aid case chamber or a tube that forms a part of the earphone chamber. An air permeable porous tube that forms a part of the vent hole or the earphone chamber.

  According to a fourth aspect of the present invention, there is provided the waterproof hearing aid according to the first, second or third aspect, wherein the third ventilation means is a porous membrane through which gas such as air passes but liquid such as water does not easily pass. Was used.

  The invention according to claim 5 is the waterproof hearing aid according to claim 1, 2, 3 or 4, wherein the first waterproof film and the second waterproof film are exchangeable.

As described above, according to the first aspect of the present invention, the first ventilation means for communicating the microphone room and the hearing aid case room, the second ventilation means for communicating the earphone room and the hearing aid case room, the hearing aid case room and the outside Since the microphone chamber and the earphone chamber are ventilated to the outside by providing the third ventilation means that communicates with the outside, there is no pressure difference with the outside even if there is a change in the external atmospheric pressure or temperature, and the waterproof membrane is large. Since no tension is generated, it is possible to prevent a problem that the acoustic impedance of the waterproof membrane is rapidly increased, the sound pressure is attenuated by the waterproof membrane, and the sensitivity as a hearing aid is greatly reduced.

  According to the second aspect of the present invention, since the microphone chamber and the hearing aid case chamber can be easily ventilated, the balance of atmospheric pressure between the microphone chamber and the hearing aid case chamber is smoothly performed.

  According to the invention of claim 3, since the earphone chamber and the hearing aid case chamber can be easily ventilated, the balance of atmospheric pressure between the earphone chamber and the hearing aid case chamber is smoothly performed.

  According to the fourth aspect of the present invention, since the outside and the hearing aid case chamber can be easily ventilated without allowing a liquid such as water to enter the hearing aid case chamber, the balance of the atmospheric pressure between the outside and the hearing aid case chamber can be achieved. Smoothly done.

  According to the invention which concerns on Claim 5, cleaning and replacement | exchange of a 1st waterproofing membrane and a said 2nd waterproofing membrane can be performed easily.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIGS. 1 and 2 are perspective views of the waterproof hearing aid according to the present invention, FIG. 3 is a perspective view in a state where the battery cover is opened, FIG. 4 is a sectional view in the same wearing state, and FIG. 6 is a detailed sectional view of the waterproof structure of the microphone and the first ventilation means, FIG. 7 is a detailed sectional view of the waterproof structure of the earphone and the second ventilation means, and FIG. 8 is a detailed sectional view of the third ventilation means.

As shown in FIGS. 1 to 3, the waterproof hearing aid according to the present invention is an in-ear hearing aid in which a hearing aid case 3 is constituted by a shell 1 and a face plate 2 that closes an opening of the shell 1. As shown in FIG. 4, the outer shape of the shell 1 is made to fit the wall portion of the ear canal 10 when the hearing aid is worn.
As shown in FIG. 5, the face plate 2 includes a sound inlet 5 of the microphone 4, a mounting hole 6 of the microphone 4 communicating with the sound inlet 5, a battery lid housing portion 9 in which a battery lid 8 holding the battery 7 is accommodated. Is formed. Further, a sound outlet 12 of the earphone 11 and a mounting hole 13 of the earphone 11 communicating with the sound outlet 12 are formed at the tip of the shell 1.

  In the case of an order-made hearing aid that uses the ear shape of the wearer to produce the shell 1, a vent hole 14 is provided in the shell 1 for ventilation between the outside and the external auditory canal 10 during wearing as shown in FIG. 4. It has been. However, in the case of a general-purpose type in-ear hearing aid that does not take the ear shape of the wearer, air permeability may be maintained between the outside and the ear canal through the gap between the shell formed during wearing and the ear canal wall. Expected, no vent hole is provided.

  As shown in FIG. 5, a waterproof chip 17 with a waterproof film 16 is fitted to the sound inlet 5 of the microphone 4, and the microphone 4 is fitted into the waterproof chip 17 and the mounting hole 6 and fixed with an adhesive. Thus, the microphone chamber 18 is formed. Further, a waterproof chip 20 with a waterproof film 19 stretched on the sound outlet 12 of the earphone 11 is fitted, and the earphone chamber 21 is formed by the waterproof chip 20 and the earphone 11 fitted in the attachment hole 13 and fixed with an adhesive. It is formed. Reference numeral 15 denotes a signal processing unit.

  The battery lid 8 has a through hole 23 that communicates the outside with the inside of the hearing aid case 3 (the hearing aid case chamber 22), and a cap 25 in which a porous membrane (third ventilation means) 24 is stretched in the through hole 23. Are mated. Further, since the O-ring 26 is attached to the battery lid 8, a waterproof structure is formed in which water or the like does not enter the hearing aid case chamber 22 when the battery lid 8 is closed.

  By using an elastic polymer film such as a polyurethane elastomer having a thickness of about 0.01 mm for the waterproof film 16, the acoustic impedance of the waterproof film 16 can be made as small as negligible with respect to the input acoustic impedance of the microphone 4. As a result, the sound pressure input to the microphone 4 hardly attenuates even after passing through the waterproof film 16, so that it is possible to obtain almost the same wearing feeling as when the waterproof film 16 is not attached.

  As shown in FIG. 6, the waterproof film 16 is bonded to an annular frame 16a, and then inserted into a mold when the cylindrical body 17a of the waterproof chip 17 is molded, and is fixed to the cylindrical body 17a by molding. The And the waterproof chip | tip 17 which consists of the waterproof film | membrane 16, the frame 16a, and the cylinder 17a is formed. Since the cylindrical body 17a formed using the elastic polymer material is press-fitted into the sound inlet 5 having an inner diameter slightly smaller than the outer diameter of the cylindrical body 17a, the cylindrical body 17a functions as a packing and contributes to improvement of the waterproof property of the microphone chamber 18. To do.

    Further, the waterproof membrane 19 is made of an elastic polymer film such as polyurethane elastomer having the same thickness as the waterproof membrane 16 so that the acoustic impedance of the waterproof membrane 19 is negligible with respect to the output acoustic impedance of the earphone 11. It can be made as small as possible. As a result, the sound pressure output from the earphone 11 to the ear canal hardly attenuates even if it passes through the waterproof film 19, so that it is possible to obtain almost the same wearing feeling as when the waterproof film 19 is not attached.

  As shown in FIG. 7, the waterproof membrane 19 is bonded to an annular frame 19a, and then inserted into a mold when the cylinder 20a of the waterproof chip 20 is molded, and is fixed to the cylinder 20a by molding. The And the waterproof chip | tip 20 which consists of the waterproof membrane 19, the frame 19a, and the cylinder 20a is formed. Since the cylindrical body 20a formed using the elastic polymer material is press-fitted into the sound outlet 12 having an inner diameter slightly smaller than the outer diameter of the cylindrical body 20a, the cylindrical body 20a functions as a packing and contributes to an improvement in waterproofness of the earphone chamber 21. To do.

  Since the waterproof chip 17 and the waterproof chip 20 are merely fitted to the face plate 2 or the shell 1 using elasticity, they can be easily removed using tweezers or the like, and can be replaced with new ones. . That is, the waterproof film 16 is replaceable because the waterproof chip 17 is replaceable, and the waterproof film 19 is replaceable because the waterproof chip 20 is replaceable.

  Further, as shown in FIG. 6, a tube (first ventilation means) 27 that communicates between the microphone chamber 18 and the hearing aid case chamber 22 is provided on the side surface of the microphone 4, and the pressure of the microphone chamber 18 and the hearing aid case chamber 22 is reduced. Equilibrium is taken. If the pressure balance between the microphone chamber 18 and the hearing aid case chamber 22 is not balanced, the microphone chamber 18 becomes a sealed space, and a difference in pressure occurs between the microphone chamber 18 and the outside due to changes in temperature and pressure. Then, tension is generated in the waterproof film 16 due to the difference in the atmospheric pressure, and the acoustic impedance of the waterproof film 16 is remarkably increased. As a result, the sensitivity of the hearing aid is lowered.

  As shown in FIG. 7, a tube (second ventilation means) 28 that communicates the earphone chamber 21 and the hearing aid case chamber 22 is also provided on the side surface of the earphone 11, so that the atmospheric pressure balance between the earphone chamber 21 and the hearing aid case chamber 22 is maintained. Has been taken. If the atmospheric pressure of the earphone chamber 21 and the hearing aid case chamber 22 is not balanced, the earphone chamber 21 becomes a sealed space, and a difference in atmospheric pressure occurs between the earphone chamber 21 and the outside due to changes in temperature and atmospheric pressure. Then, tension is generated in the waterproof film 19 due to the difference in atmospheric pressure, and the acoustic impedance of the waterproof film 19 is remarkably increased. As a result, the sensitivity of the hearing aid is lowered.

  As shown in FIG. 6, the microphone 4 is an electret / condenser type, and includes a box-shaped microphone case 30 in which a diaphragm 31, a back electrode electret 32, an impedance converter 33, and the like are housed. Further, the microphone case 30 is divided into a diaphragm front chamber 34 and a diaphragm rear chamber 35 by a diaphragm 31. A sound inlet 36 that communicates with the diaphragm front chamber 34 is formed at a location where the microphone case 30 faces the waterproof membrane 16. Then, the sound pressure generated in the diaphragm front chamber 34 through the waterproof film 16 and through the sound inlet 36 displaces the diaphragm 31 facing the back electrode electret 32 with an appropriate gap, and generates an acoustic signal. Convert to electrical signal.

  In the microphone 4, one or a plurality of holes (back electrode holes) 32 a are formed in the back electrode electret 32 in order to obtain good characteristics, and a small hole (membrane vent hole) 31 a is generally formed in the vibration film 31. Therefore, the diaphragm front chamber 34 and the diaphragm rear chamber 35 communicate with each other, and the atmospheric pressure of the diaphragm front chamber 34 and the diaphragm rear chamber 35 is balanced.

  Further, as shown in FIG. 7, the earphone 11 is a balanced armature type electromagnetic type, and a diaphragm 41, a coil 42, a magnet 43, an armature 44, a vibration pin 45, etc. are provided on a box-shaped earphone case 40. It is stored. The earphone case 40 is partitioned by a diaphragm 41 into a diaphragm front chamber 46 and a diaphragm rear chamber 47. A sound outlet 48 communicating with the diaphragm front chamber 46 is formed at a location where the earphone case 40 faces the waterproof film 19. In the earphone 11, a rubber tube 50 is put on a sound port 49 formed in the earphone case 40, and the tip of the rubber tube 50 is fitted in the attachment hole 13 and fixed with an adhesive.

  The sound pressure generated in the diaphragm front chamber 46 due to the vibration of the diaphragm 41 is transmitted to the outside (the ear canal) through the sound outlet 48, the earphone chamber 21, and the waterproof film 19. The diaphragm 41 is surrounded by a flexible polymer film 51 at the edge, and is attached to the inner wall of the earphone case 40 via the polymer film 51. Since the polymer film 51 has a small ventilation hole 51a, the diaphragm front chamber 46 and the diaphragm rear chamber 47 communicate with each other, and the atmospheric pressure of the diaphragm front chamber 46 and the diaphragm rear chamber 47 is balanced. .

  As shown in FIG. 8, the porous membrane (third ventilation means) 24 is made of a porous polytetrafluoroethylene membrane having a thickness of 0.3 mm and dropped on the step portion 23 a of the through hole 23 opened in the battery lid 8. After being inserted, the cap is made of a water-repellent plastic cap 25 that is press-fitted. The porous membrane 24 has the property of allowing water vapor to pass but not perspiration or water. Further, the porous membrane 24 has air permeability so that the atmospheric pressure can be balanced in about several seconds when a difference in atmospheric pressure occurs between the inside and outside of the hearing aid case chamber 22.

If the time required for atmospheric pressure equilibrium becomes longer than about 10 seconds, the pressure difference between the inside and outside of the hearing aid case chamber 22 due to a sudden change in atmospheric pressure generated by an elevator or the like is not quickly resolved, and the hearing aid is desensitized and the sensitivity is lowered. The wearer feels difficult to hear.
Therefore, it is desirable that the air pressure in the hearing aid case chamber 22 be balanced with the external air pressure in the shortest possible time without sacrificing waterproofness.

  Further, it is desirable to provide a plurality of third ventilation means for ventilating the hearing aid case chamber 22 and the outside by changing the installation location. This is because, if there is only one place, it is considered that even if sufficient air permeability is normally secured, water droplets or the like block the porous film 24 and the atmospheric pressure cannot be balanced. This is because, if a plurality of third aeration means are provided, the possibility that they are all simultaneously closed with water droplets or the like is lower than in the case of one place.

  Next, as another embodiment of the first ventilation means, as shown in FIG. 9A, a ventilation hole 55 is provided in the microphone case 30 instead of the tube 27 that communicates the microphone chamber 18 and the hearing aid case chamber 22. By providing, the atmospheric pressure balance with the hearing aid case chamber 22 can be obtained through the membrane vent 31a in which the microphone chamber 18 is opened in the vibration membrane 31.

  Further, as shown in FIG. 9B, a cylindrical sound port 30 a is formed in the microphone case 30, and a rubber tube 56 is put on the sound port 30 a, and the rubber tube 56 is fitted in the mounting hole 6 of the microphone 4. And can be fixed with an adhesive. Then, a ventilation hole 57 can be formed in the side wall of the rubber tube 56 by laser processing or the like to balance the atmospheric pressure between the microphone chamber 18 and the hearing aid case chamber 22.

  Further, by using a porous tube made of polytetrafluoroethylene resin or the like instead of the rubber tube 56, the air pressure between the microphone chamber 18 and the hearing aid case chamber 22 can be obtained without opening a vent hole in the side wall of the tube. Can be balanced. Furthermore, the ventilation hole for the atmospheric pressure balance between the microphone chamber 18 and the hearing aid case chamber 22 may be provided anywhere or a plurality of ventilation holes may be provided.

  Next, as another embodiment of the second ventilation means, as shown in FIG. 10, a ventilation hole 58 is opened by laser processing or the like on the side wall of the rubber tube 50 fitted in the attachment hole 13 and fixed by an adhesive. Thus, it is possible to balance the air pressure between the earphone chamber 21 and the hearing aid case chamber 22. Further, by using a porous tube made of polytetrafluoroethylene resin or the like instead of the rubber tube 50, the air pressure between the earphone chamber 21 and the hearing aid case chamber 22 can be obtained without opening a vent hole in the side wall of the tube. Can be balanced. Furthermore, the vent hole for balancing the atmospheric pressure between the earphone chamber 21 and the hearing aid case chamber 22 may be provided anywhere or a plurality of vent holes may be provided.

  Next, as another embodiment of the third ventilation means, as shown in FIG. 11, an opening 60 that faces the hearing aid case chamber 22 is provided in the vent hole 14, and this opening 60 is made of a porous polytetrafluoroethylene film 61. It is also possible to balance the atmospheric pressure between the hearing aid case chamber 22 and the outside through the vent hole 14. Further, by forming the vent hole 14 with a porous polytetrafluoroethylene resin tube or the like, it is possible to balance the atmospheric pressure between the hearing aid case chamber 22 and the outside without opening a vent hole in the side wall of the tube. It is possible.

If the microphone room 18 and the hearing aid case room 22 are air permeable and the earphone room 21 and the hearing aid case room 22 are too air permeable and the acoustic impedance becomes too small in the audio frequency band, the microphone room 18, the earphone room 21, There may be a problem in hearing aid characteristics due to the acoustic systems in the hearing aid case chamber 22 and the external auditory canal interfering with each other.
Therefore, the air permeability is determined so that the atmospheric pressure can be balanced in a short time of several seconds or less, and the acoustic impedance is increased to such an extent that the change in characteristics can be ignored as compared with the case without the ventilation means. In the case of the tube (first ventilation means) 27 and the tube (second ventilation means) 28 shown in FIG. 5, both inner diameter was 0.1 mm and length was 10 mm.

  According to the present invention, a waterproof hearing aid is provided that can be worn at all times without worrying about the intrusion of water or sweat even when sweating or taking a bath. Can be enlarged.

A perspective view of a waterproof hearing aid according to the present invention A perspective view of a waterproof hearing aid according to the present invention The perspective view of the state which opened the battery cover of the waterproof hearing aid which concerns on this invention Sectional drawing of the wearing state of the waterproof hearing aid according to the present invention Sectional view of waterproof hearing aid according to the present invention Detailed cross-sectional view of the waterproof structure of the microphone and the first ventilation means Detailed cross-sectional view of waterproof structure of earphone and second ventilation means Detailed sectional view of the third ventilation means It is sectional drawing of another embodiment of a 1st ventilation means, (a) is a case where a vent hole is provided in a microphone case, (b) is a case where a vent hole is provided in a rubber tube Sectional drawing of another embodiment of a 2nd ventilation means Sectional drawing of another embodiment of a 3rd ventilation means

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Shell, 2 ... Faceplate, 3 ... Hearing aid case, 4 ... Microphone, 5 ... Sound inlet, 6,13 ... Mounting hole, 11 ... Earphone, 12 ... Sound outlet, 16 ... Waterproof membrane (1st waterproof membrane), 17, 20 ... Waterproof chip, 18 ... Microphone chamber, 19 ... Waterproof membrane (second waterproof membrane), 21 ... Earphone chamber, 22 ... Hearing aid case chamber, 24 ... Porous membrane (third ventilation means), 27 ... Tube ( (First ventilation means), 28 ... tube (second ventilation means), 30 ... microphone case, 40 ... earphone case, 55, 57 ... ventilation hole (first ventilation means), 58 ... ventilation hole (second ventilation means), 61: Porous polytetrafluoroethylene membrane (third ventilation means).

Claims (5)

A waterproof hearing aid in which a first waterproof membrane is stretched at the sound inlet of the microphone and a second waterproof membrane is stretched at the sound outlet of the earphone, and a microphone chamber formed by the first waterproof membrane and the microphone is provided by the hearing aid case. A first venting means communicating with the formed hearing aid case chamber; an earphone chamber formed by a second waterproof membrane and an earphone; the second venting means communicating with the hearing aid case chamber; and the hearing aid case chamber communicating with the outside. A waterproof hearing aid comprising a third ventilation means. The first ventilation means is a tube protruding into the hearing aid case chamber, a ventilation hole provided in a side wall of a tube forming a part of the microphone chamber, or a breathable porous forming a part of the microphone chamber The waterproof hearing aid according to claim 1, wherein the waterproof hearing aid is a ventilation hole provided in a tube or a microphone case. The second venting means is a tube projecting into the hearing aid case chamber, a vent hole provided in a side wall of a tube forming a part of the earphone chamber, or a breathable porous forming a part of the earphone chamber The waterproof hearing aid according to claim 1 or 2, which is a tube. The waterproof hearing aid according to claim 1, 2, or 3, wherein the third ventilation means uses a porous membrane through which gas such as air passes but liquid such as water does not easily pass. The waterproof hearing aid according to claim 1, 2, 3 or 4, wherein the first waterproof membrane and the second waterproof membrane are exchangeable.