JP6475500B2 - Cartilage conduction hearing aid - Google Patents

Description

  The present invention relates to a cartilage conduction hearing aid configured to transmit vibration according to an electric signal to an ear cartilage.

  In general, a hearing-impaired person such as an ear canal obstruction cannot use an air conduction hearing aid. For example, it is necessary to use a bone conduction hearing aid that transmits sound by vibrating a skull. However, since the bone-conducting hearing aid has a structure in which the vibrator is crimped to, for example, a part of a side bone, there is a drawback that a feeling of pressure or pain occurs when worn for a long time. In order to overcome such drawbacks, in recent years, it is expected that the pathway of cartilage conduction is used for hearing aids. Various techniques have been proposed in the past. For example, Patent Document 1 includes a bone conduction speaker incorporating a bone conduction driver, and is used in a state where the speaker head is in contact with the opening of the ear canal and the vicinity thereof. An ear-mounted hearing aid is disclosed. Further, for example, Patent Literature 2 discloses a bone-conducting speaker having a structure built in an outer end portion of an ear mold formed in the shape of an ear canal.

JP 2010-192975 A JP 2000-166959 A

  In general, when using a hearing aid, it is a challenge to suppress howling caused by the sound output from the earphone to the ear canal being fed back to the microphone of the hearing aid. Of course, it is required to do so. However, in the above-mentioned Hearing Aid in Patent Document 1, the opening of the ear canal and the speaker head abutting on the opening are formed in a shape having a substantially circular cross section, but the shape of the user's ear concha cavity is There are many cases where a speaker head having a substantially circular cross section does not fit. Therefore, the sound output from the bone conduction speaker is emitted from the periphery of the speaker head to the outside, and howling easily occurs. In the bone conduction speaker of Patent Document 2, although the ear mold conforms to the shape of the ear canal, the sound emitted due to the vibration of the bone conduction speaker is actually generated due to the contact state between the ear mold and the skin. By doing so, howling may occur.

  The present invention has been made to solve these problems, and it is an object of the present invention to effectively suppress the occurrence of howling in a cartilage conduction hearing aid including an ear mold inserted into the ear canal.

  In order to solve the above-described problems, the present invention includes an ear mold (12) adapted to at least the shape of the ear canal (20), and the ear mold includes a vibration section (13) that generates vibration based on an electric signal. In the state where the ear mold is inserted into the ear canal in a state where the ear mold is inserted into the outer ear canal, a liquid or semi-solid application having an acoustic impedance close to that of the human body is higher in viscosity than water on the surface region facing the ear cartilage Gel (30) as an agent is applied.

  According to the cartilage conduction hearing aid of the present invention, when the ear mold is inserted into the external auditory canal when worn on the human body, the vibration generated by the vibration section is caused by the gap between the surface of the ear mold and the human body being filled with the coating agent. It is transmitted to cartilage located in the vicinity (hereinafter referred to as “ear cartilage”). Therefore, the presence of a coating agent that is more viscous than water and has an acoustic impedance close to that of the human body makes it possible to reduce the radiated sound that accompanies the vibration of the vibration part and effectively suppress howling.

  The coating agent may contain various components as long as the coating agent has a higher viscosity than water and satisfies the characteristics having an acoustic impedance close to that of the human body. However, a coating agent satisfying the above-mentioned characteristics can be easily obtained by mixing other components with the main component water.

  The ear mold is preferably formed in a surface shape that matches the shape of the ear canal and the periphery of the opening. Thereby, the path of the radiated sound output from the external auditory canal can be reliably covered with the coating agent, and the howling prevention effect of the cartilage conduction hearing aid can be enhanced.

  The vibration unit may be configured by an electromechanical converter that converts an electric signal into mechanical vibration using a magnetic circuit. For example, a balanced armature type vibrator that displaces the armature using a magnetic circuit can be employed.

  The present invention can be applied to cartilage conduction hearing aids having various structures such as an ear hook type and an ear hole type. The ear-mounted cartilage conduction hearing aid includes, for example, a hearing aid main body that supplies an electric signal to the vibration part, and the vibration part and the hearing aid main body are electrically connected via a wiring that transmits the electric signal. The structure can be adopted. In this case, the hearing aid main body can be provided with at least a microphone for converting sound coming from the outside into an electrical signal.

  According to the present invention, when wearing a cartilage conduction hearing aid that transmits vibration from the vibration part to the ear cartilage, an ear mold having a surface coated with a coating agent that is more viscous than water and has an acoustic impedance close to that of the human body is applied to the ear canal. Therefore, it is possible to reduce the radiated sound accompanying the vibration of the vibration part and to effectively suppress the occurrence of howling in the cartilage conduction hearing aid.

It is a perspective view which shows the whole structure of the cartilage conduction hearing aid of this embodiment. It is a figure which shows the typical cross-section in the state which mounted | wore with the cartilage conduction hearing aid of FIG. It is a figure which shows the measurement result for verifying the effect of the cartilage conduction hearing aid of this embodiment. It is a figure which shows the relationship between the density | concentration of the gel apply | coated to the surface of an ear mold, and sound pressure.

  A preferred embodiment of the present invention will be described with reference to the accompanying drawings. However, the embodiment described below is an example to which the present invention is applied, and the present invention is not limited by the contents of the present embodiment. Below, the form which applied this invention to the cartilage conduction hearing aid comprised so that the vibration according to an electrical signal may be transmitted to an ear cartilage is demonstrated.

  Hereinafter, the basic structure of the cartilage conduction hearing aid according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the entire structure of the cartilage conduction hearing aid 1, and FIG. 2 is a diagram showing a schematic cross-sectional structure in a state where the cartilage conduction hearing aid 1 of FIG. 1 is mounted. As shown in FIG. 1, the cartilage conduction hearing aid 1 according to the present embodiment includes a hearing aid body 10, a tube 11, and an ear mold 12.

  In the configuration of FIG. 1, the hearing aid main body 10 includes a microphone that converts external sound into an electric signal inside a housing made of resin or the like having a shape that can be worn on the rear part of the auricle, and an electric power output from the microphone. A signal processing unit such as a DSP (Digital Signal Processor) that performs signal processing such as predetermined hearing aid processing on the signal, a battery that supplies power to each unit of the cartilage conduction hearing aid 1, and the like are incorporated. The surface of the hearing aid main body 10 is provided with an operation unit 10a for operating the cartilage conduction hearing aid 1, a battery holder (not shown) for detachably storing a battery, and the like. The tube 11 has one end connected to the hearing aid body 10 and the other end connected to the ear mold 12. The tube 11 is formed of a material such as a synthetic resin having flexibility, and a wiring for transmitting an electrical signal from the hearing aid main body 10 to the vibrating portion 13 (FIG. 2) of the ear mold 12 is housed therein.

  As shown in FIG. 2, the ear mold 12 is made of a material such as a resin that is molded so as to conform to the shape around the ear canal 20 and its opening. A vibration unit 13 that generates vibration according to an electrical signal transmitted from the hearing aid main body 10 via the tube 11 is incorporated at a substantially central position near the tube 11 of the ear mold 12. An electromagnetic or electrodynamic electromechanical transducer can be used as the vibrator constituting the vibrating section 13. For example, the vibrating section 13 can be configured by a balanced armature type vibrator that displaces the armature using a magnetic circuit.

  The cartilage conduction hearing aid 1 is characterized in that it uses a cartilage conduction path as a sound conduction path. Therefore, as shown in FIG. 2, a predetermined surface region of the ear mold 12 faces the ear cartilage 21 in a state where the ear mold 12 is inserted into the ear canal 20. As a result, the vibration generated by the vibration part 13 is transmitted from the surface region of the ear mold 12 to the ear cartilage, so that the user can recognize it as sound. In the cartilage conduction hearing aid 1 of the present embodiment, since the tip of the ear mold 12 faces the space in the ear canal 20, the air conduction path from the ear mold 12 to the eardrum in addition to the cartilage conduction path described above. Can also be used.

  In addition, the cartilage conduction hearing aid 1 of the present embodiment is characterized in that a gel 30 as a liquid or semi-solid coating agent is applied to a surface region of the ear mold 12 that faces the ear cartilage 21. That is, the gel 30 is embedded between the surface area of the ear mold 12 and the human body (skin around the ear canal 20 and its opening) with the ear mold 12 inserted into the ear canal 20. The role of the gel 30 is to reliably transmit the vibration of the ear mold 12 including the vibration part 13 to the human body. Therefore, in this embodiment, it is necessary to use the gel 30 having a higher viscosity than water and having an acoustic impedance close to that of the human body. When such a gel 30 is not used, the radiated sound accompanying the vibration of the vibration unit 13 cannot be reduced, and howling may occur in the cartilage conduction hearing aid 1. In order to prevent such howling, the present embodiment adopts a method of applying the gel 30 to a predetermined surface region of the ear mold 12 inserted into the ear canal 20.

  FIG. 3 is a diagram showing the measurement results of the frequency characteristics of the loudness generated in the gap G (FIG. 2) under the conditions assumed in the present embodiment in order to verify the above effect. Specifically, when an earplug (ear mold) capable of completely closing the external ear canal 20 is created using an ear shape of a subject collected in advance, and sound is transmitted to the ear cartilage 21 by a vibrator fixed to the earplug. Furthermore, the sound generated at a distance of about 5 mm from the earplug to the outside was measured with a microphone. Sonojelly (registered trademark) (manufactured by Toshiba Medical Supplies Co., Ltd.) having an acoustic impedance close to that of the human body was used as the gel 30 on the surface of the earplug. As shown in FIG. 3, the average value of the sound pressure levels of five subjects was compared for each of the case where the gel 30 was not applied to the earplug and the case where the gel 30 was applied over a wide frequency range. As a result, a decrease in the sound pressure level due to the application of the gel 30 was recognized particularly in a high frequency region, and the effect of suppressing howling noise could be confirmed.

  Next, FIG. 4 is a diagram showing the relationship between the weight ratio of water as the main component and the above-described sound pressure level, focusing on the viscosity among the conditions of the gel 30 of the present embodiment. That is, under the same measurement conditions as in FIG. 3, the gel 30 whose concentration was changed by adding water to the above-mentioned sono jelly was applied to the above-mentioned earplugs, and the sound pressure level was measured as described above. Specifically, the three sonojelly weight ratios of 0% (water only), 60%, and 100% were compared. In addition, since sono jelly itself also contains a water component, for example, even when the weight ratio of sono jelly is 60%, it should be noted that the actual water ratio is greater than 40%.

  As is apparent from FIG. 4, when only water corresponding to a weight ratio of 0% of sono jelly is applied, the sound pressure level is increased particularly in a high frequency range as compared with the weight ratio of 60% and 100%. . It is known that the acoustic impedance of water itself is relatively close to the human body, but it is difficult to maintain a state where the gap G (FIG. 2) between the earplug and the human body is filled because the viscosity of water is too low. Therefore, it is considered that the sound pressure level increases. Therefore, in order to obtain the howling suppression effect, it is desirable that the viscosity of the gel 30 applied to the earplug is sufficiently higher than that of water.

  As described above, by adopting the cartilage conduction hearing aid 1 according to the present embodiment, radiation sound due to vibration is reduced, and therefore, howling in the cartilage conduction hearing aid 1 can be suppressed. In particular, a hearing-impaired person such as ear canal obstruction that cannot use an air conduction hearing aid can enjoy a remarkable effect when using the cartilage conduction hearing aid 1 of the present embodiment. Further, in the cartilage conduction hearing aid 1, there is room for increasing the gain for the electrical signal of the cartilage conduction hearing aid 1 to the extent that the howling can be suppressed, and a sufficient volume for the user can be secured.

  In the cartilage conduction hearing aid 1 of the present embodiment, the gel 30 applied to the ear mold 12 is a liquid or semi-solid coating agent and may be lost after a predetermined time has elapsed. In this case, a sufficient amount of the gel 30 can always be maintained by reapplying the gel 30 to the ear mold 12 at a desired time interval.

  As described above, the contents of the present invention have been specifically described based on the present embodiment, but the cartilage conduction hearing aid 1 according to the present invention is not limited to the structure disclosed in the above-described embodiment, and can be variously within a range not departing from the gist thereof. Changes can be made. For example, FIG. 2 shows an example in which the surface shape of the ear mold 12 matches the external auditory canal 20 and the shape of the periphery of the opening. However, if the ear mold 12 can be inserted into the external ear canal 20, the portion around the opening of the surface shape is removed. A miniaturized ear mold 12 may be used. Further, for example, in the present embodiment, the case where the present invention is applied to an ear-mounted cartilage conduction hearing aid has been described. However, if the ear mold 12 to which the gel 30 is applied is provided on the surface, the ear-analyzing type is used. The present invention can also be applied to a cartilage conduction hearing aid.

DESCRIPTION OF SYMBOLS 1 ... Cartilage conduction hearing aid 10 ... Hearing aid main body 11 ... Tube 12 ... Ear mold 13 ... Vibrating part 20 ... External auditory canal 21 ... Ear cartilage 30 ... Gel

Claims (6)

It has an ear mold that fits at least the shape of the ear canal,
The ear mold is provided with a vibration part that generates vibration based on an electric signal,
In the state where the ear mold is inserted into the ear canal, a liquid or semi-solid coating agent having a higher acoustic viscosity than water and an acoustic impedance close to that of the human body is present on the surface region where the ear mold faces the ear cartilage. A cartilage conduction hearing aid characterized by being applied.   The cartilage conduction hearing aid according to claim 1, wherein the coating agent contains water as a main component. 3. The cartilage conduction hearing aid according to claim 1 , wherein the ear mold has a surface shape that matches a shape of the outer ear canal and a periphery of an opening thereof. 4.   The cartilage conduction hearing aid according to any one of claims 1 to 3, wherein the vibration section includes an electromechanical transducer that converts the electrical signal into mechanical vibration using a magnetic circuit.   2. A hearing aid main body for supplying the electrical signal to the vibration part, wherein the vibration part and the hearing aid main body are electrically connected via a wiring for transmitting the electrical signal. To 4. The cartilage conduction hearing aid according to any one of claims 1 to 4.   The cartilage conduction hearing aid according to claim 5, wherein the hearing aid main body is provided with at least a microphone for converting sound coming from the outside into the electric signal.

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