Hearing device

Abstract

To provide a hearing device for enabling an efficient use of a bone conduction speaker.SOLUTION: A hearing device 1 mainly includes: a plurality of bone conduction speakers 3a, 3b, 3c, 3d; a main body 7, and a headband 5 or the like. The headband 5 can be mounted on a head part of a user. The hearing device 1 includes a control section, a communication section, and an amplifier or the like. The control section can control the amplifier with respect to an acoustic electric signal received in the communication section. The amplifier executes processing of the acoustic electric signals respectively suitable for the bone conduction speakers 3a, 3b, 3c, 3d, and can transmit the signals to the bone conduction speakers 3a, 3b, 3c, 3d. Namely, the amplifier can perform at least four channel outputs with respect to the same acoustic electric signal received in the communication section, and can respectively change the acoustic electric signals to be transmitted to the bone conduction speakers 3a, 3b, 3c, 3d.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hearing device having a bone conduction speaker that allows a person to recognize sound by applying vibrations to bones. [Background technology]

[0002] Devices such as headphones and earphones (hereinafter referred to as hearing devices) have been widely used as a means of listening to music and conversations. There are two types of hearing devices: those that use air conduction and those that use bone conduction. Those that use air conduction convert the sound source input as an electrical signal into air vibrations, which are transmitted to the eardrum and vibrate it, and the vibrations of the eardrum pass through the middle ear deep inside the ear, transmitting sound information to the brain and being recognized.

[0003] On the other hand, hearing devices that use bone conduction convert acoustic signals input as electrical signals into mechanical vibrations, transmit the vibrations to the bones from an appropriate position, and allow the user to recognize the sound through bone-conducted sound transmitted by the vibrations. This hearing device that uses bone conduction does not need to be inserted into the ear canal like headphones or earphones, and is safe to wear because ambient sounds enter the ear without being blocked. In addition, because it does not use vibrations of the eardrum, even people with hearing loss can recognize sounds, and its use in hearing aids and the like is also being promoted (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 02-62199 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional air conduction speakers are often used in pairs so that they can be worn on both ears. In this way, by using a pair of air conduction speakers, it is possible to listen to so-called stereo sound sources. In other words, by listening to the L channel acoustic electric signal and the R channel acoustic electric signal from both ears, it is possible to listen to music with a wider range of sounds.

[0006] On the other hand, bone conduction speakers, which have been used to replace conventional air conduction speakers, are usually used in pairs. Here, the inventors have found that even with bone conduction speakers that are not used through both auricles, it is possible to perceive the direction from which sound is heard depending on the position where the vibration is transmitted. In other words, they have found that if a pair of bone conduction speakers is placed, for example, on both sides of the head, it is possible to perceive a stereo sound source in the same way as with air conduction speakers. For this reason, a method for using bone conduction speakers more effectively is desired.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a hearing device that can more efficiently utilize a bone conduction speaker. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention is a hearing device having three or more bone conduction speakers that convert an acoustic electric signal into vibration and output the vibration, and is characterized in that the acoustic electric signal transmitted to any one of the bone conduction speakers can be changed relative to the acoustic electric signal transmitted to the other bone conduction speakers.

[0009] It may be possible to vary the output level of the acoustic electric signal transmitted to at least some of the bone conduction speakers.

[0010] It may be possible to change the frequency band of the acoustic electric signal transmitted to at least some of the bone conduction speakers.

[0011] It may be possible to vary the temporal phase of the acoustic electric signals transmitted to at least some of the bone conduction speakers.

[0012] The device may have a plurality of amplifiers, and a sound source of an acoustic electric signal transmitted to any one of the bone conduction speakers may be different from a sound source of an acoustic electric signal transmitted to another of the bone conduction speakers.

[0013] A plurality of the bone conduction speakers may be capable of being arranged and held at different positions at least in the circumferential direction of the head.

[0014] The output level of the bone conduction speaker may be changed for each of a plurality of sound sources, allowing the user to hear acoustic electric signals from the different sound sources at different positions on the head.

[0015] The device may further include a plurality of microphones, which can be positioned in different directions around the user, and each acoustic electrical signal obtained by the microphone in each direction can be transmitted to the bone conduction speaker in a direction corresponding to the direction of each microphone.

[0016] According to the present invention, by using three or more bone conduction speakers and changing the acoustic electric signal transmitted to at least some of the bone conduction speakers relative to the acoustic electric signal transmitted to the other bone conduction speakers, it is possible to listen to sound from the bone conduction speakers more effectively compared to the conventional method of simply receiving vibrations at two points and listening to sound.

[0017] For example, if it is possible to change the output level of the acoustic electric signal transmitted to at least some of the bone conduction speakers, it is possible to adjust the volume heard depending on the part of the body. Therefore, for example, by increasing the volume in a certain direction, it is possible to sense the directionality of the sound, as if the sound is coming from that direction.

[0018] Furthermore, if it is possible to change the frequency band of the acoustic electric signal transmitted to at least some of the bone conduction speakers, it is possible to change the direction from which low and high frequencies are heard, making it possible to hear sounds with a more realistic feel.

[0019] Furthermore, if it is possible to change the temporal phase of the acoustic electric signal transmitted to at least some of the bone conduction speakers, it is possible to hear the sound of the same sound source with a slight shift. This makes it possible to reproduce reverberation, etc.

[0020] In addition, by using multiple amplifiers and making the sound source of the acoustic electric signal transmitted to one bone conduction speaker different from the sound source of the acoustic electric signal transmitted to the other bone conduction speaker, it is possible, for example, to listen to music on one side while making a phone call on the other side.

[0021] Furthermore, if multiple bone conduction speakers can be arranged and held at different positions at least in the circumferential direction of the head, the directionality of sound can be more reliably felt.

[0022] In addition, if the user can listen to acoustic electric signals from different sound sources at different positions on the head by changing the output level of the bone conduction speaker for each of the multiple sound sources, the user can sense the direction of the sound being heard for each sound source. For example, when listening to voices from multiple people, by changing the output level of the bone conduction speaker for each person, the user can listen to the voices as if each person was speaking from a different direction.

[0023] In addition, by placing multiple microphones facing different directions, it is possible to calculate the direction of the sound received by the microphones, and by adjusting the output level of the bone conduction speaker accordingly, it is possible to hear the sound as coming from the direction corresponding to the direction from which the sound was received. Effect of the Invention

[0024] According to the present invention, a hearing device capable of more efficiently utilizing a bone conduction speaker can be provided. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of a listening device 1. [Diagram 2] FIG. 1 is a diagram showing the configuration of the listening device 1. [Diagram 3] 1A and 1B are conceptual diagrams showing a state in which a user uses the hearing device 1. [Figure 4] FIG. 1 is a schematic diagram of a hearing device 1a. [Diagram 5] FIG. 2 is a diagram showing the configuration of a hearing device 1a. [Figure 6] FIG. 2 is a diagram showing the configuration of a hearing device 1b. [Figure 7] 13(a) and (b) are conceptual diagrams showing how to use the hearing device 1b. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing a hearing device 1. The hearing device 1 is mainly composed of a plurality of bone conduction speakers 3a, 3b, 3c, 3d, a main body 7, a headband 5, etc. The bone conduction speakers 3a, 3b, 3c, 3d can be conventional bone conduction type speakers that convert an acoustic electric signal into vibration, output the vibration, and transmit the vibration directly to a target part by contacting the target part.

[0027] For example, the bone conduction speakers 3a, 3b, 3c, and 3d house a vibration unit that converts an acoustic signal input as an electric signal into mechanical vibration and outputs the vibration. Note that converting an acoustic electric signal into vibration means converting an acoustic electric signal input from the outside into mechanical vibration, for example, by vibrating a diaphragm or the like with the acoustic electric signal, the acoustic electric signal is converted into mechanical vibration that is transmitted to bones. Note that in the present invention, the vibration method in the vibration unit is not particularly limited, and it is sufficient to convert an acoustic electric signal into mechanical vibration, and conventional methods such as piezoelectric, electromagnetic, and super magnetostrictive methods can be adopted.

[0028] In this embodiment, the bone conduction speakers 3a, 3b, 3c, and 3d are arranged on the headband 5 at a predetermined interval. The headband 5 can be worn on the head of the user. Therefore, in the illustrated example, the bone conduction speaker 3a is arranged near the top of the user's head, and the three bone conduction speakers 3b, 3c, and 3d are arranged at predetermined intervals around the head (from the forehead to the back of the head). At this time, the vibration transmission surfaces of the bone conduction speakers 3a, 3b, 3c, and 3d are pressed against and contact the target part of the user.

[0029] The form of the headband 5 is not limited to the illustrated example, and multiple bone conduction speakers may be arranged inside a hat or helmet, or may be combined with VR goggles. The arrangement and number of the bone conduction speakers 3a, 3b, 3c, and 3d are not limited to the illustrated example, and at least three bone conduction speakers may be arranged. In this case, it is desirable that multiple (e.g., three or more) bone conduction speakers are arranged and held at different positions in the circumferential direction of the head.

[0030] A main body 7 is disposed in a part of the headband 5. In the hearing device 1, a battery, a circuit board, etc. are housed inside the main body 7. The headband 5 houses wiring, etc. for transmitting electric signals and power from the main body 7 to each of the bone conduction speakers 3a, 3b, 3c, and 3d. The battery, the circuit board, etc. may be disposed inside each of the bone conduction speakers 3a, 3b, 3c, and 3d, instead of in the main body 7. Also, an operation unit may be provided in the main body 7 or the headband 5.

[0031] Next, the configuration of the hearing device 1 will be described. Fig. 2 is a block diagram showing the configuration of the hearing device 1. Note that the battery and the operation unit are omitted. The hearing device 1 has a control unit 11, a communication unit 13, an amplifier 15, etc. Note that, as described above, the control unit 11, the communication unit 13, the amplifier 15, etc. may be housed in the main body unit 7, may be housed in the bone conduction speaker or the headband 5, or may be distributed and arranged in each.

[0032] The communication unit 13 may receive an acoustic electric signal from the outside via a wired connection, or may receive the acoustic electric signal wirelessly from another terminal, etc., via a short-range wireless communication system such as Bluetooth (registered trademark). In the case of a wired connection, the control unit 11, communication unit 13, amplifier 15, etc. (including a battery, an operation unit, etc.) may be separate entities and connected by a cable.

[0033] The control unit 11 can control the amplifier 15 for the acoustic electric signal received by the communication unit 13. The amplifier 15 processes the acoustic electric signal suitable for each of the bone conduction speakers 3a, 3b, 3c, and 3d, and can transmit the processed signal to the bone conduction speakers 3a, 3b, 3c, and 3d. That is, the amplifier 15 can output at least four channels for the same acoustic electric signal received by the communication unit 13, and can change the acoustic electric signal to be transmitted to the bone conduction speakers 3a, 3b, 3c, and 3d. Note that it is only necessary to change the acoustic electric signal transmitted to at least some of the bone conduction speakers with respect to the acoustic electric signal transmitted to the other bone conduction speakers, rather than changing the acoustic electric signal to be transmitted to all of the bone conduction speakers 3a, 3b, 3c, and 3d.

[0034] Here, changing the acoustic electric signal transmitted to the bone conduction speakers 3a, 3b, 3c, and 3d means, as described above, that for an acoustic electric signal from the same sound source, for example, the output level (voltage), frequency band, and temporal phase can be changed. It also includes the case where acoustic electric signals from a plurality of sound sources can be transmitted separately to the bone conduction speakers 3a, 3b, 3c, and 3d. In other words, this does not include the case where the acoustic electric signals transmitted to the bone conduction speakers 3a, 3b, 3c, and 3d are all the same.

[0035] Next, an example of use of the hearing device 1 will be described. Fig. 3(a) is a conceptual plan view showing the state in which the hearing device 1 is worn, and Fig. 3(b) is a conceptual front view showing the state in which the hearing device 1 is worn. Note that Figs. 3(a) and 3(b) omit illustration of the headband 5 and main body 7, and show only the arrangement of the bone conduction speakers 3a, 3b, 3c, and 3d.

[0036] In the hearing device 1 according to the present embodiment, the headband 5 is attached to the head, so that the bone conduction speakers 3a, 3b, 3c, and 3d are pressed against various parts of the head. In order to efficiently transmit vibrations from the bone conduction speakers 3a, 3b, 3c, and 3d to the bones (including cartilage), it is desirable to use a vibrator with a size of, for example, 10φ or less. In this way, the bone conduction speakers 3a, 3b, 3c, and 3d can be arranged in a small space.

[0037] In addition, the vibration transmission surfaces of the bone conduction speakers 3a, 3b, 3c, and 3d are in direct contact with the skin of the wearer, and are therefore made of a material that does not cause pain or discomfort when worn. Examples of such materials include, but are not limited to, synthetic resin and synthetic rubber, and are preferably made of a material that is flexible and malleable.

[0038] Next, a control method by the control unit 11 will be described. In this embodiment, for example, the output level of an acoustic electric signal from the same sound source can be adjusted arbitrarily. That is, the output levels (volumes) of the bone conduction speakers 3a, 3b, 3c, and 3d can be adjusted arbitrarily. Table 1 shows an example of the output level ratios of the bone conduction speakers 3a, 3b, 3c, and 3d.

[0039] [Table 1]

[0040] As described above, the inventors discovered that the user can sense the location to which vibrations are transmitted by the bone conduction speaker as the direction of the sound that is being obtained. Furthermore, as a result of further intensive research, they discovered that by adjusting the output levels of multiple bone conduction speakers, the user can sense the sound as coming from a direction other than the direction in which the bone conduction speakers are arranged (the combined direction of the arrangement of the multiple bone conduction speakers).

[0041] Therefore, as shown in Table 1, by changing the output level ratio of the acoustic electric signals transmitted to at least some of the bone conduction speakers 3a, 3b, 3c, and 3d, it is possible to impart directionality to the same sound. For example, by setting the output level ratio of the bone conduction speakers 3a, 3b, 3c, and 3d to 0:50:50:0 (setting A), the user can sense the sound coming from direction A in FIG. 3(a). In other words, the user can sense the sound coming from between the bone conduction speakers 3b and 3c.

[0042] Similarly, by changing the output level ratio of the bone conduction speakers 3a, 3b, 3c, and 3d as B to H in Table 1, the user can sense that the sound is coming from directions B to H, respectively, as shown in FIG. 3(a). Furthermore, by setting as I to K in Table 1, the user can sense that the sound is coming from directions I to K, respectively, as shown in FIG. 3(b). In this way, by adjusting the output level ratio of the four bone conduction speakers 3a, 3b, 3c, and 3d, the user can sense that the sound is coming from any three-dimensional direction.

[0043] Also, instead of or in addition to changing the output levels of the acoustic electric signals transmitted to the bone conduction speakers 3a, 3b, 3c, and 3d, the frequency bands of the acoustic electric signals transmitted to at least some of the bone conduction speakers 3a, 3b, 3c, and 3d may be changed. Changing the frequency bands means changing the balance of the output levels of the respective frequency bands.

[0044] In this way, by adjusting the frequency band of the bone conduction speakers 3a, 3b, 3c, and 3d, it is possible to adjust the direction from which low-pitched sounds are heard and the direction from which high-pitched sounds are heard, for example. This makes it possible to arbitrarily change the sound from each direction, such as 5.1 surround or 7.1 surround, and to feel a more realistic sound in a simulated way.

[0045] In addition, the time phase of the acoustic electric signal transmitted to at least some of the bone conduction speakers 3a, 3b, 3c, and 3d may be changed. By slightly shifting the vibrations from the bone conduction speakers 3a, 3b, 3c, and 3d in time, it is also possible to produce reverberation.

[0046] In this case, when a similar method is used to produce reverberant sounds using normal earphones, etc., a slightly delayed sound is superimposed on the original sound, and the synthesized sound is heard through the same medium. On the other hand, in this embodiment, the original sound and the reverberant sound can be heard from different directions, making it possible to produce a more realistic sound. For example, in Table 1, in setting A, the bone conduction speakers 3b and 3c can be used as the main sound (sound from the front), and the bone conduction speakers 3a and 3d can be used as reverberant sounds (sound from behind or above).

[0047] As described above, according to this embodiment, by providing a plurality of bone conduction speakers 3a, 3b, 3c, and 3d and appropriately controlling the acoustic electric signal for each, it is possible to listen to sounds more effectively.

[0048] Next, a second embodiment will be described. Figure 4 is a diagram showing a hearing device 1a, and Figure 5 is a configuration diagram of the hearing device 1a. In the following description, components that perform the same functions as those in the first embodiment are given the same reference numerals as those in Figures 1 to 3, and duplicated descriptions will be omitted.

[0049] In this embodiment, microphones 17a, 17b, 17c, and 17d are provided instead of (or connected to) the communication unit. That is, the hearing device 1a can be used as a hearing aid. In the example shown in FIG. 4, the microphones 17a, 17b, 17c, and 17d are arranged at the same positions as the bone conduction speakers 3a, 3b, 3c, and 3d, but they may be arranged at different positions. When the multiple microphones 17a, 17b, 17c, and 17d are arranged facing different directions, it is preferable that each of them is a directional microphone.

[0050] In this way, when the surrounding environmental sounds and voices are received by the multiple microphones 17a, 17b, 17c, and 17d, the control unit 11 can grasp the input level of each of the microphones 17a, 17b, 17c, and 17d for each of those sounds, and can grasp from which direction the sound is coming. For example, as described above, if the input levels of the microphones 17b and 17c are approximately the same, it can be determined that the sound is coming from between them. In other words, it is possible to link audio information and directional information for each sound.

[0051] According to the sound and direction information thus obtained, the control unit 11 controls the amplifier 15 to adjust the output levels of the bone conduction speakers 3a, 3b, 3c, and 3d so that the sound comes from the obtained direction, allowing the user to feel as if the sound is coming from that direction. Note that the same effect can be obtained even if the number of microphones is less than that of the bone conduction speakers.

[0052] According to the second embodiment, the same effect as that of the first embodiment can be obtained. In this way, the hearing device can also be used as a hearing aid. That is, by using multiple microphones and arranging the multiple microphones facing different directions around the user, it is possible to transmit the respective acoustic electric signals obtained by the microphones in each direction to the bone conduction speaker in the direction corresponding to the direction of each microphone. Therefore, the user can feel the direction from which the sound is coming, rather than simply making the sound louder as with conventional hearing aids.

[0053] Next, a third embodiment will be described. Fig. 6 is a configuration diagram of a hearing device 1b according to the third embodiment. In this embodiment, a plurality of amplifiers 15a, 15b, 15c, and 15d are provided. That is, an amplifier 15a, 15b, 15c, and 15d is provided for each of the bone conduction speakers 3a, 3b, 3c, and 3d.

[0054] In the illustrated example, there is one communication unit 13, but there may be multiple communication units 13. When there is one communication unit 13, the acoustic electric signal received by the communication unit includes multiple pieces of audio information and identification information for each piece of audio information linked to each piece of audio information, and the communication unit 13 can receive multiple pieces of audio information from different sound sources.

[0055] When multiple communication units 13 are provided and a different communication unit is provided for each amplifier, identification information for each communication unit is added to the audio information received by each communication unit. That is, the hearing device 1b can identify the original sound source of each received acoustic electric signal. Therefore, the sound source of the acoustic electric signal transmitted to one bone conduction speaker can be made different from the sound source of the acoustic electric signal transmitted to the other bone conduction speaker.

[0056] The control unit 11 distributes acoustic electric signals to the corresponding amplifiers 15a, 15b, 15c, and 15d for each sound source (audio information). In this way, the bone conduction speaker to be used can be changed depending on the purpose, for example, a certain bone conduction speaker can be used for music, and other bone conduction speakers can be used for telephone conversations. In addition, in combination with the first embodiment, a microphone and a communication unit can be used together, and while listening to music or the like from the communication unit through a certain bone conduction speaker, a voice or environmental sound received from the microphone can be heard through another certain bone conduction speaker. In this case, for the voice received through the call or microphone, the output level of the frequency band corresponding to the voice can be increased more than the other frequency bands to make the voice easier to hear.

[0057] Next, an application example of the method of using the hearing device 1b will be described. The hearing device 1b can be applied to a video conference system, as shown in Fig. 7(a). In the illustrated example, a case of five people, P to T, is shown, but the present invention is not limited to this.

[0058] The voices emitted by each person P to T are picked up by a microphone, and the voice information is transmitted to the user's speaker through a line, making it possible to hear the voices. At this time, as described above, identification information is added to the voice information of each person, so that each voice information can be distinguished. Therefore, the control unit 11 can adjust the output level of the bone conduction speaker for each voice information of each person P to T. That is, different controls are performed on the amplifiers 15a, 15b, 15c, and 15d (bone conduction speakers 3a, 3b, 3c, and 3d) for each original sound source (voice picked up by the microphone of each person P to T). Note that if the number of amplifier channels is sufficient, the bone conduction speakers 3a, 3b, 3c, and 3d may be controlled by a single amplifier.

[0059] Table 2 is a diagram showing an example of adjustment of the output levels of the bone conduction speakers 3a, 3b, 3c, and 3d in response to the voice information of each person P to T.

[0060] [Table 2]

[0061] As described above, the directionality can be sensed by adjusting the output levels of the bone conduction speakers 3a, 3b, 3c, and 3d. For example, in the example shown in Table 2, the voice of person P is heard only through the bone conduction speaker 3b (left side of the user (see FIG. 3(a))). Therefore, the voice of person P can be sensed as coming from the left side of the user. Also, the voice of person Q is heard through the bone conduction speaker 3b (left side of the user (see FIG. 3(a))) and the bone conduction speaker 3c (right side of the user (see FIG. 3(a))) at an output level ratio of about 7:3. Therefore, the voice of person Q can be sensed as coming from diagonally in front of the left of the user.

[0062] In this way, by controlling the system so that each person's voice comes from a different direction, it feels like a virtual conference with people positioned as shown in Figure 7(b). In this way, for example, when two people speak at the same time, in a conventional system, their voices overlap and are heard through the same speaker, making it difficult to distinguish between them. However, when using this listening device, the voices of each person come from different directions, making it possible to distinguish between the voices to some extent, just like in a conference room.

[0063] According to the third embodiment, the same effect as the first embodiment can be obtained. In this way, the hearing device does not necessarily have to use the same sound source, and acoustic electric signals from different sound sources (including sounds picked up by different microphones) may be transmitted to each of the bone conduction speakers 3a, 3b, 3c, and 3d. In addition, by changing the output levels of the bone conduction speakers 3a, 3b, 3c, and 3d for each of the multiple sound sources, the user can hear acoustic electric signals from each of the different sound sources at different positions on the head. Therefore, the user can feel the sound coming from each sound source as coming from a different direction.

[0064] Although the embodiment of the present invention has been described above with reference to the attached drawings, the technical scope of the present invention is not limited to the above-described embodiment. It is clear that a person skilled in the art can think of various modifications or alterations within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0065] For example, as described above, when transmitting different acoustic and electric signals to the bone conduction speakers 3a, 3b, 3c, and 3d, the user may be able to appropriately select and adjust the contents and the extent of the signals using the operation unit. [Explanation of symbols]

[0066] 1, 1a, 1b... Listening device 3a, 3b, 3c, 3d………Bone conduction speaker 5. Headband 7...Main body 11...Control unit 13. Communications Department 15, 15a, 15b, 15c, 15d...Amplifier 17a, 17b, 17c, 17d………Mike

Claims

1. 1. A hearing device, comprising: The device has three or more bone conduction speakers that convert an acoustic electric signal into vibration and output the vibration, 13. A hearing device, comprising: a hearing aid, the hearing aid being adapted to change the acoustic electric signals transmitted to at least some of said bone conduction speakers relative to the acoustic electric signals transmitted to other of said bone conduction speakers.

2. 2. The hearing device according to claim 1, wherein the output levels of the acoustic electric signals transmitted to at least some of the bone conduction speakers can be changed.

3. 2. The hearing device according to claim 1, wherein the frequency bands of the acoustic electric signals transmitted to at least some of the bone conduction speakers can be changed.

4. 2. The hearing device according to claim 1, wherein the temporal phases of the acoustic electric signals transmitted to at least some of the bone conduction speakers can be changed.

5. 2. The hearing device according to claim 1, further comprising a plurality of amplifiers, the sound source of the acoustic electric signal transmitted to one of the bone conduction speakers being different from the sound source of the acoustic electric signal transmitted to the other of the bone conduction speakers.

6. 2. The hearing device according to claim 1, wherein a plurality of said bone conduction speakers can be arranged and held at different positions at least in the circumferential direction of the head.

7. 2. The hearing device according to claim 1, wherein the output level of the bone conduction speaker is changed for each of a plurality of sound sources, thereby enabling the user to hear acoustic electrical signals from each of the different sound sources at different positions on the head.

8. Further comprising a plurality of microphones; A plurality of the microphones can be arranged around the user facing different directions, 2. The hearing device according to claim 1, wherein each of the acoustic electric signals obtained by the microphones in each direction can be transmitted to the bone conduction speaker in a direction corresponding to the direction of each of the microphones.

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