WO2014196851A1

WO2014196851A1 - An in-ear two-way communication device with reduced interference

Info

Publication number: WO2014196851A1
Application number: PCT/MY2014/000100
Authority: WO
Inventors: Jin Hem Thong
Original assignee: Jin Hem Thong
Priority date: 2013-05-20
Filing date: 2014-05-09
Publication date: 2014-12-11

Abstract

This disclosure describes a two-way communication device (100) for communicating with a communication gadget comprising a housing disposed within the external auditory canal (112) of a user that is divided into a sound capturing part (101) which is positioned at a sound capturing region (109) within the external auditory canal (112) and a sound emitting part (102); a sound capturing component associated with the sound capturing part (101) of the device for capturing vocal sound waves of the user to be transmitted to the communication gadget that is propagated in the air within the sound capturing region (109) which is caused by vibrations along the walls (113) of the external auditory canal (112) and/or directly from the walls of the external auditory canal (112) when the user is producing vocal sound; a sound emitting component associated with the sound emitting part (102) for emitting sound signals received from the communication gadget at a sound emitting region (110) within the external auditory canal (112) to be propagated to the tympanic membrane (111) of the ear; wherein the sound waves emitted from the communication gadget is prevented to be captured by the sound capturing component by a first barrier (104) of the device (100) that is positioned within the external auditory canal (112) to separate the sound capturing region (109) and the sound emitting region (110).

Description

AN IN-EAR TWO-WAY COMMUNICATION DEVICE

WITH REDUCED INTERFERENCE

FIELD OF INVENTION

The disclosure relates to a communication device that captures the vocal sound waves of a user created from the vibration of the external auditory canal walls of the user while the user is producing voice by a sound capturing component, as well as emits sound signals received from any communication gadgets of a another user over the other end of a communication connection line by a sound emitting component. Such invention is equipped with at least one barrier for segregating the sound capturing and emitting regions within the ear so that adverse and undesired interference from either regions or from either components can be minimized up to elimination.

BACKGROUND OF THE INVENTION

Vocal sound waves are user's voice propagated from the vibration of the walls of the external auditory canal while the user is producing voice. These vocal sound waves can be detected, captured and transmitted to any communication gadget used by at least another person over the other end of the communication connection line. Therefore, the external auditory canal wall, being an air-filled cavity, not only functions as a sound-receiving canal, but can also be used as a sound-propagating canal for the voice of a user while the user is producing voice. In addition to that, the vocal sound waves can also be captured directly from the walls of the external auditory canal.

To facilitate communication between at least two parties, a communication device must have as a fundamental requirement two key components: a sound capturing component for detecting and capturing vocal sound waves of a user's voice within the external auditory canal to be sent to any communication gadget over the other end of the communication connection line; and a sound emitting component for emitting sound signals received from the communication gadget. However, these two components have to be placed together in close proximity within the narrow and small spaced external auditory canal, resulting in the occurrence of adverse and undesired interference issues including but not limited to the echo and feedback phenomena, Echo or double talk happens in a close-loop conversation between two persons over a telecommunication line where one is a caller and the other a receiver. The caller's voice emitted by the sound emitting component at the receiver's end can be recaptured by the sound capturing component at the receiver's end and transmitted back to the caller due to close proximity between the sound emitting component and the sound capturing component at the receiver's end, thus causing the caller to hear his/her own voice, creating an echo effect.

On the other hand, feedback happens in a situation where high-frequency sound signals emitted by the sound emitting component is picked up by the sound capturing component at the receiver's end and amplified, the amplified captured sound signals are resent to the sound emitting component and recaptured by the sound capturing component at the caller's end, forming a looped signal. This vicious cycle gradually leads to an irritating crescendo of high-pitched sound signals. Employing methodologies such as, signal recognition and filtration methodologies could solve these issues. However this disclosure introduces simple and effective mechanical and physical means to minimise the interaction and/or interference between the sound capturing component and sound emitting component for solving the issues described above. To facilitate communication between at least two parties, a device having a sound capturing component for capturing the sound waves of a user's voice within the external auditory canal to be sent to another person and a sound emitting component for emitting sounds received from the communication device of another person could be devised. However, these two components have to be placed together in close proximity within the narrow and small spaced external auditory canal, resulting in the occurrence of issues including but not limited to the feedback and echo phenomena, whereby undesired captured sounds emitted from the sound emitting component are captured by the sound capturing component.

SUMMARY OF INVENTION

One aspect of this disclosure is to provide an in-ear two-way communication device having a sound capturing component for detecting and capturing the vocal sound waves of a user's voice created from the vibration of the external auditory canal walls of the user while the user is producing voice, as well as a sound emitting component for emitting sounds, received from any communication gadget or from at least another person over the other end of the communication connection line into the external auditory canal of the user.

Another aspect of this disclosure is to provide an in-ear two-way communication device that is capable of reducing up to eliminating adverse and undesired interference from either of the sound capturing component or sound emitting component by using physical barriers to segregate the regions where the human vocal sounds are captured and emitted in the external auditory canal of the user, and segregate the parts of the device where the sound capturing and sound emitting functions are carried out Still another aspect of this disclosure is to provide an in-ear two-way communication device that is capable of transmitting softly spoken human vocal sound such as whispers, to any communication gadget over the other end of the communication connection line, in environments that require quietness or subdued conversations. Yet another aspect of this disclosure is to provide an in-ear two-way communication device that can be placed, affixed or applied comfortably and securely to any part of the auditory system of a human being or living creature spanning from the pinna to the tympanic membrane of the human being or living creature. Also another aspect of this disclosure is to provide an in-ear two way communication device that can be built into any communication gadget worn around the neck, face and/or head of a human being or living creature such as, but not limited to, headgears such as helmets, face masks, and eye-wear such as spectacles or goggles. At least one of the preceding aspects is met, in whole or in part, by this disclosure, in which the embodiment of this disclosure describes a two-way communication device (100) for communicating with a communication gadget comprising a housing disposed within the external auditory canal (112) of a user that is divided into a sound capturing part (101) which is positioned at a sound capturing region (109) within the external auditory canal (112) and a sound emitting part (102); a sound capturing component associated with the sound capturing part (101) of the device for capturing vocal sound waves of the user to be transmitted to the communication gadget that is propagated in the air within the sound capturing region (109) which is caused by vibrations along the walls (113) of the external auditory canal (112), and/or directly from the walls of the external auditory canal (112) when the user is producing vocal sound; a sound emitting component associated with the sound emitting part (102) for emitting sound signals received from the communication gadget at a sound emitting region (110) within the external auditory canal (112) to be propagated to the tympanic membrane (111) of the ear; wherein the sound waves emitted from the communication gadget is prevented to be captured by the sound capturing component by a first barrier (104) of the device (100) that is positioned within the external auditory canal (112) to separate the sound capturing region (109) and the sound emitting region (110).

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a diagrammatic representation of one of the preferred embodiments of the invention used within the external auditory canal. Figure 2 shows a diagrammatic representation of one of the preferred embodiments of the invention where the vocal sound waves, propagated by the vibrations of the walls of the auditory canal as the user is producing voice, in the sound capturing region are flowing into the sound capturing part of the device to be captured by the sound capturing component; and emitted sound signals, transmitted from any communication gadget used by at least another person over the other end of the communication connection line are flowing out from the sound emitting part of the device into the sound emitting region, to the tympanic membrane.

Figure 3 shows diagrammatic representations of some examples where the sound capturing part of the device in the sound capturing region is segregated from the sound emitting part of the device in the sound emitting region in relation to the tympanic membrane.

Figure 4 shows a graphical representation of one of the preferred embodiments of an example in Figure 3 (a) of the disclosure where the device is used in association with an associated gadget connected via permanent or temporary affixations and/or attachments such that the associated gadget becomes a permanent or temporary integral part of the device. Figure 5 shows a graphical representation of one of the preferred embodiments of an example in Figure 3 (a) of the disclosure where the device is used in association with an associated gadget connected to the device via wireless technologies, wherein the associated gadget is divided into two parts, one of which is attached to the device whereas the other part is attached to a base gadget.

Figure 6 shows a graphical representation of one of the preferred embodiments of an example in Figure 3 (a) of the disclosure where the device is used in association with associated gadgets connected to the device via audio connection cables, wherein the associated gadget is divided into two parts, one of which is attached to the device whereas the other part is attached to a base gadget.

Figure 7 shows a diagrammatic representation of one of the preferred embodiments of the invention where the sound capturing part is fitted closely to the walls of the external auditory canal for capturing vocal sound waves propagated directly from the walls of the external auditory canal to the sound capturing part.

DETAILED DESCRIPTION OF THE INVENTION The disclosure describes an in-ear two-way communication device (100) used for verbally communicating with one or more users in a telecommunication line. The device (100) is applicable in a broad class of base gadgets for communication over long distances far away from sight between at least two persons or entities; communication between at least two persons or entities over short distances or within each person's or entity's sight; communication between at least one human and at least one non-human living creature over long and short distances and/or communication between at least one person and at least one gadget over long distances far away from sight and within sight. The person-to-gadget communication may even include person-to-robot; a robot to mean any human-crafted appliance that obeys human commands or any human-crafted appliance that uses its own artificial intelligence to make decisions.

The term 'two-way' defines the transmitting and receiving routes of sound waves or signals. 'In-ear' on the other hand, indicates the interior of the ear, mainly the external auditory canal (112).

The device (100) is capable of transferring the voice of the device's user in the form of vocal sound waves propagating within the external auditory canal (112) due to the vibration of the external auditory canal walls (113), when the user produces vocal sound to at least a communication gadget at the other end of the communication connection line. Therefore, the device (100) is modeled in a way so that it could be adapted to be applied, wore or affixed to the ear, preferably from the pinna (114) until an area before the tympanic membrane (111) as the communication device (100) transfers the sound waves that propagates within the external auditory canal (112) when the user of the device (100) produces voice to at least one communication gadget.

The term 'user' used herein refers to a person using the device (100) to communicate with a communication gadget used by another person at the other end of a communication connection line. The communication gadget could be any gadgets such as a phone, walkie-talkie handset, tablet, computer and the like with calling functions that is capable of communicating with the device (100) between two entities such as but not limited to human beings over long distances, out of sight or short distance, or within sight. The device (100) could also be an example of the communication gadget in which two users utilize the device (100) to communicate with each other over the communication connection line. The communication connection line is a broad term to indicate audio communication using digital or analog means between at least two separate entities such as but not limited to human beings. Referring to Figure 1 and Figure 2, the external auditory canal communication device

(100) contains three main parts: a sound capturing part (101), a sound emitting part (102) and a barrier (104) that all are housed within a structure. The sound capturing part (101) is disposed at a sound capturing region (109) within the external auditory canal (112) whereas the sound emitting part (102) is situated at the sound emitting region (110) inside the external auditory canal (112), whereby both regions (109, 110) are segregated by a first barrier (104). The sound capturing part (101) is the part of the device where vocal sound waves flow into it, and are detected and captured by the sound capturing component associated to the sound capturing part (101). The sound capturing part (101) is located within the sound capturing region (109) inside the external auditory canal (112). Vocal sound waves are propagated from the vibration of the walls (113) of the external auditory canal (112) in the sound capturing region (109) while the user is producing voice. The sound capturing part (101) may or may not have physical walls. In such a case when the sound capturing part (101) has no physical walls, the sound capturing part

(101) could be integrated with the device (100) by virtue of certain skeletal frames that holds the sound capturing part (101) to the device (100). In such cases when the sound capturing part (101) has physical walls, the sound capturing part (101) could have certain parts of its physical walls formed with openings to allow vocal sound waves, propagated from the walls (113) of the auditory canal (112) in the sound capturing region (109), to flow into the sound capturing part (101) to be detected and captured by the sound capturing component. Examples of openings in the physical wall of the sound capturing part (101) are, but not limited to, apertures, slits, physical walls in the form of a sponge or net, or perforated physical walls.

The sound capturing part (101) may, may not, or partially contain the sound capturing component. The term 'sound capturing component' used herein describes the physical element which performs the function of vocal sound waves detection and capturing for the purpose of transmission of the vocal sound waves of any communication gadgets to the other end of the communication connection. The sound capturing component is capable of converting the vocal sound waves of the user into electrical signals. Transducers including but not limited to microphones could be applied as a sound capturing component.

In such a case when the sound capturing component is not or partially located in the sound capturing part (101), an expedient way to direct vocal sound waves, which are flowing into the sound capturing part (101), to be detected and captured by the sound capturing component is by way of, for example but not limited to, using some sound conductive means such as an opening or a channel.

With reference to Figure 7, the sound capturing part (101) is fabricated in such a way that it fits closely and in direct contact to the walls of the external auditory canal (112) in order to capture vocal sound waves propagated directly from the walls (113) of the external auditory canal (112) to the sound capturing part (101).

On the other hand, the sound emitting part (102) is the part of the device (100) where the sound emitting component that is associated to the sound emitting part (102) receives and emits sound signals in wave form received from the communication gadget at the other end of the communication connection line into the sound emitting region (110). The emitted sound signals then propagate to the tympanic membrane (111).

The sound emitting part (102) may or may not have a physical wall. In such a case when the sound emitting part (102) has no physical wall, the sound emitting part (102) could be integrated with the device (100) by virtue of a certain physical part of the sound emitting part (102) being affixed to the device (100); or the sound emitting part (102) is free of any physical shape and form or free of any physical demarcation. In such cases when there is a physical wall, the sound emitting part (102) could have certain parts of its physical wall formed with openings to allow emitted sound signals, which are emitted by the sound emitting component, to flow out from the sound emitting part (102) in the sound emitting region (110), and be propagated to the tympanic membrane (111). Examples of openings in the physical wall of the sound emitting part (102) are, but not limited to apertures, slits, physical walls in the form of a sponge or net, or perforated walls. Besides that, the sound emitting part (102) could be in the form of a channel that is connected to the sound emitting component which is positioned partially or completely outside of the device (100) or the ear, and is extended through the first barrier (104) towards the sound emitting region (110) for allowing sound signals emitted from the sound emitting component to propagate into the sound emitting region (110).

The sound emitting part (102) may, may not, or partially contain the sound emitting component. The sound emitting component functions to receive sound signals from the communication gadget to be emitted within the external auditory canal (112) for the user to listen, thus facilitating two-way communication between the user and the person using the second communication device. The sound emitting component could be a transducer such as a speaker that converts electrical signals received from the second communication device into sound signals. In such a case when the sound emitting component is not or partially located in the sound emitting part (102), an expedient way to direct emitted sound signals from the sound emitting component to the sound emitting part (102) in the sound emitting region (110), is by way of, for example but not limited to, using some sound conductive means such as an opening or a channel. As the sound capturing region (109) where the sound capturing part (101) is positioned at has to be located within the external auditory canal (112), and the sound emitting region (110) is also inside the external auditory canal (112), the sound signals emitted at the sound emitting region (110) could be easily propagated in to the sound capturing part (101) in the sound capturing region (109) and captured by the sound capturing component. Therefore, a first barrier (104) of the device (100) is essential to be positioned within the external auditory canal for separating the sound capturing region (109) and the sound emitting region (110) so that both sound capturing part (101) and the sound emitting part (102) could operate independently of each other without having the sound signals emitted at the sound emitting region (110) to intrude the sound capturing region (109) and vice versa, and hence reducing up to eliminating adverse and undesired interference.

Figure 3 shows different configurations of the first barrier (104) segregating both regions. The first barrier (104) could be positioned vertically as shown in Figure 3(a), where the sound emitting region (110) is close to the tympanic membrane (111) for the tympanic membrane (111) to receive the sound signals easily. On the other hand, Figure 3(b) shows the first barrier (104) being disposed at an inclined angle with the sound emitting region (110) closer to the tympanic membrane (111) than the sound capturing region (109). A horizontal first barrier is also applicable as depicted in Figure 3(c) where the sound capturing part (101) could only allow the sound waves created through vibration from one side of the auditory canal wall (113) to enter it and direct the sound waves to the sound capturing component. The dash lines as depicted in Figure 3 indicate perforations of the physical walls of the sound capturing part ( 101 ) and sound emitting part ( 102).

In this disclosure, the functional part (103) is defined as a section for other components of the device (100) to be located. It is preferred that all components within the functional part (103) are accommodated within a housing for protecting the components. The functional part (103) is preferably located outside of the external auditory canal (112) to prevent occupying the external auditory canal (112). The functional components that are disposed at the functional part (103) of the device (100) includes a sound signal transmitting component used for transmitting the captured user's voice to be sent to the second communication device, and receiving the sound signals from the second communication device to be emitted by the sound emitting component. In short, the transmitting component is capable of transmitting and receiving digitized signals in between at least two physical locations, through wireless or wired technologies. The antenna is an example of a sound signal transmitting component.

Other than the sound signal transmitting component, an amplifier could also be added at the functional part (103) for amplifying sound signals received from the second communication device and/or the captured user's voice to be sent to the second communication device. With this amplifier, soft vocal sounds like whisperings captured by the sound capturing component could be amplified for the other person using the second communication device to receive the sound signals. Other components like a sound processor for altering the sound signals through audio effect or a sound filter are also applicable at the functional part for filtering noise to ensure clarity of the sound sent to or received from the second communication device.

In addition to the first barrier (104), a second barrier could be optionally incorporated to the device (100) at the opening of the external auditory canal (112) to occlude the canal (112) for blocking external sound waves from entering the external auditory canal (112), in particular preventing the external sound waves from propagating into the sound capturing region (109) and be captured by the sound capturing component so that it would not be picked up and sent to the communication gadget.

The first barrier (104) and the second barrier can be in the form of single or multiple layers or sections and is composed of a single type or various types of material in various states of matter, such as, but not limited to liquid, semi-liquid, solid, semi- solid, gaseous, capable of dampening sound or sound-proofing. The barriers can be applied as a singular unit or multiple units.

Figure 4, 5 and 6 illustrate the three main modes of use of the device (100) in association with associated gadgets (103). The associated gadget (103) which houses any one or combination of amplifier, antenna, battery, electronic circuitry, sound quality enhancers, the sound capturing component and/or the sound emitting component is disposed at the external of the ear and is connected to the device (100) via permanent or temporary affixations, wireless communication technologies or cable.

The associated gadget (103) could be part of the device (100) or a separate element from the device (100). It is any contraption, apparatus, device or construct used in association with the device (100) which could be connected via permanent or temporary affixations and/or attachments such that the associated gadget (103) becomes a permanent or temporary integral part of the device (100). The role of the transmitting means such as antenna inside the associated gadget (103) is to perform the function of transmitting the vocal sound waves to the communication gadget over the other end of a communication connection line and receiving sound signals of any communication gadget. The other components such as amplifier and sound quality enhancer enhance the quality of the sound waves in terms of clarity and audibility.

The associated gadget (103) can be a design and construct which is affixed to the device (100) permanently and/or is housed within a base gadget (115), whereby the associated gadget (103) is connected with the device via wireless technology such as, but not limited to, bluetooth, infra-red, or ultrasound; or using cables. One part of the associated gadget (103) could be attached to the device (100), whereas another part of the associated gadget (103) attached to the base gadget (115). The base gadget (115) is defined as an independent gadget that functions on its own even without the device (100), but can be connected to the device (100) using wireless technologies or cables to exploit the functionality of the device (100). Examples of base gadgets (115) are found in such fields as, but not limited to Information, Communication, and Telecommunication (ICT), military, medical, and aerospace. Examples of base gadgets are cellular phones; wearable cellular phones; walkie- talkies such as one-way radio or two-way radio handsets; hand-held devices; computers; information kiosks; and video-conferencing equipment.

An example where the device (100) is connected permanently to an associated gadget (103) is bluetooth handsfree headset. The bluetooth handsfree headset performs all the necessary functionalities to enable the vocal sound waves captured by sound capturing component to be transmitted to any communication gadget over the other end of the communication connection line, as well as enable sound signals received by the bluetooth handsfree headset received from the communication gadget to be emitted by the sound emitting component.

An example where the device (100) is connected wirelessly to the associated gadget (103) is a bluetooth pairing or synchronization of the device ( 100) affixed with a bluetooth modem with a mobile ICT or Information Communication Telecommunication gadget also having a Bluetooth modem.

An example of the device being connected via cables to the associated gadget (103) is a handsfree headset which uses the conventional audio cables with audio ports and audio jacks.

The device (100) places the two most important functions that are used in two-way communication - a sound emitting function and a sound capturing function — combined into one unit to fit into the external auditory canal (112). As design miniaturization technology is rapidly developing, the dimension of the device (100) might be reduced drastically such that it fits snugly in the external auditory canal (112). To prevent the device (100) from being inserted too deep into the external auditory canal (112), the facet of the device (100) that faces the pinna can be fashioned to have a larger girth than the facet of the device (100) that faces the tympanic membrane (111). This might also be advantageous for the second barrier to be disposed at or close to the outer end of the device facing the external environment to prevent or minimise undesired external environmental noise or ambient noise from getting into the auditory canal (112).

Although numerous structures, features and functions of various embodiments of the disclosure have been set forth in the foregoing description, it is understood that the exemplary embodiments of the preferred forms are not to be regarded as a departure from the invention and they may be modified within the scope of the appended claims.

Claims

1. A two-way communication device (100) for communicating with a communication gadget comprising

a housing disposed within the external auditory canal (112) of a user that is divided into a sound capturing part (101) which is positioned at a sound capturing region (109) within the external auditory canal (112) and a sound emitting part (102);

a sound capturing component associated with the sound capturing part (101) of the device for capturing vocal sound waves of the user to be transmitted to the communication gadget-that is propagated in the air within the sound capturing region (109) which is caused by vibrations along the walls (113) of the external auditory canal (112) and/or vocal sound waves of the user that are propagated directly from the walls of the external auditory canal (112) to be captured by the sound capturing part (101) when the user is producing vocal sound;

a sound emitting component associated with the sound emitting part (102) of the device (100) for emitting sound signals received from the communication gadget at a sound emitting region (110) within the external auditory canal (112) to be propagated to the tympanic membrane (111) of the ear;

wherein the sound waves emitted from the communication gadget is prevented to be captured by the sound capturing component by a first barrier (104) of the device (100) that is positioned within the external auditory canal (112) to separate the sound capturing region (109) and the sound emitting region (110).

2. A two-way communication device (100) according to claim 1, wherein the sound capturing component is either completely, partially or not positioned within the sound capturing part (101). A two-way communication device (100) according to claim 2, wherein the sound capturing component that is partially or not positioned within the sound capturing part (101) is connected to the sound capturing part (101) by an opening or channel such that the captured sound waves from the sound capturing region (109) enters the sound capturing part (101) and are directed to the sound capturing component through the opening or channel.

A two-way communication device (100) according to claim 1, wherein the sound emitting component is either completely, partially or not positioned within the sound emitting part (102).

A two-way communication device (100) according to claim 4, wherein the sound emitting component that is partially or not positioned within the sound emitting part (102) is connected to the sound emitting part (102) by a channel or opening for directing sound signals emitted from the sound emitting component to the sound emitting region (110).

A two-way communication device (100) according to claim 1, wherein the sound emitting part (102) is in the form of a channel or opening that is connected to the sound emitting component which is positioned partially or completely outside of the ear, and is extended through the first barrier (104) towards the sound emitting region (110) for allowing sound signals emitted from the sound emitting component to propagate into the sound emitting region (110).

A two-way communication device (100) according to claim 1, further comprising an associated gadget (103) disposed within the ear, at the external of the ear, or away from the ear which is connected to the device (100) via permanent affixations, permanent non-affixations, or temporary affixations, for housing any one or combination of an amplifier, antenna, battery, sound quality enhancers, the sound capturing component and/or the sound emitting component, and mechanical, electrical, and electronics functionalities.

A two-way communication device (100) according to claim 1, further comprising a second barrier positioned at the opening of the external auditory canal (112) to occlude the external auditory canal (112) for blocking external sound waves from entering the external auditory canal (112).

A two-way communication device (100) according to claim 1 or claim 8, wherein the first barrier (104) and/or second barrier is in the form of single or multiple layers or sections which is composed of any one or a combination of materials in the form of liquid, semi-liquid, solid, semi-sold, gaseous that are capable of dampening sound or sound-proofing.

A two-way communication device (100) according to claim 1, wherein the structure of the sound capturing part (101) and/or the sound emitting part (102) is formed by apertures, slits, physical walls in the form of a sponge or net, or perforated physical walls.

A two-way communication device (100) according to claim 1, wherein the sound capturing part (101) and/or the sound emitting part (102) has no physical wall and is integrated with the device (100) by virtue of certain skeletal frames that holds the sound capturing part (101) and/or the sound emitting part (102) to the device (100), or is free of any physical shape and form or free of any physical demarcation.

A two-way communication device (100) according to claim 1, wherein the sound capturing part (101) is fabricated in such a way that it fits closely and in direct contact to the walls (113) of the external auditory canal (112) in order to capture vocal sound waves propagated directly from the walls (113) of the external auditory canal (112) to the sound capturing part (101).