Call system

Abstract

To provide a communication system that supports communication between a plurality of speakers who are close to each other but separated by a simple barrier. [Solution] A communication system that assists conversation between two people facing each other through a shielding material in a space, includes a pair of communication units: a first communication unit that can be attached to the shielding material by sandwiching the shielding material between them, and a second communication unit that can be attached to the shielding material by sandwiching the shielding material between them. The first communication unit has a first microphone and a first speaker, and amplifies sound input from the first microphone and outputs it from the second speaker. The second communication unit has a second microphone and a second speaker, and amplifies sound input from the second microphone and outputs it from the first speaker. The shielding material has at least one hole 7 that penetrates both surfaces facing each other, and the first and second communication units are self-supportingly fixed to the shielding material through the hole.

Description

Technical Field

[0001] The present invention relates to a communication system, and more particularly to a communication system that supports conversations between speakers who are facing each other at a short distance.

Background Art

[0002] Conventionally, when a visitor and a responder have a conversation at a short distance at a ticket sales counter in an amusement park or a movie theater, at a window of an office or a station, or at a bank counter, etc., it is common to talk to each other in a loud voice because they are close to each other. On the other hand, in the above-mentioned sales counters, windows, counters, etc., the space of the responder may be a private room separated from the visitor, and in some cases, the space between the two is completely separated by a shielding object such as an acrylic plate. In such cases, since it may be difficult to hear each other even when they talk in a loud voice, a communication system may be provided to assist the conversation through the shielding object. Such a communication system generally includes, in addition to a main body placed in the space of the responder, a microphone and a speaker for the responder, and a microphone and a speaker for the visitor, and these are installed in the space of the responder and the space of the visitor, respectively. An example of such a communication system is disclosed in Patent Document 1 and Patent Document 2.

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to prevent droplet infection of infectious diseases such as influenza and COVID-19, in sales floors, windows, counters, etc. that were not originally completely separated by a shielding material, an environment may arise where a shielding material such as an acrylic plate is used to simply shield the responder and the visitor on the spot. Typically, a simple shielding material is selected from acrylic plates or transparent vinyl sheets sold at home centers, etc. in an appropriate size, or cut to an appropriate size, and installed immediately at a position to block between speakers in the manner of DIY (Do It Yourself: Sunday carpentry). In this way, when a simple shielding material is used to block a place where the speakers were not originally completely separated assuming conversation in a natural voice, it is difficult to assist the conversation between the speakers. Conventional call systems are based on a space design that completely separates the speakers from the beginning, and as described above, it requires laborious installation work such as separately installing a microphone and a speaker, which are separate from the main body, in the space of the responder and the space of the visitor respectively.

[0005] Focusing on the above problems, an object of the present invention is to provide a call system that supports calls between a plurality of speakers who are in close proximity to each other but are separated by a simple shielding material.

Means for Solving the Problems

[0006] The call system according to an embodiment of the present invention is a call system that assists conversation between two persons facing each other through a shielding material, and includes a pair of call units including a first unit that can be attached to the shielding material by sandwiching the shielding material, and a second call unit that can be attached to the shielding material by sandwiching the shielding material. The first call unit includes a first microphone and a first speaker, the second call unit includes a second microphone and a second speaker, and is configured to amplify the voice input from the first microphone and output it from the second speaker, and amplify the voice input from the second microphone and output it from the first speaker.

[0007] The communication system according to an embodiment of the present invention includes a mounting means for sandwiching the shielding material between the first communication unit and the second communication unit and mounting them on the shielding material. An example of the mounting means is a surface of the first housing of the first communication unit, which is different from the sound collection direction of the first microphone and the sound emission direction of the first speaker, and a surface of the second housing of the second communication unit, which is different from the sound collection direction of the second microphone and the sound emission direction of the second speaker, are connected and have an urging force inside. Another example of the mounting means is composed of a first magnet provided on a surface of the first housing of the first communication unit, which is different from the sound collection direction of the first microphone and the sound emission direction of the first speaker, and a second magnet or a metal element provided on a surface of the second housing of the second communication unit, which is different from the sound collection direction of the second microphone and the sound emission direction of the second speaker, and the first magnet and the second magnet are opposite poles to each other. Further, in another example of the mounting means, it includes a first mounting means for mounting the first communication unit through a hole provided in the shielding material and a second mounting means for mounting the second communication unit. The first mounting means has an extending portion extending from a surface of the first housing of the first communication unit, which is different from the sound collection direction of the first microphone and the sound emission direction of the first speaker. The second mounting means has a receiving portion provided on a surface of the second housing of the second communication unit, which is different from the sound collection direction of the second microphone and the sound emission direction of the second speaker, and can be fitted into the extending portion. By fitting the receiving portion into the extending portion through the hole in the shielding material, the first communication unit and the second communication unit are mounted on the shielding material. In addition, various modifications can be made to the communication system according to an embodiment of the present invention.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a communication system that supports communication between a plurality of speakers who are close to each other but separated by a simple shielding object.

Brief Description of the Drawings

[0009]

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DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 each show a call system 10 according to an embodiment. The call system 10 is installed in a space 1 where a responder and a visitor have a conversation, such as a ticket sales counter in an amusement park or a movie theater, a window at an office or a station, or a counter at a bank. An example of the space 1 is an open space originally assumed for the visitor 3 and the responder 4 to have a conversation with each other by voice. Here, a shielding material 2 is provided in the space 1 so as to physically block between the visitor 3 and the responder 4. The shielding material 2 is a member provided in the space 1 immediately and simply. An example of the shielding material 2 is an acrylic plate or a transparent vinyl sheet available at a home center or the like. As an example of the installation of the shielding material 2, columns are provided at both ends of the shielding material 2 or fixed to a pedestal so as to stand stably and independently, and as shown in FIG. 1, it is simply installed on a counter 5 between the visitor 3 and the responder 4. As another example of the installation of the shielding material 2, the shielding material 2 is fastened to the ceiling 6 of the space 1 with a drawing pin or double-sided tape or the like, or looped around a fixture on the ceiling 6, and installed so as to hang from the ceiling 6 onto the counter 5 as shown in FIG. 2. Here, the call system 10 has a pair of speakerphones that are detachable from the shielding material 2, and each speakerphone has a sound collection direction and a sound emission direction in a direction different from the direction facing the shielding material 2 when mounted on the shielding material 2. Preferably, one speakerphone has a sound collection direction and a sound emission direction in a direction D1 that is substantially opposite to the direction facing the shielding material 2 when mounted on the shielding material 2, and the other speakerphone has a sound collection direction and a sound emission direction in a direction D2 that is substantially opposite to the direction facing the shielding material 2 when mounted on the shielding material 2.

[0011] Figures 3 to 6 are diagrams showing an example of the call system 10. In this example, the call system 10 includes main bodies 12a and 12b in which a microphone and a speaker are housed in one housing. The main bodies 12a and 12b form a pair, with one being for visitors and the other for responders. The main bodies 12a and 12b are speakerphones in which the microphone and the speaker are integrated. Note that the main bodies 12a and 12b are collectively referred to as the main body 12. The call system 10 includes a support portion 11 for installing the main bodies 12a and 12b with a shielding material 2 sandwiched therebetween. The support portion 11 is provided between the main bodies 12a and 12b so as to suspend and support the main bodies 12a and 12b with the shielding material 2 sandwiched therebetween. As shown by the arrows A1 and A2 in Fig. 3, the support portion 11 is biased inward and has a kind of clip shape. On each of the main bodies 12, the support portion 11 is provided on the back surface, which is a surface of the housing that is substantially opposite to the sound collection direction and the sound emission directions (D1, D2). Due to the biasing force, the back surfaces of the main body 12a and the main body 12b are configured to attract each other.

[0012] An example of the specific structure of the support portion 11 includes a leaf spring. As shown in Fig. 6(a), the support portion 11 includes side portions 11b and 11c obtained by bending a leaf spring to the left and right, and a top portion 11a spanning between the side portion 11b and the side portion 11c. The side portion 11b and the side portion 11c are substantially line-symmetric with respect to a virtual axis X passing through the top portion 11a. As shown in Fig. 6(a), the support portion 11 can be formed by bending a leaf spring. By bending the leaf spring, the support portion 11 can be formed into a substantially arc shape or a U shape. The main body 12a is supported on the back surface at one end of the side portion 11b of the bent support portion 11, which is the end opposite to the top portion 11a (11b1 in the figure), and the main body 12b is supported on the back surface at one end of the side portion 11c of the bent support portion 11, which is the end opposite to the top portion 11a (11c1 in the figure). The user can widen the distance between the main bodies 12a and 12b by applying a force in the direction opposite to the biasing force by holding the ends 11b1 and 11c1 of the support portion 11 by hand and separating them from each other.

[0013] As shown in Fig. 6(b), an example of the specific structure of the support portion 11 includes two base plates 11f and 11g that respectively support the main bodies 12a and 12b, and a spring 11h sandwiched between the base plates 11f and 11g. One end of the base plate 11f (11f1 in the figure) supports the main body 12a on the back side, and one end of the base plate 11g (11g1 in the figure) supports the main body 12b on the back side. The spring 11h is, for example, a coil spring and has a biasing force with respect to the inside indicated by the arrows A1 and A2. As shown in Fig. 6(b), the spring 11h is provided sandwiched between the base plates 11f and 11g, and uses the other end (11f2 in the figure) of the base plate 11f on the side opposite to the one end 11f1 and the other end (11g2 in the figure) of the base plate 11g on the side opposite to the one end 11g1 as the force points, the spring 11h as the fulcrum, and the one end 11f1 of the base plate 11f and the one end 11g1 of the base plate 11g as the action points, and is configured such that forces are applied in the direction opposite to the biasing force so that both ends are separated from each other. By doing so, the distance between the main bodies 12a and 12b can be increased.

[0014] As shown in Fig. 4, in the communication system 10, the user can widen the distance between the main bodies 12a and 12b via the support portion 11 and insert the main body 12 so as to sandwich the shielding material 2. Then, when the user releases the force against the biasing force of the support portion 11, as shown in Fig. 5, the main body 12 sandwiches the shielding material 2 and is self-standing and fixed with the backs of each other facing each other. The configuration of fixing the main body 12 to the shielding material 2 by sandwiching the shielding material 2 with the support portion 11 in this way is particularly preferable when, as shown in Fig. 1, the shielding material 2 is installed on the counter 5 and the upper part of the shielding material 2 is open.

[0015] FIG. 7 is a diagram showing another example of the call system 10. In this example, the call system 10 includes main bodies 12a and 12b in which a microphone and a speaker are housed in one casing. The main bodies 12a and 12b form a pair, and one is used for a visitor and the other is used for a responder. The main bodies 12a and 12b are speakerphones in which a microphone and a speaker are integrated. The main bodies 12a and 12b are collectively referred to as the main body 12. The call system 10 includes a magnet 15 on the back surface of at least one of the main bodies 12a and 12b, and a magnet 15 or a metal part 16 on the back surface of the other, and the back surfaces are adsorbed by the magnetic force of the magnet 15. When magnets 15 are provided on the back surfaces of both the main bodies 12a and 12b, they may have opposite magnetic poles. One may be a magnet with an N pole and the other may be a magnet with an S pole so that the magnets 15 are adsorbed to each other. The magnet 15 is selected from magnets having a magnetic force such that the back surfaces of the main bodies 12a and 12b can be adsorbed with the shielding material 2 interposed therebetween. With such a configuration, the main bodies 12a and 12b can be self-standing and fixed in a form in which their back surfaces face each other with the shielding material 2 interposed therebetween by bringing the back surfaces of the main bodies 12a and 12b closer to each other across the shielding material 2. The magnet 15 and the metal part 16 may be provided at any location on the back surface of the main body 12, but it is a preferred example that they are provided at the center of gravity position of the main body 12 (for example, the substantially central position of the back surface), or when the back surface is rectangular, they are provided at the four corners (the four corners, that is, the four corners) respectively.

[0016] As shown in FIGS. 3 to 7, by using the support part 11 and the magnet 15, as shown in FIG. 8, the main bodies 12a and 12b can be fixed so as to stand on the shielding material 2 in a form in which their back surfaces face each other with the shielding material 2 interposed therebetween, and can be easily removed. In this state, the sound collection direction and the sound emission direction of the main body 12a face the speaker 3 (D1), and the sound collection direction and the sound emission direction of the main body 12b face the speaker 4 (D2).

[0017] As a modification of the example using the magnet 15 shown in FIG. 7, the main body 12 may be sandwiched between the shielding materials 2 and self-fixed using an accessory corresponding to the magnet 15 or the metal 16 provided on the back surface of the main body 12. FIG. 9 shows an example of self-fixing the main body 12 between the shielding materials 2 using the accessory 17. In this example, the communication system 10 includes magnets 15 or metal parts 16 on the back surfaces of the main bodies 12a and 12b respectively, and an accessory 17 corresponding to the magnet 15 or the metal part 16. The accessory 17 is a portable item provided separately from the main body 12 and is provided as an accessory of the main body 12. The accessory 17 also consists of a magnet or a metal part and is adapted to be attracted by magnetic force to the magnet 15 or the metal part 16. When the main body 12 has a magnet 15 on its back surface, the accessory 17 may be a metal part or have a magnet with a magnetic pole opposite to that of the magnet 15. When the main body 12 has a metal part 16 on its back surface, the accessory 17 may have a magnet. The accessory 17 may be substantially the same size as the corresponding magnet 15 or metal part 16. By using the accessory 17, as shown in FIG. 10, the main bodies 12a and 12b can be independently self-fixed to the shielding material 2. That is, instead of facing the back surfaces of the main bodies 12 towards each other and sandwiching the shielding material 2 and attracting each other, as shown in FIG. 10, each of the main bodies 12a and 12b can be fixed to the shielding material 2 using the accessory 17. While making the back surface of the main body 12a abut against the shielding material 2 so that the sound collection direction and the sound emission direction face the speaker 3 (D1), sandwich the shielding material 2 and attract the accessory 17 and the magnet 15 or the metal part 16 from the opposite side, whereby the main body 12a is self-fixed to the shielding material 2. Similarly, while making the back surface of the main body 12b abut against the shielding material 2 so that the sound collection direction and the sound emission direction face the speaker 4 (D2), sandwich the shielding material 2 and attract the accessory 17 and the magnet 15 or the metal part 16 from the opposite side, whereby the main body 12b is self-fixed to the shielding material 2. The main bodies 12a and 12b are self-fixed in a form facing the accessory 17 at the back respectively, and the main bodies 12 are fixed separately and spaced apart from each other.

[0018] FIG. 11 is a diagram showing an example of the configuration of the call system 10. In this example, the call system 10 includes an amplifier device 50 having a housing independent of the main body 12. The amplifier device 50 is a device that receives voice from one of the main bodies 12a and 12b, amplifies it, and transmits it to the other. That is, the amplifier device 50 amplifies the voice received from the main body 12a and transmits it to the main body 12b, and amplifies the voice received from the main body 12b and transmits it to the main body 12a. The main body 12a is provided with a microphone 20 and a speaker 21 inside the housing, but does not have an amplifier and a power supply for amplifying the voice picked up by the microphone 20. The main body 12b is provided with a microphone 30 and a speaker 31 inside the housing, but does not have an amplifier and a power supply for amplifying the voice picked up by the microphone 30. The amplifier device 50 includes an amplifier 51 and a power supply 52. The amplifier 51 is an audio amplifier that amplifies and outputs the input voice signal. The power supply 52 generates and outputs the power for driving the main body 12 from the commercial power supply. The main body 12 and the amplifier device 50 are connected to each other via a voice transmission medium 40 and a power transmission medium 41. The voice transmission medium 40 is a transmission medium for transmitting and receiving voice between the amplifier device 50 and the main body 12. The voice transmission medium 40 between the main body 12a and the amplifier device 50 may be referred to as the first voice transmission medium 40, and the voice transmission medium 40 between the main body 12b and the amplifier device 50 may be referred to as the second voice transmission medium 40. The voice transmission medium 40 may be a physical cable or a wireless communication medium such as NFC (Near Field Communication), Bluetooth, or wireless LAN. The power transmission medium 41 is a transmission medium for transmitting the power generated by the power supply 52 from the amplifier device 50 to the main body 12. The power transmission medium 41 between the main body 12a and the amplifier device 50 may be referred to as the first power transmission medium 41, and the power transmission medium 41 between the main body 12b and the amplifier device 50 may be referred to as the second power transmission medium 41. The power transmission medium 41 may be a physical cable or a wireless power transmission medium. The voice transmission medium 40 and the power transmission medium 41 may be a cable capable of transmitting a voice signal and power with one cable, such as a cable corresponding to phantom power (phantom cable).In the case of a phantom cable, the amplifier device 50 includes at least two cable terminals corresponding to the main bodies 12a and 12b, and is connected by a single cable independently of each of the main bodies 12a and 12b. The voice picked up by the microphone 20 of the main body 12a is input to the amplifier device 50 via the voice transmission medium 40, amplified by the amplifier 51, transmitted to the main body 12b via the voice transmission medium 40, and output from the speaker 31 of the main body 12b. The voice picked up by the microphone 30 of the main body 12b is input to the amplifier device 50 via the voice transmission medium 40, amplified by the amplifier 51, transmitted to the main body 12a via the voice transmission medium 40, and output from the speaker 21 of the main body 12a. When the voice transmission medium 40 is a wireless communication medium, the main body 12 includes a wireless communication circuit (not shown) inside the housing, and the housing of the amplifier device 50 also includes a corresponding wireless communication circuit (not shown), and wireless communication is established by both wireless communication circuits. When the voice transmission medium 40 is a wireless communication medium, the voice transmission medium 40 has a wireless communication range in which wireless communication can be performed when the main body 12 is attached to the shielding material 2 and the amplifier device 50 is placed on the counter 5. When the power transmission medium 41 is a wireless power transmission medium, the main body 12 includes a wireless power receiving circuit (not shown) inside the housing, and the housing of the amplifier device 50 includes a corresponding wireless power transmission circuit (not shown), and wireless power transmission is established by the power receiving circuit and the power transmission circuit. When the power transmission medium 41 is a wireless power transmission medium, the power transmission medium 41 has a wireless power transmission range in which wireless power transmission is possible when the main body 12 is attached to the shielding material 2 and the amplifier device 50 is placed on the counter 5.

[0019] FIG. 12 is a diagram showing another example of the configuration of the communication system 10. This example is similar to the example shown in FIG. 11 in that the communication system 10 includes an amplifier device 50 having a housing independent of the main body 12. However, in this example, only one of the main bodies 12a and 12b is connected to the amplifier device 50, and the main bodies 12 are connected to each other. Here, an example in which only the main body 12a is connected to the amplifier device 50 will be described. As shown in FIG. 12, the main body 12a is connected to the amplifier device 50 via an audio transmission medium 40 (40a) and a power transmission medium 41 (41a). The main body 12a and the main body 12b are connected to each other via another audio transmission medium 40 (40b) and a power transmission medium 41 (41b). The sound picked up by the microphone 20 of the main body 12a is input to the amplifier device 50 via the audio transmission medium 40a, amplified by the amplifier 51, returned to the main body 12a via the audio transmission medium 40a, and then input from the main body 12a to the main body 12b via the audio transmission medium 40b and output from the speaker 31. The sound picked up by the microphone 30 of the main body 12b is input from the main body 12b to the main body 12a via the audio transmission medium 40b, then input from the main body 12a to the amplifier device 50 via the audio transmission medium 40a, amplified by the amplifier 51, and finally returned to the main body 12a via the audio transmission medium 40a and output from the speaker 21. In this way, the sound picked up by the microphone 20 of the main body 12a is amplified and output via the audio transmission medium 40a, and the sound picked up by the microphone 30 of the main body 12b is amplified and output via the audio transmission media 40a and 40b. Also, the power generated by the power supply 52 is supplied to the main body 12a via the power transmission medium 41a and used to drive the electrical elements in the main body 12a, while being supplied from the main body 12a to the main body 12b via the power transmission medium 41b and used to drive the electrical elements in the main body 12b.

[0020] FIG. 13 is a diagram showing another example of the configuration of the call system 10. In this example, in the call system 10, the main bodies 12a and 12b directly amplify and transmit voices to each other. In addition to the microphones 20 and speakers 21 described above, the main body 12a includes an amplifier 22 and a power supply 23 inside the housing. The amplifier 22 amplifies the voice picked up by the microphone 20. The power supply 23 supplies power to the electrical elements such as the amplifier 22 inside the main body 12a. In addition to the microphones 30 and speakers 31 described above, the main body 12b includes an amplifier 32 and a power supply 33 inside the housing. The amplifier 32 amplifies the voice picked up by the microphone 30. The main body 12a transmits the voice amplified by the amplifier 22 to the main body 12b. The main body 12b transmits the voice amplified by the amplifier 32 to the main body 12a. The power supply 33 supplies power to the electrical elements such as the amplifier 32 inside the main body 12b. The power supplies 23 and 33 may each generate power from a commercial power supply, or may be batteries such as secondary batteries. The main body 12a and the main body 12b are directly connected to each other via a voice transmission medium 40. As described above, the voice transmission medium 40 may be a physical cable, or may be a wireless communication medium such as NFC, Bluetooth, or wireless LAN. When the voice transmission medium 40 is a wireless communication medium, the main body 12 is provided with a wireless communication circuit (not shown) inside the housing, and the housing of the amplifier device 50 is also provided with a corresponding wireless communication circuit (not shown), and wireless communication is established by both wireless communication circuits. When the voice transmission medium 40 is a wireless communication medium, the voice transmission medium 40 has a wireless communication range in which wireless communication can be performed between the main bodies 12 when the main bodies 12 are each mounted on the shielding material 2. As shown in FIG. 7, when the main bodies 12 are mounted facing each other via the shielding plate 2 by magnetic force, when the voice transmission medium 40 is a wireless communication medium, the wireless communication range of the voice transmission medium 40 is set to be equal to or wider than the action range of the magnetic force.

[0021] FIG. 14 is a diagram showing another example of the configuration of the communication system 10. This example is similar to the example shown in FIG. 13 in that the main bodies 12a and 12b directly amplify and transmit voices to each other. However, in this example, only one of the main bodies 12a and 12b has a power supply, and the other does not. Here, an example will be described in which the main body 12a has a power supply (power supply 23), but the main body 12b does not have a power supply. As shown in FIG. 14, the main bodies 12a and 12b are connected to each other via a voice transmission medium 40a and a power transmission medium 41. The power generated by the power supply 23 in the main body 12a is used to drive the electrical elements in the main body 12a, while being transmitted to the main body 12b via the power transmission medium 41 and used to drive the electrical elements in the main body 12b.

[0022] FIGS. 15 to 28 are diagrams showing another example of the communication system 10. The communication system 10 includes main bodies 12a and 12b in which a microphone and a speaker are housed in one housing. The main body 12a and the main body 12b form a pair, and one is used for a visitor and the other is used for a responder. The main bodies 12a and 12b are speakerphones in which a microphone and a speaker are integrated. The main bodies 12a and 12b are collectively referred to as the main body 12. In this example, the communication system 10 is configured to attach the main bodies 12a and 12b to the shielding material 2 through holes provided in the shielding material 2. As shown in FIG. 15, one or more holes 7 are provided in the shielding material 2. The holes 7 are provided so as to penetrate both surfaces of the shielding material 2 that face the speakers 3 and 4 (that is, both surfaces to which the main body 12 is attached). The holes 7 may be holes provided in advance by the manufacturer of the shielding material 2, or may be holes drilled in the shielding material 2 by the installer of the communication system 10 using a drill or the like for DIY. As shown in FIG. 16, the back surface of the main body 12a is self-standingly fixed to the shielding material 2 through the holes 7, and the back surface of the main body 12b is self-standingly fixed to the shielding material 2 through the holes 7. The structure for self-standing fixation through the holes 7 will be described in detail below.

[0023] FIG. 17 shows an example of a structure for self-standing fixation of the main body 12 to the shielding material through the hole 7. As shown in FIG. 17, one side of the main body 12 (main body 12a in the example of FIG. 17) has an extension portion 65 extending from the back surface on the back surface, and the other side of the main body 12 (main body 12b in the example of FIG. 17) has a receiving portion 66 corresponding to the extension portion 65 on the back surface. The extension portion 65 extends from the back surface of the main body 12a in the back surface direction (a direction substantially opposite to the sound collection direction and the sound emission direction D1), and has a terminal end that is the end where the extension ends. The receiving portion 66 corresponds to the extension portion 65 and has a shape into which the extension portion 65 fits. Specifically, the receiving portion 66 has a depth and a shape into which a part including the terminal end of the extension portion 65 fits. The extension length from the back surface to the terminal end of the extension portion 65 is at least longer than the width of the shielding material 2 (the distance between both openings of the hole 7). Preferably, the extension length of the extension portion 65 has a length that is at least the sum of the width of the shielding material 2 and the depth of the receiving portion 66. The extension portion 65 may be formed of the same material as the housing of the main body 12a or may be formed of a different material.

[0024] The extension portion 65 and the receiving portion 66 are fitted in a male-female relationship. As an example, the extension portion 65 includes a male screw, and the receiving portion 66 includes a female screw. Among the extension portion 65, a male screw is formed over at least a predetermined length from the terminal end, and the receiving portion 66 preferably has a depth corresponding to the length of this male screw portion. With such a configuration, the receiving portion 66 is fitted into the extension portion 65 by screwing the male screw and the female screw. As another example, as shown in FIG. 18, the extension portion 65 includes a male plug 68 for making an electrical connection, and the receiving portion 66 includes a female jack 69 corresponding to the plug. Among the extension portion 65, at least a portion of a predetermined length from the terminal end includes the plug 68. The plug 68 may be a plug that functions as an audio transmission medium 40 and / or a power transmission medium 41, such as a 2-pole phone plug (TS plug), a 3-pole phone plug (TRS plug), a 4-pole phone plug (TRSS plug), or a plug for a phantom cable.

[0025] Insert the extension part 65 of the main body 12a into the hole 7 from one side of the surface of the shielding material 2, project the extension part 65 from the other side of the surface of the shielding material 2, and fit the receiving part 66 onto the projected extension part 65, whereby the main bodies 12a and 12b can be self-standingly fixed to the shielding material 2 in such a manner that their backs face each other. FIGS. 19 to 20 are views showing a state in which the main bodies 12a and 12b are self-standingly fixed to the shielding material 2. Through the hole 7 of the shielding material 2, the receiving part 66 of the main body 12b fits into the extension part 65 of the main body 12a, whereby both main bodies 12 are self-standingly fixed to the shielding material 2 with their backs facing each other.

[0026] When the extension part 65 includes the plug 68 and the receiving part 66 includes the jack 69, voice or power may be transmitted between the main bodies 12 through the electrical connection between the plug 68 and the jack 69. In the example shown in FIG. 21, as shown in FIG. 13, the main bodies 12 are respectively provided with microphones (20, 30), speakers (21, 31), amplifiers (22, 32), and power supplies (23, 33). The plug 68 and the jack 69 function as the voice transmission medium 40. Through the electrical connection between the plug 68 and the jack 69, the voice picked up by the microphone 20 of the main body 12a and amplified by the amplifier 22 is transmitted to the main body 12b and output from the speaker 31, while the voice picked up by the microphone 30 of the main body 12b and amplified by the amplifier 32 is transmitted to the main body 12a and output from the speaker 21. Further, in the example shown in FIG. 22, as shown in FIG. 14, the main body 12a includes a power supply 23 in addition to the microphone 20, the speaker 21, and the amplifier 22, while the main body 12b includes the microphone 30, the speaker 31, and the amplifier 32 but does not include a power supply. The plug 68 and the jack 69 function as the voice transmission medium 40 and the power transmission medium 41. In addition to voice transmission being performed through the electrical connection between the plug 68 and the jack 69 as shown in FIG. 21, the power generated by the power supply 23 is supplied from the main body 12a to the main body 12b through this electrical connection. Further, in the example shown in FIG. 23, as shown in FIG. 11, the main body 12a and the amplifier device 50 are connected through the voice transmission medium 40a and the power transmission medium 41a, and the main body 12a and the main body 12b are connected through the electrical connection between the plug 68 and the jack 69. The plug 68 and the jack 69 function as the voice transmission medium 40b and the power transmission medium 41b. The voice picked up by the microphone 20 is input to the amplifier device 50 through the voice transmission medium 40a and amplified by the amplifier 51, then returns to the main body 12a through the voice transmission medium 40a, is transmitted to the main body 12b through the electrical connection between the plug 68 and the jack 69, and is output from the speaker 31. The voice picked up by the microphone 30 is transmitted to the main body 12a through the electrical connection between the plug 68 and the jack 69, is input from the main body 12a to the amplifier device 50 through the voice transmission medium 40a and amplified by the amplifier 51, then returns to the main body 12a through the voice transmission medium 40a, and is output from the speaker 21.

[0027] As a modification of the example shown in FIGS. 17 to 18, each of the main bodies 12a and 12b may be provided with an extension portion 65 and a receiving portion 66. When connecting the main bodies 12a and 12b with a single extension portion 65 and receiving portion 66, as shown in FIGS. 21 to 23, voice must be transmitted bidirectionally through this extension portion 65 and receiving portion 66. To perform full-duplex transmission, it may be necessary to double the electrodes for voice transmission and form them on the extension portion 65 (plug 68). On the other hand, if an extension portion 65 and a receiving portion 66 are provided for each of the main bodies 12a and 12b, and the voice transmission from the main body 12a to the main body 12b and the voice transmission from the main body 12b to the main body 12a are through different paths via their respective extension portions 65 and receiving portions 66, the electrodes formed on one extension portion 65 (plug 68) for voice transmission can be reduced. FIG. 24 shows an example in which each of the main bodies 12 is provided with an extension portion 65 and a receiving portion 66. The main bodies 12a and 12b each have an extension portion 65 and a receiving portion 66 at the same position on the back in the same way. Thus, the backs of the main bodies 12 can face each other, and while fitting the receiving portion 66 of the main body 12b into the extension portion 65 of the main body 12a, the receiving portion 66 of the main body 12a can be fitted into the extension portion 65 of the main body 12b, and the main body 12 can be connected by the two extension portions and the receiving portion 66. In this example, the extension portion 65 of the main body 12a is inserted into the first hole 7 from one side of the surface of the shielding material 2, the extension portion 65 is protruded from the other side of the surface of the shielding material 2, the receiving portion 66 of the main body 12b is fitted into the protruded extension portion 65, and while inserting the extension portion 65 of the main body 12b into the second hole 7 adjacent to the first hole 7 from the other side of the surface of the shielding material, the extension portion 65 is protruded from one side of the surface of the shielding material 2, and the receiving portion 66 of the main body 12a is fitted into the protruded extension portion 65, whereby the main bodies 12a and 12b can be self-standingly fixed to the shielding material 2 with their backs facing each other. In this example, the voice transmission from the main body 12a to the main body 12b is preferably performed through the connection between the extension portion 65 of the main body 12a and the receiving portion 66 of the main body 12b (the electrical connection between the plug 68 of the main body 12a and the jack 69 of the main body 12b), and the voice transmission from the main body 12b to the main body 12a is preferably performed through the connection between the extension portion 65 of the main body 12b and the receiving portion 66 of the main body 12a (the electrical connection between the plug 68 of the main body 12b and the jack 69 of the main body 12a).In this example, the power transmission from the main body 12a to the main body 12b may be performed via the connection between the extension part 65 of the main body 12a and the receiving part 66 of the main body 12b (the electrical connection between the plug 68 of the main body 12a and the jack 69 of the main body 12b).

[0028] As a modification of the example using the extension part 65 shown in FIG. 17, an accessory corresponding to the extension part 65 provided on the back surface of the main body 12 may be used to sandwich the main body 12 between the shielding materials 2 and fix it independently. FIG. 25 shows an example of independently fixing the main body 12 to the shielding material 2 using the accessory 70. In this example, the communication system 10 includes extension parts 65 provided on the back surfaces of the main bodies 12a and 12b, respectively, and an accessory 70 corresponding to the extension part 65. The accessory 70 is a portable item provided separately from the main body 12 and is provided as an accessory of the main body 12. The accessory 70 has a receiving part 70a into which the end of the extension part 65 fits and has the same configuration as the above-described receiving part 66. By using the accessory 70, as shown in FIG. 26, the main bodies 12a and 12b can be independently and self-supportingly fixed to the shielding material 2. That is, instead of facing the back surfaces of the main bodies 12 to sandwich the shielding material 2 and connecting them with the extension part 65 and the receiving part 66, as shown in FIG. 25, each of the main bodies 12a and 12b can be fixed to the shielding material 2 by fitting the respective extension part 65 and the accessory 70. By inserting the extension part 65 of the main body 12a into the hole 7 from one surface of the shielding material 2, protruding the extension part 65 from the other surface of the shielding material 2, and fitting the receiving part 70a of the accessory 70 into the protruding extension part 65, the main body 12a is self-supportingly fixed to the shielding material 2. Similarly, by inserting the extension part 65 of the main body 12b into the hole 7 from the other surface of the shielding material 2, protruding the extension part 65 from one surface of the shielding material 2, and fitting the receiving part 70a of the accessory 70 into the protruding extension part 65, the main body 12b is self-supportingly fixed to the shielding material 2. The main bodies 12a and 12b are self-supportingly fixed in a form facing the accessory 70 at the back, respectively, and the main bodies 12 are fixed separately and spaced apart.

[0029] As another form of utilization of the hole 7 provided in the shielding plate 2, when the audio transmission medium 40 and the power transmission medium 41 are cables, as shown in FIGS. 27 to 28, the cables may be passed through the hole 7 and the main body 12 and the amplifier device 50 may be configured to be connected. As shown in FIG. 27, the amplifier device 50 has individual plugs 40p (41p) corresponding to the main bodies 12a and 12b, respectively. Each cable 40 (41) extending from the amplifier device 50 has a plug 40p (41p) similar to the plug 68 described above. On the back surface of each of the main bodies 12a and 12b, there is a receiving portion 71 corresponding to the plug 40p (41p), similar to the receiving portion 66 described above. As shown in FIG. 28, the back surface of the main body 12a is brought into contact with the shielding material 2 so that the sound collection direction and the sound emission direction face the speaker 3 (D1), the receiving portion 71 of the main body 12a is exposed through the first hole 7, and one plug 40p (41p) is connected to the receiving portion 71 from the opposite side of the shielding material 2. Similarly, the back surface of the main body 12b is brought into contact with the shielding material 2 so that the sound collection direction and the sound emission direction face the speaker 4 (D2), the receiving portion 71 of the main body 12b is exposed through the second hole 7 spaced apart from the first hole 7, and the other plug 40p (41p) is connected to the receiving portion 71 from the opposite side of the shielding material 2. By doing so, the main body 12 and the amplifier device 50 can be connected via the cables 40 (41) through the two holes 7.

[0030] In the housing of the main body 12, the microphones 20 and 30 and the speakers 21 and 31 are such that the sound collection directions of the former and the sound emission directions of the latter are substantially the same (D1, D2). Therefore, it is easy for sound to loop between the microphones 20 and 30 and the speakers 21 and 31 and for howling to occur. Thus, in order to suppress the occurrence of howling, the directivity of the speakers 21 and 31 is adjusted so that the sound output from the speakers 21 and 31 is not collected by the microphones 20 and 30 as much as possible. Specifically, as shown in FIG. 29, in the main body 12, the speakers 21 and 31 are composed of a plurality of speaker units arranged in an array in the vertical direction when viewed from the sound emission directions (D1, D2), and the microphones 20 and 30 are arranged along this array direction (D3 in the figure). That is, the microphones 20 and 30 are arranged at positions spaced apart along the array direction D3 from the ends of the speakers 21 and 31 in the array direction D3. With such a configuration, the speakers 21 and 31 become line sound sources due to the array effect, the directivity weakens in the array direction D3, and by arranging the microphones 20 and 30 on the extension line of the array direction D3 where the directivity has weakened, it is possible to suppress the sound output from the speakers 21 and 31 from being collected by the microphones 20 and 30.

[0031] When the main bodies 12a and 12b are fixed with the shielding plate 2 sandwiched therebetween and facing each other back to back, the vibration of one main body 12 may be transmitted to the shielding material 2, and this vibration may be picked up by the microphone (microphone 20 or 30) of the other main body 12, causing howling. To prevent this, it is preferable to provide a vibration-absorbing material that absorbs vibration or a vibration-damping material that prevents vibration on the back surface of each of the main bodies 12a and 12b. The vibration-absorbing material or vibration-damping material is preferably composed of a member having cushioning properties such as sponge or rubber. The vibration-absorbing material or vibration-damping material may be provided over substantially the entire back surface so as to be exposed on the outer side of the back surface of the main body 12. The vibration-absorbing material or vibration-damping material may be provided at the four corners (the four sides) of the back surface so as to be exposed on the outer side of the back surface of the main body 12. The vibration-absorbing material or vibration-damping material may be provided on the part of the back surface of the main body 12 excluding the position where the magnet 15 or the metal part 16 is arranged so as to expose the magnet 15 or the metal part 16. The vibration-absorbing material or vibration-damping material may be provided to cover the magnet 15 or the metal part 16 on the back surface of the main body 12. In this case, the magnet 15 is selected from those having a magnetic force sufficient to adsorb to the corresponding magnet 15, metal part 16, or accessory 17 through at least the vibration-absorbing material or vibration-damping material provided on the main body 12 and the shielding material 2. Further, the vibration-absorbing material or vibration-damping material may be provided on the part of the back surface of the main body 12 excluding the position where the extension part 65 or the receiving part 66 is arranged. Further, the vibration-absorbing material or vibration-damping material may be provided on the part of the back surface of the main body 12 excluding the position where the receiving part 71 is arranged. FIG. 30 shows an example in which the main body 12 abuts against the shielding material 2 at one end (lower end) of the back surface and is self-fixed using the support part 11. In this case, a vibration-absorbing material or vibration-damping material 60 is provided at one end of the back surface that abuts against the shielding material 2 (60a provided at one end of the back surface of the main body 12a that abuts against the shielding material 2 and 60b provided at one end of the back surface of the main body 12b that abuts against the shielding material 2). FIG. 31 shows an example in which the main body 12 abuts against the shielding material 2 at substantially the entire back surface (substantially the entire surface) using the magnet 15 and is self-fixed. In this case, a vibration-absorbing material or vibration-damping material 60 (60a and 60b) is provided on the part of the back surface that abuts against the shielding material 2 excluding the part where the magnet 15 or the metal part 16 is provided.FIG. 32 shows another example in which the main body 12 is self-standing and fixed by contacting the shielding material 2 over substantially the entire back surface (substantially the entire surface) using the magnet 15. In this case, the magnet 15 or the metal part 16 is provided over substantially the entire back surface that contacts the shielding material 2. In the example shown in FIG. 32, the vibration-absorbing material or the vibration-damping material 60 is provided on the rearmost side, and the magnet 15 or the metal part 16 is provided inside thereof. FIG. 33 shows an example in which the main body 12 is self-standing and fixed by contacting the shielding material 2 over substantially the entire back surface (substantially the entire surface) using the extension part 65 and the receiving part 66. In this case, the vibration-absorbing material or the vibration-damping material 60 (60a and 60b) is provided on the part of the back surface that contacts the shielding material 2 other than the part where the extension part 65 and the receiving part 66 are provided. FIG. 34 shows an example in which, in the configuration of fixing the main body 12 to the shielding material 2 using the magnet 15, the vibration-absorbing material or the vibration-damping material 60 as rubber feet is provided at the four corners (four sides) of the back surface of the main body 12. In this case, since a predetermined gap is generated between the main body 12 and the shielding material 2 by the rubber feet 60, the magnet 15 is at least through the gap generated by the rubber feet 60 of the main body 12a, the gap generated by the rubber feet 60 of the main body 12b, and the shielding material 2, and is selected from those having a magnetic force sufficient to attract the corresponding magnet 15, metal part 16, or accessory 17.

[0032] In the communication system 10, the voice picked up by the microphone 20 of the main body 12a is output from the speaker 31 of the main body 12b, but this voice may be picked up by the microphone 30 of the main body 12b and output from the speaker 20 of the main body 12a. The reverse is also true. When the voice loops between the main body 12a and the main body 12b in this way, there is a risk of acoustic echo or howling. For this reason, the communication system 10 uses a voice switch to turn on / off the microphones 20 and 30, so that the microphone 20 or the microphone 30 of the main body 12a or 12b on the speaker side that is speaking is turned on, and the microphone 20 or the microphone 30 of the main body 12a or 12b on the listener side that is not speaking is turned off. As shown in FIG. 35, the main body 12a is provided with a voice switch 24, and the main body 12b is provided with a voice switch 34. The voice switch 24 monitors the voice level of the voice picked up by the microphone 20 (the voice input from the microphone 20), compares it with a threshold value (the first on-threshold value), and when a voice having a voice level equal to or higher than the first on-threshold value is input, turns on the output from the microphone 20 so that the voice picked up by the microphone 20 is output. It is an electronic switch. In addition, after once turning on the output from the microphone 20, the voice switch 24 continues to monitor the voice level of the voice input from the microphone 20, compares it with a threshold value (the first off-threshold value), and when the voice level of the voice input for a predetermined time (the second off-threshold value) or more is equal to or lower than the first off-threshold value (that is, when the substantially silent state continues for a predetermined time or more), turns off the output from the microphone 20 so that the voice picked up by the microphone 20 is not output. In addition, the voice switch 24 monitors the voice level of the voice input to the speaker 21 (the voice input from the microphone 30 of the main body 12b and transmitted through the voice transmission medium 40), and when there is a voice level equal to or higher than the threshold value (the second on-threshold value), even if the condition of the first on-threshold value is satisfied, the output of the microphone 20 may not be turned on.Similarly, the voice switch 34 monitors the voice level of the voice picked up by the microphone 30 (the voice input from the microphone 30), compares it with a threshold value (first on-threshold value), and when a voice having a voice level equal to or higher than the first on-threshold value is input, turns on the output from the microphone 30 so that the voice picked up by the microphone 30 is output. Further, after once turning on the output from the microphone 30, the voice switch 34 continues to monitor the voice level of the voice input from the microphone 30, compares it with a threshold value (first off-threshold value), and when the voice level of the voice input over a predetermined time (second off-threshold value) is equal to or lower than the first off-threshold value (that is, when a substantially silent state continues for a predetermined time or more), turns off the output from the microphone 30 so that the voice picked up by the microphone 30 is not output. Further, the voice switch 34 monitors the voice level of the voice input to the speaker 31 (the voice input from the microphone 20 of the main body 12a and transmitted via the voice transmission medium 40), and when there is a voice level equal to or higher than a threshold value (second on-threshold value), even if the condition of the first on-threshold value is satisfied, the output of the microphone 30 may not be turned on.

[0033] Furthermore, the call system 10 may be provided with a changing means for changing the operation parameters (first on-threshold value, second on-threshold value, first off-threshold value, second off-threshold value) of the voice switches 24 and 34, so that the operation parameters can be changed as appropriate. As an example, as shown in FIG. 36, the main body 12a is provided with a switch 25. The switch 25 is a manual switch such as a DIP switch and is operated by the user of the call system 10. The switch 25 is connected to the voice switch 24, and the voice switch 24 changes the operation parameters according to the operation of the switch 25. For example, the voice switch 24 holds a plurality of combinations of the first on-threshold value, the second on-threshold value, the first off-threshold value, and the second off-threshold value, and turns on / off the voice output of the microphone 20 using the combination selected according to the operation of the switch 25. For example, the voice switch 24 has a first threshold combination having a lower first on-threshold value and a longer second off-threshold value so as to more easily turn on the output of the microphone 20, and a second threshold combination having a higher first off-threshold value and a shorter second off-threshold value so as to more difficultly turn on the output of the microphone 20, and turns on / off the voice output of the microphone 20 using either the first threshold combination or the second threshold combination according to the operation of the switch 25. Similarly, the main body 12b is provided with a switch 35. The switch 35 is a manual switch such as a DIP switch and is operated by the user of the call system 10. The switch 35 is connected to the voice switch 34, and the voice switch 34 changes the operation parameters according to the operation of the switch 35. For example, the voice switch 34 holds a plurality of combinations of the first on-threshold value, the second on-threshold value, the first off-threshold value, and the second off-threshold value, and turns on / off the voice output of the microphone 30 using the combination selected according to the operation of the switch 35.For example, the voice switch 34 holds a first threshold combination having a lower first on-threshold and a longer second off-threshold to make it easier to turn on the output of the microphone 30, and a second threshold combination having a higher first off-threshold and a shorter second off-threshold to make it more difficult to turn on the output of the microphone 30, and turns on / off the voice output of the microphone 30 using either the first threshold combination or the second threshold combination according to the operation of the switch 35.

[0034] As shown in FIG. 11, when the main body 12 and the amplifier device 50 are separated, as shown in FIG. 37, the amplifier device 50 may be provided with a common voice switch 54 and a switch 55. The voice switch 54 receives the voice input transmitted from the main body 12a and the voice input transmitted from the main body 12b, and controls the voice output to the main body 12b and the voice output to the main body 12a. The voice switch 54 may be constituted by a DSP (Digital Signal Processor) as a signal processing circuit. The voice switch 54 monitors the voice level of the voice received from the main body 12a (the voice input from the microphone 20) via the voice transmission medium 40, compares it with a threshold value (the first on-threshold value), and when a voice having a voice level equal to or higher than the first on-threshold value is input, turns on the voice output from the main body 12a and transmits this voice to the main body 12b via the voice transmission medium 40. Similarly, the voice switch 54 monitors the voice level of the voice received from the main body 12b (the voice input from the microphone 30) via the voice transmission medium 40, compares it with a threshold value (the first on-threshold value), and when a voice having a voice level equal to or higher than the first on-threshold value is input, turns on the voice output from the main body 12b and transmits this voice to the main body 12a via the voice transmission medium 40. After once turning on the output from the main body 12a, the voice switch 54 continues to monitor the voice level of the voice received from the main body 12a, compares it with a threshold value (the first off-threshold value), and when the voice level of the voice input for a predetermined time (the second off-threshold value) or longer is equal to or lower than the first off-threshold value (that is, when a substantially silent state continues for a predetermined time or longer), turns off the output from the main body 12a. Similarly, after once turning on the output from the main body 12b, the voice switch 54 continues to monitor the voice level of the voice received from the main body 12b, compares it with a threshold value (the first off-threshold value), and when the voice level of the voice input for a predetermined time (the second off-threshold value) or longer is equal to or lower than the first off-threshold value (that is, when a substantially silent state continues for a predetermined time or longer), turns off the output from the main body 12b. Although the voice reception from the main body 12a and the voice reception from the main body 12b may conflict with each other, it is preferable to give priority to the one that started voice reception first.That is, while the voice output of the main body 12a is previously turned on, even if the voice level of the input voice of the main body 12b exceeds the first on-threshold value, the voice output of the main body 12b does not have to be turned on. The same applies conversely.

[0035] The switch 55 is a changing means for changing the operation parameters (the first on-threshold value, the first off-threshold value, the second off-threshold value) of the voice switch 54. The switch 55 is a manual switch such as a dip switch and is operated by the user of the communication system 10. The switch 55 is connected to the voice switch 54, and the voice switch 54 changes the operation parameters according to the operation of the switch 55. For example, the voice switch 54 holds a plurality of combinations of the first on-threshold value, the first off-threshold value, and the second off-threshold value, and turns on / off the voice output of the main bodies 12a and 12b using the combination selected according to the operation of the switch 55. For example, the voice switch 54 holds a first threshold combination having a lower first on-threshold value and a longer second off-threshold value so that the voice output is more easily turned on, and a second threshold combination having a higher first off-threshold value and a shorter second off-threshold value so that the voice output is more difficult to turn on, and turns on / off the voice output of the main bodies 12a and 12b using either the first threshold combination or the second threshold combination according to the operation of the switch 55.

[0036] The operation parameters of the voice switch 54 (first on-threshold, first off-threshold, second off-threshold) may hold different parameters for the main body 12a and the main body 12b. For example, the voice switch 54 holds a combination of a first on-threshold, a first off-threshold, and a second off-threshold (parameters for the main body 12a) for turning on / off the voice output of the main body 12a in response to the input voice from the main body 12a, and a combination of a first on-threshold, a first off-threshold, and a second off-threshold (parameters for the main body 12b) for turning on / off the voice output of the main body 12b in response to the input voice from the main body 12b, and turns on / off the voice output of the main body 12a using the parameters for the main body 12a and turns on / off the voice output of the main body 12b using the parameters for the main body 12b. For example, the parameters for the main body 12a suitable for the main body 12a provided on the responder 3 side may have a lower first on-threshold and a longer second off-threshold so that the voice output is more easily turned on, and the parameters for the main body 12b suitable for the main body 12b provided on the visitor 4 side may have a higher first on-threshold and a shorter second off-threshold so that the voice output is more difficult to turn on.

[0037] In the communication system 10, one of the main bodies 12 may be a wearable communication terminal that is not attached to the shielding material 2 but is worn by the user, instead of a speakerphone in which a microphone 20(30) and a speaker 21(31) are housed in one casing and attached to the shielding material 2. An example of the wearable communication terminal is a headset. A headset is a communication device equipped with a microphone and a speaker, worn on the user's head, and can be used instead of a speakerphone. For example, in an environment where a visitor 3 and a responder 4 have a conversation, such as in a movie theater or ticket counter in an amusement park, at a government office or train station window, or at a bank counter, the visitor 3 uses the speakerphone 12 attached to the shielding material 2, and it is assumed that the responder 4 wears and uses a pre-provided headset 12. By using a headset on the responder 4 side, the responder can respond without being particularly concerned about ambient noise. FIG. 38 is a diagram showing an example of the headset 12. The headset 12 shown in FIG. 38(a) includes a headband 80, a headphone unit 21(31) corresponding to the speaker 21(31), a microphone 20(30), and an arm 81. The headband 80 is worn across from one ear to the other ear on the user's head. Headphone units 21(31) are provided at both ends of the headband 80, and when the headband 80 is worn, the pair of headphone units 21(31) are positioned near the user's both ears. One end of the arm 81 is connected to one of the headphone units 21(31), and the other end is connected to the microphone 20(30). The arm 81 is adjusted so that the sound collection part of the microphone 20(30) is positioned near the user's mouth when the headband 80 is worn. The headset shown in FIG. 38(b) includes an ear hook part 82, an earphone unit 21(31) corresponding to the speaker 21(31), and a microphone 20(30). The ear hook part 82 is worn on one ear on the user's head. An earphone unit 21(31) is connected to one end of the ear hook part 82, and a microphone 20(30) is connected to the earphone unit 21(31). The earphone unit 21(31) is positioned near one ear of the user when the ear hook part 82 is placed on the ear, and the sound emitting part is inserted into the ear hole.The microphone 20(30) extends from the earphone part 21(31) onto the arm, and is adjusted so that the sound collection part of the microphone 20(30) is positioned at the mouth when the ear hook part 82 is placed on the ear.

[0038] In the communication system 10, one of the main bodies 12 may be configured to be able to arbitrarily select between a speakerphone in which a microphone 20(30) and a speaker 21(31) are housed in one housing and attached to the shielding material 2, and a wearable communication terminal that is not attached to the shielding material 2 but is worn by the user. As an example, FIG. 39 shows an example of the communication system 10 in which the main body 12b can arbitrarily select between a speakerphone and a wearable communication terminal. In the example shown in FIG. 39, in the communication system 10, as shown in FIG. 11, the main body 12 and the amplifier device 50 are separate bodies. The main body 12a is a speakerphone attached to the shielding material 2. On the other hand, the main body 12b includes a speakerphone-type main body 12bs attached to the shielding material 2 and a wearable communication terminal-type main body 12bw. The user can arbitrarily select between the main body 12bs and the main body 12bw. That is, depending on the user's intention, either the main body 12bs or the main body 12bw is connected to the amplifier device 50. Both the main bodies 12bs and 12bw are connected to the amplifier device 50 via the audio transmission medium 40 and the power transmission medium 41. The amplifier device 50 includes an equalizer 56 and a switch 57. The equalizer 56 is a frequency characteristic means for adjusting the frequency characteristics of the audio received from the main body 12a and output to the main body 12b, and the audio received from the main body 12b and output to the main body 12a. The equalizer 56 is preferably configured by a DSP as a signal processing circuit. When adjusting the frequency characteristics, the equalizer 56 holds, as adjustment parameters, the frequency band for adjustment, the level to be adjusted, etc. For example, the equalizer 56 performs a frequency characteristic adjustment process of raising the audio level in the high frequency range above the first frequency (for example, 800 Hz) by the first level (for example, 10 dB), and holds the combination of the first frequency and the first level as an adjustment parameter. Also, the equalizer 56 may hold a plurality of adjustment parameters that can be selectively used according to conditions. That is, different combinations of the first frequency and the first level are held as a plurality of adjustment parameters.As an example, the equalizer 56 holds a first adjustment parameter used when adjusting the frequency characteristics of the audio received from the main body 12a and output to the main body 12b, and a second adjustment parameter used when adjusting the frequency characteristics of the audio received from the main body 12b and output to the main body 12a. As an example, the equalizer 56 holds an adjustment parameter for a speakerphone suitable for adjusting the frequency characteristics of the audio received from the speakerphone main body 12bs and output to the main body 12a, and an adjustment parameter for a wearable communication terminal suitable for adjusting the frequency characteristics of the audio received from the wearable communication terminal main body 12bw and output to the main body 12a.

[0039] FIG. 40 shows, as an example, a case where the audio transmission medium 40 and the power transmission medium 41 between the main body 12 and the amplifier device 50 are physical cables. The main body 12 includes a cable C as the audio transmission medium 40 and the power transmission medium 41. The amplifier device 50 includes a terminal T1 to which the cable C of the main body 12a is connected, and a terminal T2 to which the cable C of the main body 12b (main body 12bs or main body 12bw) is connected. The user of the call system 10 can properly use the main body 12bs and the main body 12bw by connecting either cable of the main body 12bs and the main body 12bw to the terminal T2.

[0040] The equalizer 56 switches the adjustment parameter to be used from among a plurality of adjustment parameters according to a predetermined condition. As an example, the equalizer 56 switches the adjustment parameter according to the operation of the switch 57. The switch 57 is a changing means for manually changing the adjustment parameter of the equalizer 56. The switch 57 is a manual switch such as a DIP switch and is operated by a user of the call system 10. The switch 57 is connected to the equalizer 56, and the equalizer 56 changes the adjustment parameter according to the operation of the switch 57. As an example, the equalizer 56 detects which of the main body 12bs and the main body 12bw is connected, selects the adjustment parameter for the speakerphone when it detects that the main body 12bs is connected, and selects the adjustment parameter for the wearable call terminal when it detects that the main body 12bw is connected. When the main body 12b and the amplifier device 50 are connected via the cable C as shown in FIG. 40, it is preferable to determine which of the main body 12bs and the main body 12bw is connected to the terminal T2 of the amplifier device 50 and switch the adjustment parameter according to the determination result. For example, using the difference between the impedance of the main body 12bs and the impedance of the main body 12bw, the amplifier device 50 is provided with measuring means for measuring the impedance of the main body 12b connected to the terminal T2, and when an impedance equal to or higher than a predetermined threshold value is measured, it is determined that the main body 12bw is connected, and when an impedance lower than the predetermined threshold value is measured, it is determined that the main body 12bs is connected.

[0041] Also, the amplifier device 50 may include the voice switch 54 described above, and hold, as operation parameters (first on threshold, first off threshold, second off threshold), operation parameters for a speakerphone suitable for turning on / off the output of the voice received from the main body 12bs which is a speakerphone, and operation parameters for a wearable communication terminal suitable for turning on / off the output of the voice received from the main body 12bw which is a wearable communication terminal. The amplifier device 50 may include the switch 55 described above, and select and use either the operation parameters for a speakerphone or the operation parameters for a wearable communication terminal according to the operation of the switch 55. Alternatively, the voice switch 54 may detect whether either the main body 12bs or the main body 12bw is connected as described above, select the operation parameters for a speakerphone when detecting that the main body 12bs is connected, and select the operation parameters for a wearable communication terminal when detecting that the main body 12bw is connected.

[0042] Furthermore, the amplifier device 50 may hold a combination of operation parameters for the voice switch 54 and adjustment parameters for the equalizer 56. In this case, for example, a combination (first combination) of the operation parameters for the speakerphone of the voice switch 54 and the adjustment parameters for the speakerphone of the equalizer 56 is held, and a combination (second combination) of the operation parameters for the wearable communication terminal of the voice switch 54 and the adjustment parameters for the wearable terminal of the equalizer 56 is held. In this case, the switch 55 and the switch 57 are integrated, and the amplifier device 50 selects and uses the first combination or the second combination according to the switch operation. When the first combination is selected, the voice switch 54 turns on / off the output of the voice received from the main body 12b using the operation parameters for the speakerphone, and the equalizer 56 adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the speakerphone. When the second combination is selected, the voice switch 54 turns on / off the output of the voice received from the main body 12b using the operation parameters for the wearable communication terminal, and the equalizer 56 adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the wearable communication terminal. Alternatively, the amplifier device 50 may detect whether either the main body 12bs or the main body 12bw is connected as described above, select the first combination when it detects that the main body 12bs is connected, and select the second combination when it detects that the main body 12bw is connected.

[0043] Furthermore, as operation parameters of the voice switch 54 that turns on / off the output of the voice received from the main body 12a, speakerphone operation parameters suitable when the other party is the main body 12bs which is a speakerphone, and wearable communication terminal operation parameters suitable when the other party is the main body 12bw which is a wearable communication terminal may be held. The voice switch 54 selects and uses the speakerphone operation parameters or the wearable communication terminal operation parameters according to the operation by the switch 55 as described above, or according to the detection of which of the main body 12bs and the main body 12bw is connected, and turns on / off the output of the voice received from the main body 12a. Similarly, as adjustment parameters of the equalizer 56 that adjusts the frequency characteristics of the voice received from the main body 12a, speakerphone adjustment parameters suitable when the other party is the main body 12bs which is a speakerphone, and wearable communication terminal adjustment parameters suitable when the other party is the main body 12bw which is a wearable communication terminal may be held. The equalizer 56 selects and uses the speakerphone adjustment parameters or the wearable communication terminal adjustment parameters according to the operation by the switch 57 as described above, or according to the detection of which of the main body 12bs and the main body 12bw is connected, and adjusts the frequency characteristics of the voice received from the main body 12a.

[0044] Furthermore, in the voice switch 54, the operation parameters for the speakerphone and the operation parameters for the speakerphone are preferably held in combination, and the operation parameters for the wearable communication terminal and the operation parameters for the wearable communication terminal are preferably held in combination. Thereby, as described above, according to the operation by the switch 55 or according to the detection of which of the main body 12bs and the main body 12bw is connected, the voice switch 54 turns on / off the output of the voice received from the main body 12b using the operation parameters for the speakerphone and turns on / off the output of the voice received from the main body 12a using the operation parameters for the speakerphone, or turns on / off the output of the voice received from the main body 12b using the operation parameters for the wearable communication terminal and turns on / off the output of the voice received from the main body 12a using the operation parameters for the wearable communication terminal. Similarly, in the equalizer 56, the adjustment parameters for the speakerphone and the adjustment parameters for the speakerphone are preferably held in combination, and the adjustment parameters for the wearable communication terminal and the operation parameters for the wearable communication terminal are preferably held in combination. Thereby, as described above, according to the operation by the switch 57 or according to the detection of which of the main body 12bs and the main body 12bw is connected, the equalizer 56 adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the speakerphone and adjusts the frequency characteristics of the voice received from the main body 12a using the adjustment parameters for the speakerphone, or adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the wearable communication terminal and adjusts the frequency characteristics of the voice received from the main body 12a using the adjustment parameters for the wearable communication terminal.

[0045] Furthermore, the operation parameters for the loudspeaker phone and the operation parameters for the loudspeaker phone in the voice switch 54, and the adjustment parameters for the loudspeaker phone and the adjustment parameters for the loudspeaker phone in the equalizer 56 are held in combination as a unit (loudspeaker phone parameter combination), and the operation parameters for the wearable communication terminal and the operation parameters for the wearable communication terminal in the voice switch 54, and the adjustment parameters for the wearable communication terminal and the adjustment parameters for the wearable communication terminal in the equalizer 56 are preferably held in combination as a unit (wearable communication terminal parameter combination). As described above, according to the switch operation or according to the detection of which of the main body 12bs and the main body 12bw is connected, the loudspeaker phone parameter combination or the wearable communication terminal parameter combination is selected. When the loudspeaker phone parameter combination is selected, the voice switch 54 turns on / off the output of the voice received from the main body 12b using the operation parameters for the loudspeaker phone and turns on / off the output of the voice received from the main body 12a using the operation parameters for the loudspeaker phone, and the equalizer 56 adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the loudspeaker phone and adjusts the frequency characteristics of the voice received from the main body 12a using the adjustment parameters for the loudspeaker phone. On the other hand, when the wearable communication terminal parameter combination is selected, the voice switch 54 turns on / off the output of the voice received from the main body 12b using the operation parameters for the wearable communication terminal and turns on / off the output of the voice received from the main body 12a using the operation parameters for the wearable communication terminal, and the equalizer 56 adjusts the frequency characteristics of the voice received from the main body 12b using the adjustment parameters for the wearable communication terminal and adjusts the frequency characteristics of the voice received from the main body 12a using the adjustment parameters for the wearable communication terminal.

[0046] FIG. 41 shows, as another example, in the communication system 10 where the main bodies 12a and 12b directly amplify and transmit voices to each other as shown in FIGS. 13 to 14, an example where the main body 12b can arbitrarily select between a speakerphone and a wearable communication terminal. The main body 12a is a speakerphone attached to the shielding material 2. On the other hand, the main body 12b includes a speakerphone-type main body 12bs attached to the shielding material 2 and a wearable communication terminal-type main body 12bw. The user can arbitrarily select between the main body 12bs and the main body 12bw. That is, depending on the user's intention, either the main body 12bs or the main body 12bw is connected to the main body 12a. Both the main bodies 12bs and 12bw are connected to the main body 12a via the voice transmission medium 40 and the power transmission medium 41. The main body 12a includes a voice switch 24, a switch 25, an equalizer 26, and a switch 27. The schematic configuration and functions of the voice switch 24 and the switch 25 are as described above. The voice switch 24 may hold a plurality of operation parameters (first on-threshold, second threshold, first off-threshold, second off-threshold) that can be selectively used according to conditions. As an example, when the connected main body 12b is the main body 12bs which is a speakerphone, the voice switch 24 holds operation parameters for a speakerphone suitable for turning on / off the output of the input voice of the microphone 20, and when the connected main body 12b is the main body 12bw which is a wearable communication terminal, it holds operation parameters for a wearable communication terminal suitable for turning on / off the output of the input voice of the microphone 20. The equalizer 26 is a frequency characteristic means for adjusting the frequency characteristics of the voice output from the main body 12a to the main body 12b. The equalizer 26 may be configured by a DSP as a signal processing circuit. When adjusting the frequency characteristics, the equalizer 26 holds, as adjustment parameters, the frequency band for adjustment, the level to be adjusted, etc. For example, the equalizer 26 performs a frequency characteristic adjustment process of raising the voice level in the high frequency range above the first frequency (for example, 800 Hz) by the first level (for example, 10 dB), and holds the combination of this first frequency and the first level as an adjustment parameter. Also, the equalizer 26 may hold a plurality of adjustment parameters that can be selectively used according to conditions.That is, combinations of different first frequencies and first levels are held as a plurality of adjustment parameters. As an example, when the connected main body 12b is the main body 12bs which is a horn speaker, the equalizer 26 holds adjustment parameters suitable for a horn speaker, and when the connected main body 12b is the main body 12bw which is a wearable communication terminal, it holds adjustment parameters suitable for a wearable communication terminal.

[0047] FIG. 42 shows, as an example, a case where the voice transmission medium 40 and the power transmission medium 41 between the main body 12a and the main body 12b are physical cables. The main body 12b (main body 12bs and main body 12bw) includes a cable C as the voice transmission medium 40 and the power transmission medium 41. The main body 12a includes a terminal T for connecting the cable C of the main body 12b. A user of the call system 10 can properly use the main body 12bs and the main body 12bw by connecting either the cable of the main body 12bs or the main body 12bw to the terminal T.

[0048] The voice switch 24 switches the operation parameter to be used from among a plurality of operation parameters according to a predetermined condition, in the same manner as the operation of the voice switch 54 described above. As an example, the voice switch 24 selects and uses the operation parameter for a horn speaker or the operation parameter for a wearable communication terminal according to the operation by the switch 25 or according to the detection of which of the main body 12bs and the main body 12bw is connected, and turns on / off the output of the input voice of the microphone 20. When the main body 12b and the main body 12a are connected via the cable C as shown in FIG. 42, the main body 12a may determine which of the main body 12bs and the main body 12bw is connected to the terminal T, and switch the operation parameter according to the determination result. That is, for example, by utilizing the difference between the impedance of the main body 12bs and the impedance of the main body 12bw, the main body 12a includes measuring means for measuring the impedance of the main body 12b connected to the terminal T, and determines that the main body 12bw is connected when an impedance equal to or higher than a predetermined threshold value is measured, and determines that the main body 12bs is connected when an impedance lower than the predetermined threshold value is measured.

[0049] The equalizer 26 switches the adjustment parameter to be used from among a plurality of adjustment parameters according to a predetermined condition. As an example, the equalizer 26 switches the adjustment parameter according to the operation of the switch 27. The switch 27 is a changing means for manually changing the adjustment parameter of the equalizer 26. The switch 27 is a manual switch such as a DIP switch and is operated by a user of the communication system 10. The switch 27 is connected to the equalizer 26, and the equalizer 26 changes the adjustment parameter according to the operation of the switch 27 (for example, selects and uses the adjustment parameter for the speakerphone or the adjustment parameter for the wearable communication terminal according to the operation of the switch 27). As an example, the equalizer 26 detects which of the main body 12bs and the main body 12bw is connected to the main body 12a, and when it detects that the main body 12bs is connected, it selects the adjustment parameter for the speakerphone, and when it detects that the main body 12bw is connected, it selects the adjustment parameter for the wearable communication terminal. When the main body 12b and the main body 12a are connected via the cable C as shown in FIG. 42, it is preferable to determine which of the main body 12bs and the main body 12bw is connected to the terminal T of the main body 12a and switch the adjustment parameter according to the determination result. For example, utilizing the difference between the impedance of the main body 12bs and the impedance of the main body 12bw, the main body 12a is provided with measuring means for measuring the impedance of the main body 12b connected to the terminal T, and when an impedance equal to or higher than a predetermined threshold value is measured, it is determined that the main body 12bw is connected, and when an impedance lower than the predetermined threshold value is measured, it is determined that the main body 12bs is connected.

[0050] In addition, the speakerphone operation parameters in the voice switch 24 and the speakerphone adjustment parameters in the equalizer 6 may be held in combination as a unit (speakerphone combination), and the wearable call terminal operation parameters in the voice switch 24 and the wearable call terminal adjustment parameters in the equalizer 26 may be held in combination as a unit (wearable call terminal combination). As described above, according to the switch operation or according to the detection of which of the main bodies 12bs and 12bw is connected to the main body 12a, the speakerphone combination or the wearable call terminal combination is selected. When the speakerphone combination is selected, the voice switch 24 turns on / off the output of the input voice of the microphone 20 using the speakerphone operation parameters, and the equalizer 26 adjusts the frequency characteristics of the input voice of the microphone 20 using the speakerphone adjustment parameters. On the other hand, when the wearable call terminal combination is selected, the voice switch 24 turns on / off the output of the input voice of the microphone 20 using the wearable call terminal operation parameters, and the equalizer 26 adjusts the frequency characteristics of the input voice of the microphone 20 using the wearable call terminal adjustment parameters.

[0051] In the call system 10, it is also possible to perform not only one-on-one calls but also one-to-many or many-to-many calls using a plurality of main bodies 12. That is, it is preferable to connect one or more main bodies 12a and one or more main bodies 12b so that calls can be made. As an example, a splitter for distributing audio signals may be used to enable one-to-many or many-to-many calls. FIG. 43 is a diagram showing an example of the splitter 75. The splitter 75 is a signal distributor that includes a plurality of terminals for signal input / output and outputs the signal input from one terminal from all the other terminals. In the example shown in FIG. 43, the splitter 75 includes three terminals (terminals T11 to T13).

[0052] FIG. 44 shows an example of using a splitter 75 in a configuration where the main body 12 and the amplifier device 50 are separate as shown in FIGS. 11 to 12. In the example shown in FIG. 44, two splitters 75 (75-1, 75-2) are used. The terminal T1 of the amplifier device 50 is connected to the terminal T11 of the splitter 75-1, the terminal T12 of the splitter 75-1 is connected to the first main body 12a (main body 12a-1), and the terminal T13 of the splitter 75-1 is connected to the second main body 12a (main body 12a-2). Through the splitter 75-1, an audio transmission medium 40 and a power transmission medium 41 are formed between the amplifier device 50 and the main body 12a-1, and through the splitter 75-1, an audio transmission medium 40 and a power transmission medium 41 are formed between the amplifier device 50 and the main body 12a-2. Also, the terminal T2 of the amplifier device 50 is connected to the terminal T11 of the splitter 75-2, the terminal T12 of the splitter 75-2 is connected to the first main body 12b (main body 12b-1), and the terminal T13 of the splitter 75-2 is connected to the second main body 12b (main body 12b-2). Through the splitter 75-2, an audio transmission medium 40 and a power transmission medium 41 are formed between the amplifier device 50 and the main body 12b-1, and through the splitter 75-2, an audio transmission medium 40 and a power transmission medium 41 are formed between the amplifier device 50 and the main body 12b-2. With this configuration, multi-party calls can be made between two main bodies 12a and two main bodies 12b. Also, by connecting one terminal of one splitter 75 to one terminal of another splitter 75 in a daisy chain, multi-party calls can be made between more main bodies 12.

[0053] FIG. 45 shows an example of using a splitter 75 in a configuration where the main bodies 12 are directly connected as shown in FIGS. 13 to 14. The terminal T of the main body 12a is connected to the terminal T11 of the splitter 75, the terminal T12 of the splitter 75 is connected to the first main body 12b (main body 12b-1), and the terminal T13 of the splitter 75 is connected to the second main body 12b (main body 12b-2). Through the splitter 75, an audio transmission medium 40 and a power transmission medium 41 are formed between the main body 12a and the main body 12b-1, and an audio transmission medium 40 and a power transmission medium 41 are formed between the main body 12a and the main body 12b-2 through the splitter 75. With this configuration, a one-to-many call can be made between the main body 12a and two main bodies 12b. Also, by connecting one terminal of one splitter 75 to one terminal of another splitter 75 in a daisy chain, a one-to-many call can be made between the main body 12a and more main bodies 12b.

[0054] In addition to the above-described configuration, various changes can be made to the configuration of the call system 10. In the above-described example, an example in which the magnet 15 or the metal part 16 is provided to directly self-support and fix the main body 12 to the shielding material 2, or an example in which the extension part 65 and the receiving part 66 are provided to directly self-support and fix the main body 12 to the shielding material 2 have been described, but the present invention is not limited thereto, and other means may be used. For example, a double-sided tape may be provided on the back surface of the main body 12 to directly attach the back surface of the main body 12 to the shielding material 2.

[0055] In this way, by using the splitter 75, the call system 10 can be applied not only to one-to-one calls between the responder 4 and the visitor 3 in places such as amusement parks, ticket sales counters in movie theaters, windows in government offices and stations, and bank counters, but also to one-to-many calls and multi-to-many calls with the shielding material 2 interposed therebetween in situations such as meetings or group interviews with three or more people.

[0056] In addition to the above-described configuration, various modifications can be made to the configuration of the communication system 10. For example, in the examples shown in FIGS. 3 to 6, the support portion 11 is provided on the back surface of the main body 12, but the support portion 11 may be provided on the upper surface or side surface of the main body 12 that is substantially orthogonal to the directions D1 and D2.

Description of Reference Numerals

[0057] 1 Space 2 Shield 3 Respondent (Speaker) 4 Visitor (Speaker) 7 Hole 10 Communication System 11 Support Portion 12 Main Body (Speakerphone) 15 Magnet 16 Metal Portion 17 Accessory 20 Microphone 21 Speaker 22 Amplifier 23 Power Supply 24 Voice Switch 25 Switch 26 Equalizer 27 Switch 30 Microphone 31 Speaker 32 Amplifier 33 Power Supply 40 Voice Transmission Medium 41 Power Transmission Medium 50 Amplifier Device 51 Amplifier 52 Power Supply 54 Voice Switch 55 Switch 56 Equalizer 57 Switch 60 Vibration Absorber or Anti-Vibration Material 65 Extension Portion 66 Receiving Portion 68 Plug 69 Jack 70 Accessory 71 Receiving Portion

Claims

1. A call system for assisting conversation between two parties facing each other through a shielding material, comprising: A pair of call units including a first call unit that can be attached to the shielding material by sandwiching the shielding material and a second call unit that can be attached to the shielding material by sandwiching the shielding material; The first call unit includes a first microphone and a first speaker; The second call unit includes a second microphone and a second speaker; It is configured to amplify the sound input from the first microphone and output it from the second speaker, and amplify the sound input from the second microphone and output it from the first speaker; The shielding material has at least one hole penetrating both sides facing each of the two parties; It is configured to independently fix the first call unit and the second call unit to the shielding material through the hole; A first mounting means having an extension portion extending from a surface (first back surface) of the first housing of the first call unit, which is substantially opposite to the sound collection direction of the first microphone and the sound emission direction of the first speaker; A second mounting means provided on a surface (second back surface) of the second housing of the second call unit, which is substantially opposite to the sound collection direction of the second microphone and the sound emission direction of the second speaker, and having a receiving portion that can be fitted into the extension portion; Through the hole of the shielding material, the receiving portion fits into the extension portion, so that the first call unit and the second call unit are attached to the shielding material; The extension portion includes a male plug, the receiving portion includes a female jack, and the call system in which the receiving portion fits into the extension portion due to the fitting of the plug and the jack.

2. The call system according to claim 1, wherein: An absorbent material or a vibration-proof material is provided at a position on the first back surface of the first call unit that abuts against the shielding material when the first call unit and the second call unit are attached to the shielding material; The call unit in which an absorbent material or a vibration-proof material is provided at a position on the second back surface of the second call unit that abuts against the shielding material when the first call unit and the second call unit are attached to the shielding material.

3. The call system according to claim 1, wherein: A call system configured such that the voice input by the first microphone is output from the second speaker while the voice input by the second microphone is output from the first speaker via the plug and the jack.

4. The call system according to claim 1, wherein the first call unit includes a power supply, and the second call unit does not have a power supply, a call system configured to supply power from the power supply of the first call unit to the second call unit via the plug and the jack.

Images