JP5213584B2 - Call system - Google Patents

Description

  The present invention relates to a call system, and more particularly to a call system that enables a mutual call in a high noise environment.

Conventionally, as a device for realizing a group call in a high noise environment such as a factory, a method using a bone conduction type earphone microphone, a method using a directional microphone, or a speaker that reverses the phase of a noise sound is used. Methods are known.
In the case of the bone conduction type earphone microphone, the sound that passes through the human skull, muscles and skin and reaches the earphone microphone is used. Therefore, in order to suppress the noise from entering, the noise should not enter the sound path. It is necessary to. However, sound that propagates in the air is input through the earphone housing, etc., even if there is no such thing as an air diaphragm, and is also input through the human skull, muscles, and skin, resulting in noise. End up.

In addition, the frequency characteristics of sound propagation, such as the skull, are biased toward low frequencies, making it muffled and difficult to hear, and the earphone microphone must be pressed to the skull to some extent, so it feels good to wear Absent.
In the case of a method using a directional microphone, a microphone having a high directivity is arranged near the mouth toward the mouth, and another omnidirectional microphone is arranged to pick up surrounding sounds. The call volume is obtained by electrically subtracting the output of the omnidirectional microphone from the output of the directional microphone, so that the sound becomes relatively loud if the output of the omnidirectional microphone is small, but it is effective if the noise is loud Is small. In addition, when the noise source is in the same direction as the mouth, the effect is small, and the microphone has to be placed in front of the mouth, which is obstructive during work.

  The noise phase inversion method captures external noise with a microphone placed close to the ear, electrically generates a sound of the same magnitude and frequency, but opposite in phase, and air-flows toward the ear with an earphone. Noise is canceled out by radiating in. In the case of this method, it is difficult to make a sound that is completely the same size and frequency and opposite in phase because it is difficult to obtain the overall linearity of the microphone, electric circuit, and earphone, and the frequency characteristics are not flat, etc. The effect is small when the noise is loud. Moreover, it cannot cope with the microphone picking up noise.

As the above-described bone conduction type earphone microphone, for example, there is a “bone conduction earphone microphone” (see Patent Document 1).
JP-A-8-195994

  As described above, for example, even in a high noise environment exceeding 85 to 90 dB, for example, a versatile and practical call system capable of making a voice call and intercommunication and confirmation without being disturbed by noise. Did not exist.

Furthermore, when the telephone system is actually used in a high noise environment, it is necessary to cope with the following situation.
When making a group call with a large number of people, if one of the callers is in a noisy environment, noise will be transmitted from the caller's microphone to the other caller's earphones, making the group call impossible. . In such a situation, any sound that is not related to conversation or signal sound through the call system is regarded as noise. Sound generated when the machine is operated on site, material contact, breakage, and sound generated during processing The voice of a person unrelated to the call system becomes noise.

In addition, when the call system has a broadcast or paging call function using a mobile terminal, howling occurs with the loudspeaker depending on the position of the mobile terminal.
In addition, when trying to perform group calls and broadcasts simultaneously using multiple mobile voice radio devices, even if the communication method is the same standard, various manufacturers and models have different design details. The problem is that the devices are mixed and used, and the consistent level from the speaker's microphone to the listener's earphone or microphone cannot be secured, resulting in a difference in volume or poor sound quality. There was a point.

In a conventional call system, the devices to be used are limited to a compatible range, that is, only a specific model of a specific manufacturer can be used in a certain call system, and an earphone having a predetermined characteristic is used. Because only the microphone and the microphone could be used, the above problem did not occur.
The object of the present invention is to enable mutual communication and confirmation by voice call without being disturbed by noise even in a high noise environment, and even when a plurality of portable voice radio devices of different manufacturers and models are used simultaneously. It is to provide a versatile and practical call system that can ensure a good call state.

In order to achieve the above object, a call system according to the present invention includes a server that performs communication control and individual terminal control, a switching hub that configures a wired LAN and an access point that configures a wireless LAN connected to the server, Fixed telephone and loudspeaker broadcasting terminal connected to the switching hub, a portable voice radio device connected to the access point, and an ear hole insertion connected to the portable voice radio device to prevent noise from entering. form, has a single diaphragm for converting and vice versa from the electric signal to air vibration, microphone earphone conducted electrical isolation of the diaphragm drive circuit for howling prevention, and the Yes and Bozatsu headset corresponding to full-duplex communication having the noise processing apparatus for removing processing for noise had penetrated into the microphone earphone The server includes level adjustment means for adjusting a received voice signal that is different for each portable voice radio apparatus to a level that matches an optimum value for each portable voice radio apparatus to be connected in advance. Yes.

  Also, in the present invention, the server has a function of performing a group call and broadcasting, and the noise processing device detects and removes a signal other than the voice signal of the caller from an input signal from the microphone earphone. It is preferable to perform a group call under high noise and a transmission during broadcasting via the microphone earphone, having a noise processing circuit and affecting the transmitted voice as external noise.

According to the present invention, a switching hub that constitutes a wired LAN and an access point that constitutes a wireless LAN are connected to a server that performs communication control and individual terminal control, and the switching hub is used for fixed telephones and loudspeaker broadcasting. A terminal is connected, and a portable voice radio apparatus is connected to the access point. This portable voice radio apparatus is an ear hole insertion type that suppresses the entry of noise , and the conversion from electrical signal to air vibration and vice versa. A microphone earphone that has a diaphragm that performs conversion and electrically isolates the diaphragm drive circuit to prevent howling , and noise processing that removes noise that has entered the microphone earphone A level control hand equipped with a function for performing group calls and broadcasting is connected to a dustproof headset compatible with full-duplex communication. Accordingly, the mobile voice radio device different reception voice signal for each advance, and transmits the adjusted level was the optimum value of the mobile voice radio device each time it connects.

  For this reason, even in a noisy environment, it is possible to reliably communicate and confirm by voice calls without being disturbed by noise, and good calls even when using multiple mobile voice radio devices of different manufacturers and models at the same time It is possible to construct a versatile and practical call system that can ensure the state.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory diagram schematically showing the configuration of a call system according to an embodiment of the present invention. As shown in FIG. 1, a call system 10 includes a server 11, a switching hub (HUB) 12, a plurality (two in this example) of access points 13a and 13b, a fixed telephone 14, and a plurality (two in this example). ) Loudspeaker speakers 15a and 15b, a plurality (in this example, five) of portable voice radio apparatuses 16a to 16e, and a plurality (in this example, five) of anti-noise headsets 17a to 17a. 17e.
With this call system 10, a group call can be made among a plurality of users who wear the portable headsets 17a to 17e and carry the portable voice radio apparatuses 16a to 16e, respectively, to talk to each other.

  As the server 11, for example, a multi-function call control voice call server for group calls / broadcasts having a function to perform group calls and broadcasts is used. Control of line connection / disconnection between call terminals, that is, wireless LAN access It performs communication control such as control of an access point that connects a call terminal to a wireless LAN, such as a handover between points. It also controls conference calls with multiple call terminals. In the case of a conference call, the voices of the respective call terminals connected to a specific address (phone number) are added by the server 11 and distributed to the respective call terminals. A switching hub 12 is connected to the server 11. Furthermore, the server 11 performs processing for combining various general-purpose microphone characteristics under low noise.

The switching hub 12 physically connects the server 11 and a plurality of call terminals, and configures a wired LAN (Local Area Network) by connecting individual devices. Unlike a simple hub, the switching hub 12 reads a MAC (Media Access Control) address on each data frame, and flows information only to an appropriate wiring to which a transmission partner is connected among a plurality of wirings.
The switching hub 12 includes access points 13a and 13b constituting a wireless LAN, a fixed telephone 14 connected to a wired LAN and capable of talking, and a loudspeaker broadcasting terminal (Internet Protocol-Amplifier: IP-AMP) 18a. , 18b are connected to speakers 15a, 15b, which are connected to a wired LAN and emit a wide range of sounds on site.

The access points 13a and 13b are base stations for connecting wireless devices to the wired LAN, which function in the same manner as a switching hub in the wired LAN in the wireless LAN, and are IEEE. 802.11 is used.
The access point 13a includes, for example, a portable audio wireless device 16a, 16b such as a PDA (Personal Digital Assistant) via a wireless LAN, and the access point 13b includes, for example, a wireless IP phone via a wireless LAN. Portable audio wireless devices 16c, 16d, and 16e are connected to each other.

The PDA 16a, 16b is wirelessly connected with a dustproof wireless headset 17a, 17b, and the wireless IP phones 16c, 16d, 16e are wired with a dustproof wired headset 17c, 17d, 17e. These dust-proof headsets 17a to 17e are compatible with full duplex communication (full duplex).
The fixed telephone 14 is installed at a fixed position such as a driver's cab and connected to a wired LAN. For example, voice is compressed by various encoding methods and converted into packets, and then transmitted over the network in real time by IP to make a call. It is a telephone (IP phone).

The speakers 15a and 15b are used when performing broadcast or paging call in a wide premises, and directly convert the audio data converted into frame data on the wired LAN to output.
The portable audio wireless devices 16a and 16b are basically the same as fixed IP phones, but are connected to a wired LAN via a wireless LAN. Since it is a mobile device, the connected wireless LAN access point may change during a call or during a call. When changing the connected wireless LAN access point during a continuous call, control called handover is performed. Is called.

  FIG. 2 is an explanatory diagram schematically showing another configuration example of the call system of FIG. As shown in FIG. 2, portable voice radio devices 16f to 16h may be further connected to the call system 10 (see FIG. 1). The existing telephone exchange 20 connected to the server 11 via a VoIP-GW (Voice over Internet Protocol-Gateway) 19 has an existing local PHS (Personal Handyphone System) antenna 21, a public switched telephone network 22 a and a mobile telephone network. A mobile phone base station 23 is connected via 22b, and a public PHS antenna 24 is connected via public switched telephone network 22a and public PHS network 22c.

  The existing local PHS antenna 21 has an existing local PHS terminal (portable voice radio device) 16f connected to the anti-corrosion wired headset 17f via PHS radio, and the mobile phone base station 23 has a mobile radio. The mobile phone terminal (portable voice radio device) 16g to which the dustproof wired headset 17g is connected is connected to the public PHS antenna 24 via the public PHS radio and the public to which the dustproof wired headset 17h is connected. A PHS terminal (portable voice radio apparatus) 16h is wirelessly connected.

The dustproof wireless headsets 17a and 17b and the dustproof wired headsets 17c to 17h illustrated in FIG. 1 and FIG. 2 include an ear hole insertion type microphone earphone 25 and a noise processing device 26 that suppress noise from entering. Yes.
An ear hole insertion type microphone earphone 25 that suppresses the entry of noise converts electrical signals of received voices input from the portable voice radio apparatuses 16a to 16b into air vibrations, and converts transmitted voices into electrical signals. It has only one common diaphragm that simultaneously realizes output to the portable voice radio apparatuses 16a to 16b. The microphone earphone 25 is inserted into the ear hole of the caller so as to be in close contact with the inner wall surface of the ear hole so that the ear hole is hermetically sealed. It has a structure.

The noise processing device 26 has a noise processing circuit that detects and removes a signal other than the voice signal of the caller, that is, a signal that becomes noise, from an input signal from the microphone earphone 25. Further, the noise processing circuit performs a process of selectively amplifying the voice of the caller and suppressing the others.
By using the ear hole type microphone earphone 25 and the noise processing device 26 that suppress noise from entering, various voices in the vicinity such as human speech, machine operation sound, vehicle running sound, etc. are transmitted to the transmitted voice as external noise. Even in a noisy environment where a telephone call is difficult, it is possible to eliminate the influence of external noise as much as possible, and to eliminate the mixing of noise into the voice transmission path, the occurrence of howling, and the like.

As a result, it is possible to realize a group call by a plurality of callers in a high noise environment that could not be realized by the conventional call system, and smooth broadcast and paging without generating howling with the speakers 15a and 15b. Broadcast can be realized.
3A and 3B show a flow when a group call is performed. FIG. 3A is a sequence chart in the case of convocation, and FIG. 3B is a sequence chart in the case of participation. FIG. 4 is a sequence chart showing a flow when broadcasting is performed.

  As shown in FIG. 3A, when a group call is performed by invitation, first, the terminal 16a, which is the conference invitation source, sends terminals 16b, 16c, 16d to the server (multifunction call control voice call server) 11. (1) request to convene a meeting with Next, the server 11 requests connection to the terminal 16b (2), and further requests connection to the terminal 16c (3) and to the terminal 16d (4). In response to the request, the terminals 16b, 16c, and 16d sequentially respond (5), (6), and (7), thereby establishing the conference environment.

Next, when the conference is terminated by the terminal 16a serving as the conference caller disconnecting the line (8), the server 11 also disconnects the lines of the other terminals 16b, 16c, 16d (9), (10), (11). The withdrawal from the conference can also be performed by disconnecting the line by each terminal 16b, 16c, 16d that is the callee. However, you cannot reconnect from the called terminal.
As shown in FIG. 3B, when a group call is performed by participation, the terminals 16a, 16b, 16c, and 16d are connected to the server 11 by calling a special number dial set in advance (1), ( 2), (3), (4). In addition, withdrawal from the conference can be made arbitrarily by each participating terminal disconnecting the line (5), (6), (7), (8), and reconnection is also possible by calling a special number dial. Is possible.

  As shown in FIG. 4, when broadcasting is performed, first, a broadcast special number dial is transmitted from the terminal 16a to request the server 11 to broadcast (1). Next, the server 11 calls the IP-AMP 18 to make it receive (2). Next, a voice (digital) signal is transmitted from the terminal 16a via the server 11 (3) to the IP-AMP 18 (4). Upon receiving the audio (digital) signal, the IP-AMP 18 converts the audio (digital) signal from digital to analog, amplifies the converted analog signal, and transmits it to the speaker 15 to start broadcasting (5).

  In a group call, all voice signals input from a plurality of portable voice radio apparatuses 16 are collected in the server 11 (for group call), and a sum of the voice signals is created. On the contrary, the sum voice signal is sent from the server 11 to all portable voice radio apparatuses 16 participating in the group call through the wireless LAN. The received portable voice radio apparatus 16 restores the total voice signal from the digital code to an analog signal. As a result, any portable voice radio apparatus 16 can finally hear the voices input from all other portable voice radio apparatuses 16.

  However, in reality, not the audio signals input from all the portable audio radio apparatuses 16, but the audio signals sent by themselves are excluded and the other audio signals are summed and transmitted. For example, when the portable voice radio devices 16a to 16d are participating in a conference call, the portable voice radio device 16a has the sum of the transmission signals of the portable voice radio devices 16b to 16d except for the signal transmitted by itself. Sent back. Similarly, the sum of the transmission signals of the portable voice radio apparatuses 16a, 16c, and 16d is sent back to the portable voice radio apparatus 16b. Hereinafter, the same processing is performed, but the description is omitted.

  In the call system 10 of the present invention, as already described, the noise suppression type microphone earphone 25 is used instead of the earphone or the speaker that is the original output device of the portable audio wireless device 16. However, since the drive voltage applied from the output circuit to the earphone or the speaker that is the original output device of the portable audio wireless device 16 is not standardized and varies according to the manufacturer's design, the portable audio wireless device is not changed as it is. This is inconvenient because there are a plurality of drive voltages whose output levels to the noise suppression type microphone earphone 25 serving as the input / output device of the device 16 are different for each portable voice radio device 16.

For example, if the voltage output to the noise suppression type microphone earphone 25 exceeds the appropriate range and is too large, distortion occurs in the input circuit of the noise suppression type microphone earphone 25, resulting in deterioration of sound quality. The incoming voice becomes difficult to hear.
Therefore, in the present invention, the server 11 that suppresses the group call includes a level adjustment unit that adjusts the received voice signal level to an appropriate range for each model of the portable voice radio apparatus 16 connected in advance. By this level adjustment means, a received voice signal that differs for each portable voice radio apparatus 16 is adjusted in advance to a level that matches the optimum value for each portable voice radio apparatus 16 to be connected.

  The embodiment will be described. The following information processing such as data storage / calculation is performed in the server 11 by cooperation of an application (software) and hardware resources. The maximum value of the output voltage applied from the output circuit to the earphone or speaker of the portable voice radio apparatus 16 is measured for each model of the portable voice radio apparatus 16, and the values Vta, Vtb,. The maximum output voltages Vta, Vtb,... Of the received voices of the portable voice radio apparatuses 16a to 16d that may be used for the group call in the call system 10 are recorded in advance in the storage device of the server 11. On the other hand, an appropriate maximum input voltage that does not cause distortion in the noise suppression type microphone earphone 25 is Vs. This value is also recorded in advance in the storage device of the server 11.

As shown in FIG. 3A, when the mobile voice wireless device 16 participates in the group call and starts the group call, the server 11 calls the mobile voice wireless device 16a that invited the group call and the mobile voice that was called. Know that it is a wireless device 16b-16d. Then, the server 11 causes the maximum values Vta to Vtd of the output voltage corresponding to the mobile audio wireless devices 16a to 16d to be read from the storage device.
When sending the packet, the server 11 multiplies the sum voice signal included in the data addressed to the portable voice radio apparatus 16a by a coefficient of Vs / Vta. Similarly, the sum voice signal included in the data addressed to the portable voice radio apparatus 16b is multiplied by a coefficient of Vs / Vtb. The same applies hereinafter.

Thus, the level of the audio signal output toward the noise suppression type microphone earphone 25 is constant even if the model of the portable audio radio apparatus 16 is changed.
By the way, when considering a call system in a high noise environment, it is a microphone earphone that is a device used by a caller during a call because the caller is exposed to noise, so this microphone earphone should have a noise-free structure in principle. Thus, it is possible to realize a system capable of making a call even under high noise.

  Call voice is converted into various states on the transmission line during transmission, for example, air vibration, analog electrical signal, digital electrical signal, packetized information, etc., of which air noise is affected by external noise. It is a transmission part that is opened inside. It is therefore necessary to make this transmission part a dedicated closed area. To make a call without being bothered by noise in a noisy environment, there must be no noise in the other party's voice that is heard through the earphone, which is the receiving means, and there is noise in your voice that is spoken through the microphone, which is the sending means Must not be mixed.

In addition, it is required that the microphone earphone has a noise-free structure, is small enough to be unobtrusive in on-site work in a factory with a high noise environment, is easy to carry, and does not fatigue even after prolonged use. The
In response to such demands, the call system 10 has an earphone shape that is very small and can be attached to one ear, and at the same time suppresses the entry of noise that also functions as a microphone. ing. The microphone earphone 25 functions as an earphone by listening to the air vibration generated by the diaphragm when it is attached to the ear hole in the same way as a normal earphone. At the same time, unlike a normal microphone, not only from the mouth but also inside the ear hole It also functions as a microphone by capturing the air vibrations that occur in the diaphragm.

  That is, the microphone earphone 25 performs conversion from an electric signal to air vibration and vice versa by using only one diaphragm. A coil and a permanent magnet are installed in the vicinity of the diaphragm, and an electric current is passed through the coil and the diaphragm is driven by electromagnetic force to form an earphone. On the other hand, an electric field causes a current to flow to the coil by the diaphragm driven by air vibration. When it occurs, it functions as a microphone. At this time, if the signal of the driving circuit of the diaphragm goes directly to the input circuit of the microphone amplifier, it becomes a circulating circuit and howling occurs. Therefore, in order to avoid this, electrical separation is performed.

  Regarding the noise-free structure, first of all, as a countermeasure when operating as an earphone during reception, the earphone body has a sound insulation structure that is difficult to transmit external noise, and external noise enters from between the ear hole skin contacting with the earphone. Use ear pads with high adhesion to prevent earplugs. Thus, since the inside of the ear hole becomes a sealed space and a sound insulation effect is obtained, it is possible to listen to the call voice input from the earphone without being affected by the noise even under noise exceeding 90 dB. Next, when operating as a microphone, for the same reason, no noise is transmitted to the internal diaphragm, so that no noise is mixed into the transmitted voice to be output.

  In addition, for noise that has entered the microphone earphone 25 without being able to prevent intrusion, noise removal processing is performed by the noise processing circuit of the noise processing device 26 to remove voice other than the call voice as noise. Yes. This noise reduction processing is performed by measuring the background sound in the no-call voice state as noise in advance and obtaining its spectrum, but if a relatively loud sound is generated in a short time, this is considered as a voiced state. The speech spectrum is obtained from the lever part. During signal input, the noise spectral portion is always suppressed and the voice spectral portion is allowed to pass.

  As described above, the call system 10 according to the present invention uses the microphone earphone 25 having the earplug function, and forms a sealed space that is not acoustically connected to the outside air by the microphone earphone 25 and the ear hole. The sound is input to the microphone earphone 25 through the sealed space using the fact that the emitted sound is transmitted to the ear hole. Also, audio information output from the microphone earphone 25 is transmitted to the eardrum through a sealed space formed by the microphone earphone 25 and the ear hole. Furthermore, the server 11 performs processing for combining various general-purpose microphone characteristics under low noise.

As a result, it is possible to prevent noise from being mixed into the call voice, even in a high noise environment where there is a lot of noise around the caller and the noise generated by the operation of the operator, Simultaneous broadcasting and paging broadcasting are possible, and mutual communication and confirmation by voice call can be performed reliably.
Further, the microphone earphone 25 includes an echo canceller that suppresses components that enter the microphone after being delayed through the diaphragm and the sealed space as a result of operating as an earphone, reflected by the eardrum and the like.

In addition, the noise processing device 26 digitizes the input electric signal in order to reduce the noise component mixed in the input electric signal input to the microphone earphone 25, and always measures the spectrum of the background noise, Noise reduction is performed by attenuating strong points.
The microphone earphone 25 has a case in which a transducer comprising a diaphragm and a coil is installed inside a case that forms an outer shell, and a sound insulating material is packed in the surplus part after installation, and an ear pad is attached to the ear hole. By closely contacting the skin of the ear hole without any gap, the sound is prevented from leaking outside.

It is explanatory drawing which shows roughly the structure of the telephone system which concerns on one embodiment of this invention. It is explanatory drawing which shows roughly the other structural example of the telephone system of FIG. The flow at the time of implementing a group call is shown, (a) is a sequence chart in the case of invitation, (b) is a sequence chart in the case of participation. It is a sequence chart which shows the flow at the time of implementing broadcasting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Call system 11 Server 12 Switching hub 13a, 13b Access point 14 Fixed telephone 15a, 15b Speaker 16a-16h Portable audio | voice radio apparatus 17a-17h Dustproof headset 18a, 18b Loudspeaker broadcasting terminal 19 VoIP-GW
DESCRIPTION OF SYMBOLS 20 Existing telephone switch 21 Existing local PHS antenna 22a Public exchange telephone network 22b Mobile telephone network 22c Public PHS network 23 Mobile telephone base station 24 Public PHS antenna 25 Microphone earphone 26 Noise processing apparatus

Claims (2)

A server for performing communication control and individual terminal control;
A switching hub that constitutes a wired LAN and an access point that constitutes a wireless LAN connected to the server;
A fixed telephone and a loudspeaker broadcasting terminal connected to the switching hub;
A portable voice radio device connected to the access point;
An ear hole insertion type that is connected to the portable voice radio apparatus and that suppresses noise from entering, has a single diaphragm that converts electrical signals into air vibrations and vice versa, and prevents howling from occurring. Therefore , a microphone earphone that electrically isolates the diaphragm drive circuit , and a noise- proof headset that is equipped with a noise processing device that removes noise that has entered the microphone earphone. And
The server has level adjustment means for adjusting a received voice signal different for each portable voice radio apparatus to a level suitable for an optimum value for each portable voice radio apparatus to be connected in advance. Call system. The server has a function of performing group calls and broadcasting,
The noise processing device includes a noise processing circuit that detects and removes a signal other than a voice signal of a caller from an input signal from the microphone earphone,
The call system according to claim 1, wherein a group call under a high noise level that affects the transmitted voice as an external noise and a voice call during broadcasting are performed via the microphone earphone.

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