JP4308079B2 - Electroacoustic device - Google Patents

Description

  The invention of the present application provides a synthesized signal obtained by synthesizing output signals of a plurality of microphones individually as a voice to a user of the microphone, and also provides electricity to a person other than the microphone user as a voice. The present invention relates to an acoustic device.

  It is required to synthesize the output signals of a plurality of microphones, convert the synthesized signals into sound and provide them individually to the user of the microphone, and to provide the synthesized signals as sound to persons other than the microphone user. There is a sound field. A typical example is a conference hall.

  For example, when a meeting of a certain parliament is held in a certain conference hall, a member of this parliament becomes a participant in the meeting. In the conference hall, in addition to the members who are participants in the conference, for example, there may be listeners in the auditorium.

  The remarks of each member who participates in the meeting must be heard by other members and the listener. In addition, each member who participates in the conference must clearly hear what other members have said.

  Therefore, a device called a speaker unit may be provided in each seat.

  The speaker unit is provided with a microphone and a small speaker. The speech of each member is received by the microphone of the speaker unit, and is amplified from the speaker of the speaker unit in the seats of other members.

  In addition, the speech of each member of the parliament is received by the microphone of the speaker unit, and is also amplified from a speaker for providing voice to substantially the entire range of the conference hall. As a result, not only other members of the parliament but also the listener can hear the remarks.

  In a meeting, a small number of members may speak at the same time (including a case where only one member speaks), or a large number of members may speak at the same time. When a small number of members of the council speak at the same time, the level is small even if the voices of all the speakers are synthesized. When many members of the council speak at the same time, synthesizing the voices of all the speakers increases the level.

  The listener wants to hear the contents of the meeting in a natural voice as well as listening to each member's remarks. For this reason, it is desirable to synthesize the voices of all the members who speak from a speaker that provides voices over almost the entire range of the conference hall, and naturally synthesize the synthesized voices without processing them.

  However, if the speeches of all members who speak are synthesized, and the synthesized speech is expanded without processing the synthesized speech, the speech may be difficult to hear. One of the causes is that the speaker unit speaker is small. In other words, the speaker unit is generally provided with a volume for adjusting the volume of the speaker, but if this volume is adjusted assuming that a small number of members are speaking, When speaking, the loud sound of the speaker may be distorted. Also, if this volume is adjusted assuming that a large number of lawmakers speak, there will be a situation where the loud sound from the speakers is too low when a small number of lawmakers speak. Also, this problem may be avoided by adjusting the volume each time according to the number of speakers, but such volume adjustment is very troublesome.

A conference apparatus using an echo control technique has also been proposed (for example, Patent Document 1). When this apparatus is used in a conference hall where large echoes are generated, it is possible to prevent a degree of speech intelligibility from being lowered due to echoes to some extent. However, each member cannot be clearly told what other members have to say.
Japanese Patent Laid-Open No. 5-7170

  The object of the present invention is to enable the voices of a plurality of speakers to be naturally amplified over a substantially entire range of the sound field with a sense of reality, while each speaker has sufficient content of other speakers. It is an object of the present invention to provide an electroacoustic apparatus that can be understood.

In order to solve the above problems, an electroacoustic apparatus according to the present invention is an electroacoustic apparatus provided in a conference hall, and includes a plurality of microphones, mixing means, a first speaker, automatic gain adjusting means, An electroacoustic transducer provided corresponding to at least one of the plurality of microphones, the plurality of microphones corresponding to each of a plurality of seats for participants in the conference And the mixing means generates a synthesized signal by synthesizing the output signals of the plurality of microphones, and the first speaker converts the synthesized signal into a sound, which is an abbreviation of the conference hall. The speaker is provided to provide sound over the entire range, and the automatic gain adjusting means gives a gain to the synthesized signal and automatically adjusts the gain according to the level of the synthesized signal. Electrical acoustic transducer converts the output signal of the automatic gain control means to the audio output signal of the automatic gain control means is delivered to the electro-acoustic transducer by the second wireless communication device. That is, this electroacoustic apparatus is used as a conference hall electroacoustic apparatus.

The first speaker can convert the synthesized signal into sound with linearity and provide the sound to the sound field. On the other hand, the electroacoustic transducer provides sound whose level is adjusted by the automatic gain adjusting means. Therefore, it is possible to provide the contents of the utterances uttered toward the microphone more clearly. Further, in the wireless communication device, there is a limit to the bandwidth of the carrier frequency of the wireless signal that can be used. When audio signals are wirelessly transmitted with a large dynamic range, a wide occupied frequency band is required. Therefore, multi-channel wireless transmission becomes difficult. However, when the level of the audio signal is adjusted by the automatic gain adjusting means, the dynamic range of the audio signal can be reduced. Therefore, multi-channel radio transmission is facilitated despite the limitation of the bandwidth of the carrier frequency of the radio signal that can be used. Further, by narrowing the dynamic range and narrowing the occupied frequency band, problems such as intermodulation, second harmonic, IF interference, and IM interference are less likely to occur.

  According to the electroacoustic apparatus of the present application, it is possible to hear natural sound with a sense of presence in almost the entire range of the sound field. In addition, the user of the microphone can clearly hear the content of the speech of other microphone users.

  In the electroacoustic apparatus of the present invention, the electroacoustic transducer may be a second speaker, a headphone, or an earphone.

  The electroacoustic apparatus may be configured such that output signals of the plurality of microphones are sent to the mixing means by the first wireless communication apparatus.

  Still further, in the electroacoustic apparatus, the first wireless communication apparatus may be a first infrared wireless communication apparatus.

  Still further, in the electroacoustic device, the second wireless communication device may be a second infrared wireless communication device. In the infrared wireless device, since the limitation of the bandwidth of the carrier frequency that can be used is particularly large, the level adjustment of the audio signal by the automatic gain adjustment means is more effective.

  Hereinafter, an electroacoustic apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an internal view of a conference hall in which the electroacoustic device D1 is installed. In this conference hall, there are an area where a plurality of seats B1, B2, B3... Are provided and an area where a plurality of auditory seats C are provided. Both areas are separated by a divider P.

  In the conference hall, for example, a certain parliamentary meeting is held. Each member of the parliament sits in each seat B1, B2, B3... And becomes a participant in the conference. The observer sits in the auditory seat C. A listener cannot participate in the meeting.

  Speakers 15 are attached to the side walls of the conference hall.

  The number of seats in this conference hall is n, and one speaker unit is placed in each seat. That is, speaker units U1, U2, U3,..., Un are installed in the respective seats B1, B2, B3,. The plurality of speaker units U1, U2, U3,.

  FIG. 2 is an external view of the speaker unit U1. The speaker unit U1 includes a microphone M1 and a small speaker S1. The speaker unit U1 includes a volume V1 (not shown) and a push button switch W1. FIG. 2 shows a cylindrical knob T as an operation unit of the volume V1. The speaker unit U1 incorporates a microphone head amplifier H1 (not shown) and an amplifier A1 (not shown) for driving a small speaker.

  Referring to FIG. 1 again, for example, when a member of the seat B1 speaks, the member pushes the push button type switch W1 of the speaker unit U1 installed in the seat B1. Then, the microphone M1 of the speaker unit U1 is turned on. The microphone M1 receives a voice of a member of the parliament who speaks. The output signal of the microphone M1 is amplified by an amplifier and is amplified from the speaker 15 as the first speaker. The rated output level of the speaker 15 is relatively large. Therefore, the loud sound of the speaker 15 can be heard in almost the entire range of the conference hall.

  On the other hand, the output signal of the microphone M1 that has received the voice of the member who speaks is also amplified from a small speaker, which is an electroacoustic transducer, provided in each speaker unit U1, U2, U3,. . The rated output level of this small speaker is small. The small speaker of the speaker unit is for providing a loud sound to each member of the Diet. The volume of the small speaker can be adjusted by operating a volume knob.

  FIG. 3 is a schematic block diagram of the electroacoustic device D1. The electroacoustic device D1 mainly includes n microphones M1, M2,..., Mn, n microphone head amplifiers H1, H2,..., Hn, and n push button switches W1. , W2, n small speakers S1, S2, ..., Sn, n amplifiers A1, A2, ..., An, and n volumes V1, V2,. .., Vn, mixing device 11, automatic gain adjustment device 12, volume 13, amplifier 14, and speaker 15.

  , Mn, microphone head amplifiers H1, H2,..., Hn, push button switches W1, W2,..., Wn, and small speakers S1, S2,. .., Sn, amplifiers A1, A2,..., An and volumes V1, V2,..., Vn are members provided in the speaker units U1, U2,.

  The speaker unit U1 shown in FIGS. 1 and 2 includes the microphone M1, the microphone head amplifier H1, the push button switch W1, the small speaker S1, the amplifier A1, and the volume V1 shown in FIG. Yes. Further, the speaker unit U2 of FIG. 1 is provided with a microphone M2, a microphone head amplifier H2, a push button switch W2, a small speaker S2, an amplifier A2, and a volume V2. The speaker unit Un is provided with a microphone Mn, a microphone head amplifier Hn, a push button type switch Wn, a small speaker Sn, an amplifier An, and a volume Vn.

  Thus, the small speaker S1 is provided corresponding to the microphone M1, the small speaker S2 is provided corresponding to the microphone M2, and the small speaker Sn is provided corresponding to the microphone Mn.

  The microphone head amplifiers H1, H2,..., Hn are connected to the subsequent stages of the microphones M1, M2,..., Mn, and the push button switches W1, W2,. .., Wn are connected. The output signals of all push button switches W1, W2,..., Wn are synthesized by the mixing device 11. The synthesized signal is branched and sent to the volume 13 and the automatic gain adjuster 12. An amplifier 14 is connected to the subsequent stage of the volume 13, and a speaker 15 is connected to the subsequent stage.

  The output signal of the automatic gain adjustment device 12 is branched into n volumes V1, V2,. Amplifiers A1, A2,..., An are connected to the subsequent stages of the respective volumes V1, V2,..., Vn, and small speakers S1, S2,. ing.

  Each of the microphones M1, M2,..., Mn is turned on when the corresponding push button type switches W1, W2,. In this way, the microphones M1, M2,..., Mn are turned on when the corresponding push button switches W1, W2,. This is to avoid the occurrence. In addition, a connection switch is provided on the small speakers S1, S2,..., Sn side, and this connection switch and the push button type switches W1, W2,. .., Sn may be configured to be turned off when Mn is turned on, corresponding to the small speakers S1, S2,. With this configuration, howling is more effectively avoided between the small speakers S1, S2,..., Sn and the corresponding microphones M1, M2,. Can do.

  As described above, each of the microphones M1, M2,..., Mn is turned on when the corresponding push button switches W1, W2,. The output signals of all microphones that are turned on among the microphones M1, M2,..., Mn are synthesized by the mixing device 11. The synthesized signal is amplified by the speaker 15. The volume of the speaker 15 can be adjusted by the volume 13. The speaker 15 is a relatively large speaker and has a loud sound. Therefore, a loud sound can be provided over substantially the entire range of the conference hall. The listener can understand the contents of the conference mainly by listening to the loud sound from the speaker.

  Generally speaking, of the n microphones M1, M2,..., Mn, the greater the number of microphones in the on state, the greater the level of the synthesized signal output from the mixing device 11. That is, even if only a small number of members of the council speak at the same time, the level of the synthesized signal output from the mixing device 11 is small, but when a large number of council members speak at the same time, the level of the synthesized signal output from the mixing device 11 increases. .

  The loudness of the loud sound from the speaker 15 is roughly proportional to the magnitude of the synthesized signal output from the mixing device 11. That is, if the level of the composite signal output from the mixing device 11 is twice a reference level, the level of the loud sound from the speaker 15 is also doubled, and the composite signal output from the mixing device 11 If the level becomes a half of a reference level, the level of the loud sound from the speaker 15 also becomes a half. In this way, the synthesized signal output from the mixing device 11 is amplified from the speaker 15 with linearity.

  As a result, the listener can not only hear the contents of each member's remarks but also the natural sound of the contents of the meeting, and can fully feel the presence of the meeting.

  Since the speaker 15 is a speaker for providing a loud sound over substantially the entire range of the conference hall, its rated output is large. Even if the output level of the speaker 15 is considerably smaller than the rated output level, it is possible to provide a sound having a normal sound pressure level in the conference hall. That is, the speaker 15 has a considerable margin in the output level in the normal use state.

  When there are a large number of microphones in the on state among n microphones M1, M2,..., Mn, or when the voice of a member who speaks becomes much louder than usual, the mixing device Although the level of the synthesized signal output from 11 is considerably increased, the loudspeaker without distortion is provided from the speaker 15.

  Observers not only want to hear the content of each member, but also want to hear the natural sound of the conference. Therefore, it is desirable that the output signal (synthetic signal) of the mixing device 11 is amplified from the speaker 15 with linearity.

  On the other hand, a composite signal that is an output signal of the mixing device 11 is also sent to the automatic gain adjustment device 12. The automatic gain adjustment device 12 is also abbreviated as “AGC”, and gives gain to the input signal so that the level of the output signal is constant regardless of the level of the input signal. . That is, the gain is varied according to the level of the input signal.

  The output signal of the automatic gain adjuster 11 is amplified by each small speaker S1, S2,. The members of the respective seats B1, B2,..., Bn adjust the volume V1, V2,..., Vn of the speaker units U1, U2,. The volume of S2,..., Sn can be adjusted.

  Members of each of the seats B1, B2,..., Bn can hear the speech of other members from the small speakers S1, S,..., Sn of the speaker units U1, U2,. .

  Earlier, he explained that he wanted to hear the content of each member's remarks and to hear the natural sound of the conference. Further, it has been explained that the speaker 15 has a considerable margin in the output level in the normal use state.

  On the other hand, each member who is a participant in the conference attaches importance to clearly listening to the speech content of other members, rather than listening to the natural voice of the conference content. In addition, the small speakers S1, S2,..., Sn of the speaker units U1, U2,. That is, the small speakers S1, S2,.

  Similarly to the speaker 15, if the output signal (synthetic signal) of the mixing device 11 is to be amplified from the small speakers S1, S2,..., Sn with linearity, the small speakers S1, S2,. ..., it must be set so that the loud sound from Sn becomes considerably small. Otherwise, the loud sound from the small speakers S1, S2,..., Sn will be distorted when the level of the synthesized signal output from the mixing device 11 becomes considerably higher than normal. Because it ends up. If the loud sound from the small speakers S1, S2,..., Sn is distorted, each member of the parliament cannot clearly hear the contents of speech from other members.

  However, in the electroacoustic device D1, the output signal (synthetic signal) of the mixing device 11 is gain-adjusted by the automatic gain adjusting device 12, and then provided to the small speakers S1, S2,.

  When there are a large number of microphones in the on state among n microphones M1, M2,..., Mn, or when the voice of a member who speaks becomes much louder than usual, the mixing device The level of the composite signal output from 11 is also considerably increased. As described above, even when the level of the synthesized signal output from the mixing device 11 becomes considerably higher than that in the normal state, the synthesized signal is gain-adjusted by the automatic gain adjusting device 12, so that the small speakers S1, S2,. ..., the loud sound from Sn is not distorted. Therefore, each member of the Diet can hear the contents of other members' statements clearly.

  In addition, when the number of microphones in the on state among n microphones M1, M2,..., Mn becomes small, or the voice of a member of the parliament who speaks becomes much lower than usual, The level of the synthesized signal output from the mixing device 11 is also considerably reduced. In this way, even when the level of the composite signal output from the mixing device 11 becomes considerably smaller than normal, the composite signal is gain-adjusted by the automatic gain adjustment device 12, so that the small speakers S1, S2,. ..., the loud sound from Sn is never too low. Therefore, each member of the Diet can hear the contents of other members' statements clearly.

  In this way, appropriate gain adjustment is performed according to the level of the composite signal output from the mixing device 11, and therefore, even with small speakers S1, S2,. Each member of the Diet can always hear clearly what other members have said.

  In the electroacoustic device D1 of Example 1 described above, the audio signal adjusted by the automatic gain adjusting device 12 is provided to all the small speakers S1, S2,..., Sn.

  However, the audio signal adjusted by the automatic gain adjusting device 12 is not necessarily provided to all the small speakers S1, S2,. The audio signal adjusted by the automatic gain adjusting device 12 may be provided to a part of the small speakers S1, S2,..., Sn, or the small speakers S1, S2,. You may make it provide only to one of them.

  FIG. 4 is a schematic block diagram of the electroacoustic device D2 according to the second embodiment. The electroacoustic device D1 in FIG. 3 and the electroacoustic device D2 in FIG. 4 are different only in the following points, and the other points are the same.

  That is, in the electroacoustic device D1 of FIG. 3, the audio signal adjusted by the automatic gain adjusting device 12 is provided to all the small speakers S1, S2,. On the other hand, in the electroacoustic device D2 of FIG. 4, the audio signal adjusted by the automatic gain adjusting device 12 is provided only to the small speaker S1. The small speaker S1 is provided in the speaker unit U1, and the microphone M1 is provided in the speaker unit U1. That is, the small speaker S1 is provided corresponding to the microphone M1.

  The other small speakers S2,..., Sn are provided with the output signal of the mixing device 11 without going through the automatic gain adjusting device 12.

  In the electroacoustic device D2 of FIG. 4 as well, a speaker who uses the small speaker S1 can be provided with a loud sound whose gain is adjusted according to the level of the synthesized signal output from the mixing device 11. Therefore, the member of the council can clearly hear the contents of statements of other members of the council, even when the level of the composite signal output from the mixing device 11 is considerably higher or lower than usual.

  Although not clearly shown in the electroacoustic device D1 of the first embodiment, the output signals of the microphones U1, U2,..., Un may be sent to the mixing device 11 by the wireless communication device. Further, the output signal of the automatic gain adjustment device 12 may be sent to the small speakers S1, S2,..., Sn by the wireless communication device.

  FIG. 5 is a schematic block diagram of the electroacoustic device D3 according to the third embodiment. In this diagram, the wireless communication device 30 that sends output signals of the microphones M1, M2,..., Mn to the mixing device 11 is shown. And a wireless communication device 40 for sending the output signal of the automatic gain adjusting device 12 to the small speakers S1, S2,..., Sn. The other configuration of the electroacoustic device D3 in FIG. 5 is the same as that of the electroacoustic device D1 in FIG.

  The wireless communication device 30 is an infrared wireless communication device. The wireless communication device 30 includes a transmission unit 32 and a reception unit 34. The transmission unit 32 includes a light transmitter 33, and the reception unit 34 includes a light receiver 35. Multi-channel (n-channel) communication is performed between the transmission unit 32 and the reception unit 34 when the light receiver 35 receives infrared rays emitted from the light transmitter 33.

  The wireless communication device 40 is also an infrared wireless communication device. The wireless communication device 40 includes a transmission unit 42 and a reception unit 44. The transmission unit 42 includes a light transmitter 43, and the reception unit 44 includes a light receiver 45. Multi-channel (n-channel) communication is performed between the transmission unit 42 and the reception unit 44 when the light receiver 45 receives infrared rays emitted from the light transmitter 43.

  As previously mentioned. In the electroacoustic device D3, the output signal of the automatic gain adjusting device 12 is sent to the small speakers S1, S2,. As described above, when the audio signal is transmitted by the radio communication device 40, if the gain of the audio signal is adjusted by the automatic gain adjustment device 12, the use frequency bandwidth of the carrier wave used in the radio communication can be reduced. Is good.

  The reason is as follows. That is, in general, a wireless communication device has a limitation on the bandwidth of the carrier frequency of a wireless signal (infrared ray or radio wave) that can be used. When audio signals are wirelessly transmitted with a large dynamic range, a wide occupied frequency band is required. Therefore, multi-channel wireless transmission becomes difficult.

However, if the level of the audio signal is adjusted by the automatic gain adjustment device 12 as in the electroacoustic device D3, the dynamic range of the audio signal can be reduced. Therefore, multi-channel wireless transmission is facilitated despite the limited carrier frequency bandwidth of the wireless signal (infrared) that can be used. In addition, by narrowing the dynamic range and narrowing the occupied frequency band, problems such as intermodulation, second harmonic, IF interference, and IM interference are less likely to occur. Although it is an infrared wireless communication device, in infrared wireless communication, the limitation of the bandwidth of the carrier frequency that can be used is particularly large, so that the gain adjustment of the audio signal by the automatic gain adjustment device 12 is more effective.

  As described above, various embodiments of the electroacoustic apparatus according to the present invention have been described with reference to FIGS.

  In the first to third embodiments, the electroacoustic transducers provided corresponding to the microphones M1, M2,..., Mn are speakers (small speakers S1, S2,..., Sn). The electroacoustic transducer need not be a speaker. For example, headphones or earphones may be used as the electroacoustic transducer.

  In the third embodiment, the wireless communication devices 30 and 40 are infrared wireless communication devices, but these wireless communication devices do not have to be infrared wireless communication devices. For example, a wireless communication device using radio waves can be used.

  By using the electroacoustic apparatus of the present invention, it becomes possible to listen to natural sounds with a sense of presence in almost the entire range of the sound field, and the user of the microphone speaks what other microphone users say Can be heard clearly. Therefore, the electroacoustic device of the present invention is useful in the technical field of electroacoustics, particularly in the technical field of electroacoustic devices for conference halls.

It is a figure inside the conference hall where the electroacoustic apparatus was installed. It is an external view of a speaker unit. It is a schematic block diagram of an electroacoustic apparatus. It is a schematic block diagram of an electroacoustic apparatus. It is a schematic block diagram of an electroacoustic apparatus.

Explanation of symbols

D1, D2, D3 Electroacoustic devices M1, M2,..., Mn microphones H1, H2,..., Hn microphone head amplifiers W1, W2, ..., Wn push button type switches S1, S2,. .., Sn Small speaker A1, A2,..., An amplifier V1, V2,..., Vn Volume 11 Mixing device 12 Automatic gain adjustment device 13 Volume 14 Amplifier 15 Speaker 30, 40 Wireless communication device 32, 42 Transmission unit 33, 43 Light transmitter 34, 44 Receiver unit 35, 45 Light receiver

Claims (5)

An electroacoustic device provided in a conference hall,
A plurality of microphones, mixing means, a first speaker, automatic gain adjustment means, and an electroacoustic transducer provided corresponding to at least one of the plurality of microphones;
The plurality of microphones are microphones provided corresponding to each of a plurality of seats for participants in the conference,
The mixing means combines the output signals of the plurality of microphones to generate a combined signal,
The first speaker is a speaker provided for converting the synthesized signal into sound and providing sound to substantially the entire range of the conference hall,
The automatic gain adjusting means gives gain to the combined signal and automatically adjusts the gain according to the level of the combined signal;
The electroacoustic transducer converts the output signal of the automatic gain adjusting means into sound ,
An electroacoustic apparatus in which an output signal of the automatic gain adjusting means is sent to the electroacoustic transducer by a second wireless communication apparatus.   The electroacoustic device according to claim 1, wherein the electroacoustic transducer is a second speaker, headphones or earphones.   The electroacoustic apparatus according to claim 1 or 2, wherein output signals of the plurality of microphones are sent to the mixing means by a first wireless communication apparatus.   The electroacoustic apparatus according to claim 3, wherein the first wireless communication apparatus is a first infrared wireless communication apparatus. The electroacoustic device according to any one of claims 1 to 4, wherein the second wireless communication device is a second infrared wireless communication device.

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