JP4400490B2 - Loudspeaker equipment, loudspeaker system - Google Patents

Description

  The present invention relates to a loudspeaker device that performs a hands-free call.

  2. Description of the Related Art Conventionally, there is a loudspeaker intercom apparatus that uses an echo canceller for suppressing the acoustic echo component of each terminal in order to solve the one-way communication performance by a voice switch.

In addition, there is a howling prevention device or a voice communication device using an echo canceller and a voice switch in combination.
JP-A-11-275243 JP-A-5-75500 JP-A-8-335977

  In the case of a loudspeaker intercom device, the amount of acoustic echo is clearly greater than in the case of a handset call. Therefore, the acoustic echo component that returns to the echo canceller with respect to the received voice signal transmitted from the echo canceller in the configuration of Patent Document 1 is clearly increased. If the amount of the acoustic echo component is suppressed below the normal operation range of the echo canceller, a simultaneous two-way call can be established stably only with the echo canceller.

  However, if the speaker output volume is increased to ensure that the received voice from the speaker of the loudspeaker intercom device is at a sufficient volume, the amount of acoustic echo that returns to the microphone increases as the volume increases, and the echo canceller can easily operate normally. An acoustic echo component exceeding the range capability will be returned. In such a system, there is a problem that the echo canceller cannot operate stably and causes howling. The noise that is particularly affected is the ambient noise that is sufficiently smaller than the transmission of the other terminal (however, if the echo canceller has a function that works when the volume is below a certain level) It shall be ambient noise above the value level). At the timing when only the ambient noise is not transmitted on the other party's terminal side, this system has also been established against this ambient noise, so there is a problem of causing howling starting from a slight noise. It was.

  An example of the other party's ambient noise is the noise of a car or the like when a loudspeaker intercom device is installed outdoors along the road.

  In the configuration of Patent Document 2, in order to secure the sufficient reception volume, it is necessary to increase the attenuation amount of the attenuation circuit in particular. However, in this premise, the attenuation tends to be increased during the most important double talk (during simultaneous transmission from each other's terminal) where it is possible to feel bidirectional simultaneous communication. In use, there was a problem that it felt like a one-way call with strong voice.

  The configuration of Patent Document 3 also includes a transmission attenuator as in the case of the attenuation circuit of Patent Document 2, and it is mentioned that the attenuation amount is automatically set to the minimum value. Is fixed based on the pre-measured result, so that it is possible to write in one-way communication characteristics due to this attenuation during double talk and flexibility to adapt to changes in the surrounding environment. There is a problem that it is necessary to have the appropriate value in advance.

  The present invention has been made to solve the above-described conventional problems, and can ensure simultaneous communication during double talk without causing howling in response to ambient noise, and aims to attenuate echo components. It is intended to provide a loudspeaker intercom device that does not require prior measurement of the appropriate value, and that makes it difficult for the sound from the terminal side that requires the secrecy of ambient sounds to leak to the other side It is.

  The loudspeaker device of the present invention is a loudspeaker device that is connected by a transmission line and performs a hands-free call using a speaker and a microphone provided in the terminal, and transmits and receives voices to and from other terminals via the transmission line. A digital communication interface that transmits and receives signals, an echo canceller that suppresses its own acoustic echo component by performing optimal control according to the state of the acoustic echo component as needed, and a digital audio signal to an analog audio signal In addition, a codec that converts an analog voice signal into a digital voice signal, a receiver amplifier that controls the gain of a received voice signal transmitted from the partner terminal, and a transmitter that controls the gain and impedance of the transmitted voice signal received by the microphone. An amplifier is provided, and if the received voice signal and sent voice signal are compared and it is determined that the incoming call is being received, the sent voice signal When it is determined to be greatly attenuated and the transmission is in progress, a voice switch that greatly attenuates the received voice signal and the magnitude of the transmitted voice signal output from the voice switch are determined according to a preset threshold value, and the result is determined. The level detection unit that can output, and while the level detection unit is determined to be small, the received voice signal from the codec is switched to the voice switch side, and while the level detection unit is determined to be large, from the codec A first switching unit that switches a received voice signal to a path side that does not pass through the voice switch; and while the level detection unit determines that the received voice signal is small, the received voice signal from the voice switch side is switched to the receiver amplifier, While it is determined to be large, a second switching unit that switches the received voice signal from the first switching unit side to the receiving amplifier is provided.

  With this configuration, depending on the level of the transmitted voice signal output from the voice switch, the voice switch control function is used for the small period, and the voice switch control function is stopped for the large period. Attenuation control can be stopped.

  Furthermore, the loudspeaker apparatus according to the present invention includes a notification unit that notifies the user of the terminal while the level detection unit determines that the level is large.

  With this configuration, it is possible to recognize whether or not the transmitted voice signal is large for the user of the loudspeaker device that is talking on the loudspeaker device. As the configuration of the notification unit, for example, various configurations such as a light-emitting unit that emits visible light and a vibration unit that vibrates and notifies a loudspeaker device can be considered.

  Furthermore, the loudspeaker apparatus according to the present invention includes a gain control unit that controls a gain determined in advance between the first switching unit and the second switching unit.

  With this configuration, it is possible to adjust the balance of the level difference between when the control function of the voice switch is operating and when it is stopped.

  The loudspeaker apparatus according to the present invention further includes a gain information communication unit that communicates information about gain via the digital communication interface, and the gain information communication unit includes the first switching unit and the second switching unit. Gain control information suitable for the information related to the gain can be output to a gain control unit provided between the gain control unit, the gain control unit can perform gain control according to the gain control information, and did.

  With this configuration, it is possible to finely adjust the amount of received voice signal that is wasted during double talk so that the level error of the received voice signal that occurs depending on the type of the other party loudspeaker apparatus is not loud. Here, the gain information communication unit may communicate the gain information itself as the information about the gain, or may communicate the terminal type information. By acquiring information on the type of the communication partner terminal, the voice communication device can determine gain information from the information on the terminal type.

  The loudspeaker communication system of the present invention includes a loudspeaker device that performs hands-free communication with a speaker and a microphone provided in a terminal, and a speech device that is connected to the loudspeaker device and a transmission line. A digital communication interface that transmits and receives voice signals for transmission / reception between terminals via the transmission line, a codec that converts digital voice signals into analog voice signals and analog voice signals into digital voice signals, and transmission from a partner terminal A reception amplifier for controlling the gain of the received voice signal, a transmission amplifier for controlling the gain and impedance of the transmission voice signal received by the microphone, and comparing the reception voice signal and the transmission voice signal during reception. If it is judged, the transmission voice signal is greatly attenuated. If it is judged that the transmission is in progress, the reception voice signal is greatly reduced. A voice switch to be output, a level detection unit capable of determining the magnitude of a transmitted voice signal output from the voice switch according to a preset threshold value, and outputting the result, and determining that the level detection unit is small The first switching for switching the received voice signal from the codec to the voice switch side while switching the received voice signal from the codec to the path side not passing through the voice switch while determining that the received voice signal is large. And the level detection unit switch the received voice signal from the voice switch side to the receiving amplifier while the level detection unit determines that the level is low, and receive the signal from the first switching unit side while the level detection unit determines that the level is high. A second switching unit that switches the voice signal to the receiver amplifier, and the loudspeaker device performs optimal control by performing correction tracking according to the state of the acoustic echo component at any time. And it has a configuration in which an echo canceller for suppressing acoustic echo component of the partner apparatus while suppressing its own acoustic echo component.

  With this configuration, similar to the loudspeaker device of the present invention, it is possible to reduce the occurrence of howling and realize simultaneous conversation using double talk. Further, since the echo component can be removed by providing the echo canceller in either the voice communication device or the telephone device, a simple configuration in which either of the voice communication device or the telephone device is omitted can be achieved.

  As described above, the present invention can ensure simultaneous communication during double talk without causing howling in response to ambient noise, and requires prior measurement of an appropriate value for the purpose of attenuation of echo components. Furthermore, it is possible to make it difficult for the sound from the terminal side that requires the secrecy of ambient sounds to leak to the other party side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
A first embodiment of the present invention will be described with reference to FIG. In the following description, a loudspeaker intercom terminal will be described as an example of a loudspeaker call device.

  FIG. 1 illustrates each of the loudspeaker interphone terminals 1-n (n = 1, 2,..., N) (hereinafter referred to as the loudspeaker interphone terminal 1-1 and the loudspeaker interphone terminal 1-2) connected to each other via the transmission line 100. ). The loudspeaker intercom apparatus is a loudspeaker interphone apparatus that includes a speaker 6-1 and a microphone 7-1 and performs hands-free communication with each other. The loudspeaker interphone terminals 1-1 communicate with each other through the transmission line 100. Digital communication interface 2-1 for transmitting and receiving voice signals for transmission / reception between intercom terminals, echo canceller 3-1 for suppressing its own acoustic echo component, digital voice signals into analog voice signals and analog voice signals The codec 4-1 for converting to a digital audio signal, the reception amplifier 5-1 for controlling the gain of the reception audio signal transmitted from the partner loudspeaker intercom terminal 1-2, and the transmission audio signal received by the microphone 7-1. A transmission amplifier 8-1 for controlling gain and impedance is provided.

  If the received voice signal and the transmitted voice signal are compared to the loudspeaker intercom terminal 1-1 that requires the confidentiality of the surrounding sound, and the received voice signal is determined to be being received, the transmitted voice signal is greatly attenuated, If it is determined, the voice switch 10-1 for greatly attenuating the received voice signal and the magnitude of the transmitted voice signal output from the voice switch 10-1 are determined according to a preset threshold value, and the result is output. While the level detection unit 9-1 and the level detection unit 9-1 that are capable of performing the determination are small, the received voice signal from the codec 4-1 is switched to the voice switch 10-1 side and is determined to be large. In the meantime, the switching unit 11-1 that switches the received voice signal from the codec 4-1 to the path side that does not pass through the voice switch 10-1, and the voice switch 10- while the level detection unit 9-1 determines that it is small. 1 side or A switching unit 12-1 for switching the received voice signal from the switching unit 11-1 side to the receiving amplifier 5-1 while switching the received voice signal to the receiving amplifier 5-1. Yes.

  When the echo canceller 3-1 has a function of suppressing a line echo component including an acoustic echo component on the counterpart terminal side in addition to the acoustic echo, the counterpart loudspeaker interphone terminal 1-2 includes an echo canceller 3-2. There is no need, and the configuration may be such that it is provided on either the loudspeaker interphone terminal 1-1 side including the voice switch 10-1 or the loudspeaker interphone terminal 1-2 side not including the voice switch 10-1.

  In addition, two or a plurality of voice intercom terminals connected to the transmission line 100 can be connected, and the terminal in the case of a plurality of terminals has a system configuration capable of talking with all other terminals connected by the transmission line. May be.

  On the other hand, the echo canceller 3-1 has a function of performing an optimal echo cancellation by correcting and tracking according to the state of the acoustic echo component at any time. Also, the voice switch 10-1 is set to operate so as to greatly attenuate the transmitted voice signal when there is no sound in both directions.

  Next, each call state will be described.

  In the two-way hands-free call state between the loudspeaker interphone terminal 1-1 and the loudspeaker interphone terminal 1-2, first, the loudspeaker interphone terminal 1-1 is listening to the voice during the transmission from the loudspeaker interphone terminal 1-2. The operation in this case will be described.

  In this case, since the transmitted voice signal is sufficiently small, it is greatly attenuated by the operation of the voice switch 10-1, and the determination of the level detection unit 9-1 is small. Therefore, the analog received voice signal output from the codec 4-1 passes through the voice switch 10-1, and the voice switch 10-1 performs more reliable attenuation on the transmitted voice signal side. Even if a sufficient received voice signal is transmitted from the speaker 6-1 during this state, the acoustic echo component picked up by the microphone 7-1 by the acoustic echo 30-1 is sufficiently attenuated by the voice switch 10-1. . Therefore, the level detector 9-1 does not erroneously determine that the level is large in response to the acoustic echo component of the received voice signal, and the echo canceller 3-1 passes through the codec 4-1 as a sufficiently attenuated acoustic echo component. Therefore, the echo canceller 3-1 can stably suppress the acoustic echo component within the capability of the normal operation range. On the other hand, during this operation, the loudspeak loudspeaker intercom terminal 1-1 becomes almost one-way call (voice reception state) for practical use, but ambient sound other than the transmitted voice to be passed (for example, room ambient sound) is loudspeaker intercom terminal. It is also a state which does not leak to 1-2.

  Next, the operation in the case of transmitting from the loudspeaker intercom terminal 1-1 or during double talk will be described.

  Only when the transmitted voice that sufficiently overcomes the acoustic echo 30-1 from the speaker 6-1 is emitted, the voice switch 10-1 determines that the voice is transmitted, greatly attenuates the received voice signal side, and transmits the transmitted voice. Eliminate signal side attenuation. As a result, the transmitted voice signal output from the voice switch 10-1 becomes larger, so that the level detector 9-1 determines that it is large. At the same time, the switching of the switching units 11-1 and 12-1 causes the received voice signal to stop passing through the voice switch 10-1, so that the large attenuation of the received voice signal is also quickly released.

  Therefore, only during this state, a two-way simultaneous call is established.

  On the other hand, at this moment, the echo canceller 3-1 returns an acoustic echo component that exceeds the capability of the normal operation range, but since the transmitted voice signal is stronger than that, the transmission state that the echo canceller 3-1 has. A slight received voice signal attenuation effect is inserted into the transmission voice signal, and it operates without problems during the period of the transmitted voice signal that does not last for a long time.

  When the transmission is completed, the level detection unit 9-1 promptly determines that the level is small, so that the path of the received voice signal immediately passes through the voice switch 10-1. Therefore, the transmitted voice signal is rapidly attenuated greatly, and again returns to an almost one-way call (voice reception state) in actual use.

  Finally, a case where the loudspeaker interphone terminals 1-1 and 1-2 do not transmit each other and the loudspeaker interphone terminal 1-2 has ambient noise such as noise will be described.

  Since no voice is transmitted on the loudspeaker intercom terminal 1-1 side, a one-way call (voice reception state) is set as described above. Since the signal from the microphone 7-1 is sufficiently attenuated by the voice switch 10-1 during this state, the loudspeaker intercom terminal that has passed beyond the level of the noise removal function possessed by the codec 4-1 or the like. The component of the acoustic echo 30-1 of ambient noise from the 1-2 side is also sufficiently attenuated. Therefore, the acoustic echo component of this noise is normally suppressed by the echo canceller 3-1.

  As described above, the loudspeaker intercom apparatus according to Embodiment 1 of the present invention can ensure simultaneous communication during double talk without causing howling in response to ambient noise, and is suitable for the purpose of attenuation of echo components. It is possible to make it difficult for the sound from the terminal side, which does not require prior measurement of the value, and further requires the secrecy of ambient sounds, to leak to the other party side.

[Embodiment 2]
A second embodiment of the present invention will be described with reference to FIG.

  In the loudspeaker interphone terminal 1-1 having the voice switch 10-1 and the level detection unit 9-1, while the level detection unit 9-1 determines that the level is large, it is visible to the user who is talking on the terminal. A light emitting unit 13-1 that emits light is provided.

  As described above, the loudspeaker intercom apparatus according to the second embodiment of the present invention transmits the attenuation state of the transmitted voice signal of the voice switch 10-1 that is not canceled unless a reliable voice is emitted on the loudspeaker interphone terminal 1-1 side. Therefore, it is possible to prompt the transmitter to emit the transmitted voice surely.

  In the present embodiment, an example is described in which a light emitting unit is provided in order to make the speaker recognize the attenuation state of the transmitted voice signal. However, the attenuation state of the transmitter can be recognized by a configuration other than the light emitting unit. Also good. For example, the structure etc. which vibrate a loudspeaker intercom apparatus are also possible.

[Embodiment 3]
A third embodiment of the present invention will be described with reference to FIG.

  The loudspeaker interphone terminal 1-1 including the voice switch 10-1 and the level detection unit 9-1 includes a gain control unit 14-1 that controls a predetermined gain between the switching units 11-1 and 12-1. ing.

  As described above, the loudspeaker intercom apparatus according to the third embodiment of the present invention can adjust the balance of the level difference from the received voice signal that is attenuated momentarily by the control function of the voice switch 10-1 according to the sense of hearing.

[Embodiment 4]
A fourth embodiment of the present invention will be described with reference to FIG.

  Each terminal includes a terminal determination unit 15-1 that performs communication of each terminal type or direct gain information via the digital communication interface 2-1, and further includes a voice switch 10-1 and a level detection unit 9-. 1, the terminal determination unit 15-1 outputs gain control information suitable for the communication information to a gain control unit 14-1 provided between the switching units 11-1 and 12-1. The gain control unit 14-1 can perform gain control according to the gain control information.

  As described above, the loudspeaker intercom apparatus according to the fourth embodiment of the present invention reduces the amount of received voice signal that is wasted during double talk to the level error of the received voice signal that is generated depending on the type of each other loudspeaker intercom terminal. Fine adjustments can be made to prevent loudening.

  As described above, the present invention can ensure simultaneous communication during double talk without causing howling in response to ambient noise, and can perform appropriate prior measurement for the purpose of attenuation of echo components. In addition, it is possible to make it difficult for the sound from the terminal side that requires the secrecy of the surrounding sound to leak to the other party side, which is useful as a loudspeaker intercom apparatus or the like for performing a hands-free call.

The block diagram of the loudspeaker intercom apparatus of the 1st Embodiment of this invention The block diagram of the loudspeaker intercom apparatus of the 2nd-4th embodiment of this invention

Explanation of symbols

1-1, 1-2 Loudspeaker interphone terminal 2-1, 2-2 Digital communication interface 3-1, 3-2 Echo canceller 4-1, 4-2 Codec 5-1, 5-2 Receiver amplifier 6-1, 6-2 Speakers 7-1 and 7-2 Microphones 8-1 and 8-2 Transmitting amplifier 9-1 Level detector 10-1 Voice switch 11-1 Switching unit 12-1 Switching unit 13-1 Light emitting unit 14- DESCRIPTION OF SYMBOLS 1 Gain control part 15-1,15-2 Terminal determination part 20-1 Gain control part 30-1,30-2 Acoustic echo 100 Transmission path

Claims (5)

A loudspeaker device connected by a transmission line and performing a hands-free call with a speaker and a microphone provided in the terminal,
A digital communication interface for transmitting and receiving voice signals for transmission and reception with other terminals via the transmission path;
An echo canceller to suppress the acoustic echo component of its own by performing an optimal control by correcting and tracking according to the state of the acoustic echo component at any time,
A codec for converting a digital audio signal into an analog audio signal and an analog audio signal into a digital audio signal;
A receiver amplifier for controlling the gain of the received voice signal transmitted from the other terminal;
A transmission amplifier for controlling the gain and impedance of the transmission voice signal received by the microphone;
A voice switch that greatly attenuates the transmitted voice signal when it is determined to be receiving by comparing the received voice signal and the transmitted voice signal;
A level detector capable of determining the magnitude of the transmitted voice signal output from the voice switch according to a preset threshold value and outputting the result;
The received voice signal from the codec is switched to the voice switch side while the level detector determines that it is small, and the received voice signal from the codec is not passed through the voice switch while it is determined to be large. A first switching unit for switching to the route side;
The received voice signal from the voice switch side is switched to the receiving amplifier while the level detector determines that the level is low, and the received voice signal from the first switch side is determined while the level detector is determined to be high. A second switching unit for switching to the receiver amplifier;
A loudspeaker device characterized by comprising:   The loudspeaker apparatus according to claim 1, further comprising a notification unit that notifies a user of the terminal while the level detection unit determines that the level is large.   The loudspeaker apparatus according to claim 1 or 2, further comprising a gain control unit that controls a gain predetermined between the first switching unit and the second switching unit.   A gain information communication unit configured to communicate gain-related information via the digital communication interface, the gain information communication unit including a gain control provided between the first switching unit and the second switching unit; The loudspeaker call according to claim 3, wherein gain control information adapted to the gain-related information can be output to a unit, and the gain control unit can perform gain control according to the gain control information. apparatus. A loudspeaker device that performs a hands-free call with a speaker and a microphone provided in a terminal, and a speech device connected to the loudspeaker device and a transmission path,
The loudspeaker apparatus includes a digital communication interface that transmits and receives voice signals for transmission / reception between terminals via the transmission line, and a codec that converts a digital voice signal into an analog voice signal and an analog voice signal into a digital voice signal. A receiving amplifier that controls the gain of the received voice signal transmitted from the partner terminal, a transmitting amplifier that controls the gain and impedance of the transmitted voice signal received by the microphone, and the received voice signal and the transmitted voice signal. If it is determined that the call is being received, the transmitted voice signal is greatly attenuated. If it is determined that the call is being transmitted, the received voice signal is greatly attenuated, and the transmitted voice signal output from the voice switch is A level detector that can determine the magnitude according to a preset threshold and output the result, and the level detector The received voice signal from the codec is switched to the voice switch side while the codec is determined to be large, and the received voice signal from the codec is switched to the path side that does not pass through the voice switch while it is determined to be large. The switching unit and the level detection unit switch the received voice signal from the voice switch side to the receiving amplifier while it is determined to be small, and from the first switching unit side while it is determined to be large. A second switching unit that switches the received voice signal to the receiver amplifier,
The loudspeaker device has an echo canceller that suppresses the acoustic echo component of the counterpart device and suppresses the acoustic echo component of the counterpart device while performing optimal control by correcting and tracking according to the state of the acoustic echo component at any time. A voice call system characterized by