JP4882757B2 - Audio conference system - Google Patents

Description

  The present invention relates to an audio conference system that performs an audio conference by connecting two audio conference devices arranged at positions separated from each other, and an audio conference device used in the audio conference system.

  Conventionally, when an audio conference is performed between two points separated from each other, an audio conference device such as Patent Document 1 or Patent Document 2 is arranged at each point, and a conference person is present so as to surround the audio conference device. Hold a meeting.

  In the audio conference apparatuses of Patent Literature 1 and Patent Literature 2, a single speaker is arranged at the center of the housing so that sound is emitted from the top surface to the outside, and a different direction is set at each corner portion on the side surface as the sound collection direction. A plurality of microphones are arranged.

In such a conventional audio conference apparatus, sound generated from different directions is collected by each microphone and an audio signal is transmitted to the audio conference apparatus on the other side. On the other hand, when the voice conference device receives the voice signal collected by the other party's voice conference device, the voice conference device directly emits the sound from the speaker.
JP-A-8-298696 JP-A-8-204803

  In the above-described conventional audio conference system, the audio conferencing apparatus on the sound collection side (transmission side) collects audio in all directions around the casing with all microphones and transmits it as one sound emission audio signal. Then, the sound conferencing device on the sound emission side (reception side) applies the received sound emission sound signal to the speaker and emits the sound uniformly in all directions.

  In such a configuration, even if there are a plurality of participants in the other party's voice conference device, the sound emission sound signal received from the other party is emitted uniformly in all directions. I do not know the positional relationship of the participants who are present in the audio conference device. For this reason, it is not possible to give a sense of realism to the conference.

  Accordingly, an object of the present invention is to provide an audio conference system capable of realizing a conference with a sense of presence according to the positions of conference participants who are present at each audio conference device, and an audio conference device used for the audio system. It is in.

The audio conference system according to the present invention includes a disk-shaped housing, a plurality of unidirectional microphones arranged circumferentially in the housing, and a plurality of speakers arranged circumferentially in the housing. A voice conferencing system comprising: a plurality of audio conferencing apparatuses, and a connection unit that connects at least two of the plurality of audio conferencing apparatuses; The sound collecting beam signals having different sound collecting directions are formed from the sound collecting signals of the plurality of unidirectional microphones, and the sound collecting beam signal based on the sound generated by the conference is selected and selected according to the signal intensity. Corresponding to the sound collection beam signal, the sound collection direction is generated by detecting the sound collection direction in all the outer directions of the disk-shaped housing, and the sound emission based on the selected sound collection beam signal is generated. Associate audio signal and corresponding speaker orientation information The plurality of unidirectional microphones are on the upper surface of the housing, wherein the housing is disposed a central direction in a plan view as the sound collection direction, voice conference device on the receiving side, audio conference of the sender The sound signal for sound emission from the device and the corresponding speaker orientation information are received, a virtual sound source is set for the same orientation as the orientation of the speaker orientation information, and sound is emitted from the virtual sound source, The sound emitted from the plurality of speakers is controlled, and the plurality of speakers are installed on the lower surface side of the casing with the sound emitting direction outward from the casing.

In this configuration, the voice conference device on the transmission side collects the speech of the conference person, and acquires the orientation (sound collection direction) of the conference person with respect to the housing. Then, the sound emission sound signal based on the collected sound and the speaker orientation information are transmitted in association with each other. The audio conference device on the receiving side sets the direction of the virtual sound source with respect to the housing from the received speaker direction information, and emits sound from a plurality of speakers so that sound based on the sound output sound signal is emitted from the direction. Control the sound that is heard. Thereby, the conference person who is present at the voice conference device on the receiving side can listen as if the uttered sound is emitted from the same direction as the speaker direction in the voice conference device on the transmission side.
Also, with this configuration, the sound pickup directivity direction of the microphones closest to each other and the sound output directivity direction of the speaker are opposite to each other, making it difficult for the microphone to collect the sneak sound from the speaker. It becomes possible to detect the target speaker direction in all directions outside with higher accuracy.

  In addition, the voice conference device on the receiving side of the present invention is characterized in that it controls the amplitude and delay of the sound emitted from each speaker based on the set virtual sound source position and the positional relationship between the speakers.

  In this configuration, the sound output from each speaker is subjected to amplitude control and delay control in accordance with the positional relationship between each speaker and the virtual sound source position. More specifically, the amplitude of the emitted sound is attenuated according to the distance from the virtual sound source position, and the sound emission timing is delayed according to the distance from the virtual sound source position. Thereby, the conference person who is present in the voice conference apparatus on the sound emission side (reception side) can hear as if the sound was emitted from the virtual sound source position regardless of the direction of the voice conference apparatus.

  The voice conference device on the transmission side according to the present invention calculates the distance between the utterance position of the utterance sound and the side surface closest to the utterance position of the housing together with the speaker orientation, and the speaker orientation information from the speaker orientation and the distance. Is generated. The voice conference device on the receiving side is characterized in that a virtual sound source is set based on the direction and distance obtained from the received speaker direction information.

  In this configuration, not only the speaker orientation but also the distance from the housing to the speaker is calculated to set the virtual sound source position. Thereby, the speech position of the conferee of the voice conference device on the sound collection side can be more accurately reproduced by the voice conference device on the sound output side.

  According to this invention, since the sound is emitted from the position of the other party's conference person, the position of each conference person in the other party's invisible meeting room is known, and the sound emitted from that position is heard. By listening to, you can realize a voice conference system full of realism.

An audio conference system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an audio conference system according to the present embodiment.
2A and 2B are outline views of the audio conference apparatus used in the audio conference system of the present embodiment. FIG. 2A is a plan view and FIG. 2B is a side view. In FIG. 2, θ represents an angle that increases counterclockwise when the direction of the microphone MC1 and the speaker SP1 is 0 ° with the center of the audio conference apparatus 1 in plan view as the rotation center.
FIG. 3 is a functional block diagram of the voice conference apparatus shown in FIG.
As shown in FIG. 1, the audio conference system includes audio conference apparatuses 1A and 1B arranged in conference rooms 100A and 100B which are separated from each other, and a network 500 connecting the audio conference apparatuses 1A and 1B. Conference tables 101A and 101B are installed at substantially the center of the conference rooms 100A and 100B, respectively, and the audio conference apparatuses 1A and 1B are arranged on the conference tables 101A and 101B. These audio conference apparatuses 1A and 1B are provided with input / output I / Fs, and are connected to the network via these input / output I / Fs. For example, in such a conference room 100A, the conferees 201A and 203A are seated facing each other with the audio conference apparatus 1A in between, the conference person 201A is the speaker SP1 side of the audio conference apparatus 1A, and the conference person 203A is audio. The user sits on the speaker SP3 side of the conference apparatus 1A. In the conference room 100B, the conference members 202B and 204B are seated facing each other with the audio conference device 1B in between, the conference member 202B is the speaker SP2 side of the audio conference device 1B, and the conference person 204B is the audio conference device. Sitting on the speaker SP4 side of 1B.

  Each of the audio conference apparatuses 1A and 1B has the same specifications, and includes a disk-shaped casing 11. Specifically, the casing 11 has a circular shape in plan view, the area between the top surface and the bottom surface is narrower than the area of the middle part in the vertical direction, and the shape in side view has a ceiling from one point in the height direction. It has a shape that narrows toward the surface and narrows from the one point toward the bottom surface. That is, it has a shape having inclined surfaces on the upper side and the lower side from the one point. The top surface of the housing 11 is formed with a recess 12 having a predetermined depth that is smaller than the area of the top surface so that the center of the recess 12 in plan view coincides with the center of the top surface. Is set.

  The 16 microphones MC1 to MC16 are installed inside the top surface of the housing 11 along the side surface of the recess 12. Each of the microphones MC1 to MC16 has a center in the plan view of the audio conference device 1 as a rotation center, etc. They are arranged at an angular pitch (in this case, an interval of about 22.5 °). At this time, the microphone MC1 is in the direction of θ = 0 °, and the microphones MC1 to MC16 are arranged along the direction in which θ increases by 22.5 ° in order. For example, the microphone MC5 is disposed in the θ = 90 ° direction, the microphone MC9 is disposed in the θ = 180 ° direction, and the microphone MC13 is disposed in the θ = 270 ° direction. Further, each of the microphones MC1 to MC16 has a single directivity, and each microphone is arranged so as to have a strong directivity in the central direction as viewed from above. For example, the microphone MC1 has the direction of θ = 180 ° as the center of directivity, the microphone MC5 has the direction of θ = 270 ° as the center of directivity, and the microphone MC9 has the direction of θ = 0 (360) ° as the center of directivity. The microphone MC13 has the direction of θ = 90 ° as the center of directivity. The number of microphones is not limited to this, and may be set as appropriate according to specifications.

  The four speakers SP1 to SP4 are respectively installed so that the inclined surface on the lower side of the housing 11 and the sound emitting surface coincide with each other, and the speakers SP1 to SP4 rotate around the center of the audio conference apparatus 1 in plan view. The centers are arranged at equiangular pitches (in this case, intervals of about 90 °). At this time, the speaker SP1 is arranged in the same θ = 0 ° direction as the microphone MC1, the speaker SP2 is arranged in the same θ = 90 ° direction as the microphone MC5, and the speaker SP3 is arranged in the same θ = 180 ° direction as the microphone MC9. The speaker SP4 is arranged in the same θ = 270 ° direction as the microphone MC13. The speakers SP1 to SP4 have strong directivity in the front direction of the sound emitting surface. The speaker SP1 emits sound around the θ = 0 ° direction, and the speaker SP2 centers around the θ = 90 ° direction. The speaker SP3 emits sound around the θ = 180 ° direction, and the speaker SP4 emits sound around the θ = 270 ° direction.

  As described above, the speakers SP1 to SP4 are arranged on the lower side of the casing 11, the microphones MC1 to MC16 are arranged on the upper side of the casing 11, and the sound collection direction of the microphones MC1 to MC16 is the center direction of the casing 11. This makes it difficult for the microphones MC1 to MC16 to collect the wraparound sound from the speakers SP1 to SP4. For this reason, it becomes difficult to be influenced by the wraparound sound in the speaker position detection described later, and the speaker position can be detected with higher accuracy.

The operation unit 29 is installed on an inclined surface on the upper side of the housing 11 and includes various operation buttons and a liquid crystal display panel (not shown).
The input / output I / F is an inclined surface on the lower side of the housing 11 and is installed at a position where the speakers SP1 to SP4 are not installed. Although not shown, a network connection terminal, a digital audio terminal, an analog audio terminal, etc. Is provided. Then, a network cable is connected to the network connection terminal to connect to the network 500 described above.

The audio conference apparatus 1 has a functional configuration as shown in FIG. 3 in addition to such a structural configuration.
The control unit 20 performs general control such as setting, sound collection, and sound emission of the audio conference apparatus 1, and gives control to each unit of the audio conference apparatus 1 based on the operation instruction content input by the operation unit 29.

(1) Sound release The communication control unit 21 acquires voice data from the voice communication data from the other party's voice conference apparatus received via the input / output I / F, and outputs the voice data as the voice signals S1 to S3 for the channel CH1. Output to ~ CH3. At this time, the communication control unit 21 acquires the counterpart device ID from the voice communication data, and allocates a channel CH for each counterpart device ID. For example, when there is one connected counterpart device, the audio data from the counterpart device is assigned to the channel CH1 as the sound output sound signal S1. Further, when there are two connected counterpart devices, the audio data from the two counterpart devices are individually assigned to the channels CH1 and CH2 as sound emission sound signals S1 and S2, respectively. Similarly, when there are three connected counterpart devices, the audio data from the three counterpart devices are individually assigned to channels CH1, CH2, and CH3 as sound emission sound signals S1, S2, and S3, respectively. . Channels CH <b> 1 to CH <b> 3 are connected to the sound emission control unit 22 via the echo cancellation unit 28.
The communication control unit 21 extracts the speaker orientation data Py (Pm) in the destination voice conference device associated with each voice data of the voice communication data, and gives it to the sound emission control unit 22 together with the channel information.

  The sound emission control unit 22 generates speaker output signals SPD1 to SPD4 to be given to the speakers SP1 to SP4 based on the sound signals for sound emission S1 to S3 and the speaker orientation information Py.

FIG. 4 is a block diagram illustrating a main configuration of the sound emission control unit 22 of the present embodiment.
FIG. 5A is a diagram illustrating a distribution of virtual sound sources set by the sound emission specification control unit 220. FIG. 5B shows the contents of the sound emission specification table 2281.

  As shown in FIG. 4, the sound emission control unit 22 includes individual sound emission signal generation units 221 to 223 corresponding to the sound emission sound signals S1 to S3, a sound emission specification control unit 220, and speaker output signals SPD1 to SPD4. , And a memory 228 for storing a sound emission specification table 2281.

  The sound emission specification control unit 220 sets a virtual sound source based on the speaker orientation information Py from the communication control unit 21. As shown in FIG. 5A, the virtual sound source is set at a predetermined distance from the casing 11 in the horizontal direction outward and at 45 ° intervals with the center of the casing 11 as the center of rotation. ing. More specifically, the virtual sound source 901 is set in the direction of θ = 0 °, which is the direction in which the speaker SP1 and the microphone MC1 are arranged from the center of the housing 11, and 45 from the virtual sound source 901 in the counterclockwise direction. Virtual sound sources 902 to 908 are sequentially set at intervals of °. The number of virtual sound sources is not limited to this, and may be set as appropriate according to the device specifications.

  The sound emission specification control unit 220 reads the delay adjustment amount D and the gain adjustment amount G for setting the corresponding virtual sound source from the sound emission specification table 2281 stored in the memory 228 based on the set virtual sound source. For example, if the speaker orientation information Py indicates the direction of θ = 0 °, the sound emission specification control unit 220 is set with the virtual sound source 901, the delay adjustment amount D11 for SP1, the gain adjustment amount G11, and SP2. Delay adjustment amount D21, gain adjustment amount G21, SP3 delay adjustment amount D31, gain adjustment amount G31, SP4 delay adjustment amount D41, and gain adjustment amount G41 are read. Here, the delay adjustment amount D and the gain adjustment amount G are preset according to the distance between the virtual sound source to be set and the speakers SP1 to SP4. Further, these adjustment amounts may be set by performing an experiment for measuring the sound emission and collection environment on the spot after installing the audio conference apparatus.

  When the sound emission specification control unit 220 reads the delay adjustment amount D and the gain adjustment amount G for each of the speakers SP1 to SP4, the individual sound emission specification for the corresponding channel is based on the channel information given together with the speaker orientation information Py. The delay adjustment amount D and the gain adjustment amount G are output to any one of the signal generation units 221 to 223. For example, if the virtual sound source 901 is set and the channel information indicates CH1, the sound emission specification control unit 220 includes the SP1 delay adjustment amount D11, the gain adjustment amount G11, and the SP2 delay adjustment amount D21. The gain adjustment amount G21, the SP3 delay adjustment amount D31, the gain adjustment amount G31, the SP4 delay adjustment amount D41, and the gain adjustment amount G41 are provided to the individual sound emission signal generation unit 221.

  The individual sound emission signal generation units 221 to 223 are input from the corresponding channels CH1 to CH3 based on the delay adjustment amount D and the gain adjustment amount G for each of the speakers SP1 to SP4 given from the sound emission specification control unit 220. The sound emission sound signals S1 to S3 are subjected to delay processing and gain control, and output to the signal synthesis units 224 to 227. More specifically, the individual sound emission signal generation unit 221 includes the delay adjustment amount D1 * (*: 1 to 8 corresponding to the virtual sound sources 901 to 908) and the gain adjustment amount G1 * (*: the virtual sound sources 901 to 908). Corresponding 1 to 8), delay processing and gain control of the sound output sound signal S1 are performed and output to the signal synthesis unit 224. At the same time, the individual sound emission signal generation unit 221 includes the delay adjustment amount D2 * (*: 1 to 8 corresponding to the virtual sound sources 901 to 908) and the gain adjustment amount G2 * (*: 1 to 1 corresponding to the virtual sound sources 901 to 908). 8), delay processing and gain control of the sound output sound signal S1 are performed and output to the signal synthesis unit 225. At the same time, the individual sound emission signal generation unit 221 has a delay adjustment amount D3 * (*: 1 to 8 corresponding to the virtual sound sources 901 to 908) and a gain adjustment amount G3 * (*: 1 corresponding to the virtual sound sources 901 to 908). ˜8), delay processing and gain control of the sound output sound signal S <b> 1 are performed and output to the signal synthesis unit 226. At the same time, the individual sound emission signal generation unit 221 has a delay adjustment amount D4 * (*: 1 to 8 corresponding to the virtual sound sources 901 to 908) and a gain adjustment amount G4 * (*: 1 corresponding to the virtual sound sources 901 to 908). ~ 8), delay processing and gain control of the sound output sound signal S1 are performed and output to the signal synthesis unit 227. The individual sound emission signal generation units 222 to 223 perform processing similar to that of the individual sound emission signal generation unit 221 and perform delay processing and gain control of the sound output sound signals S2 and S3, and output them to the signal synthesis units 224 to 227.

  The signal synthesizer 224 synthesizes (adds) the SP1 signals output from the individual sound emission signal generators 221 to 223, and outputs the SP1 audio signal SPD1. Similarly, the signal synthesis unit 225 synthesizes (adds) the SP2 signals output from the individual sound emission signal generation units 221 to 223, and outputs the SP2 audio signal SPD2. Similarly, the signal synthesis unit 226 synthesizes (adds) the SP3 signals output from the individual sound emission signal generation units 221 to 223, and outputs the SP3 audio signal SPD3. Similarly, the signal synthesis unit 227 synthesizes (adds) the SP4 signals output from the individual sound emission signal generation units 221 to 223, and outputs the SP4 audio signal SPD4.

  The D / A converter 23 performs digital-analog conversion on each of the SP audio signals SPD1 to SPD4, and the sound emission AMP (amplifier) 24 amplifies each of the SP audio signals SPD1 to SPD4 with a constant amplification factor, and each speaker Give to SP1-SP4.

  The speakers SP1 to SP4 convert the given SP audio signals SPD1 to SPD4 into sound and emit the sound.

  By performing such sound emission processing, the sound emitted from the speakers SP1 to SP4 has a predetermined delay relationship and amplitude relationship, so that the conference person feels as if the sound is emitted from the set virtual sound source. Can be given to.

(2) Sound Collection The microphones MC1 to MC16 described above collect sound from outside such as the sound generated by the conference and generate sound collection signals MS1 to MS16. Each sound collecting AMP (amplifier) 25 amplifies the corresponding sound collecting signals MS1 to MS16 with a predetermined amplification factor, and the A / D converter 26 performs analog-digital conversion on the amplified sound collecting signals MS1 to MS16 and collects them. Output to the sound control unit 27.

FIG. 6 is a block diagram showing the main configuration of the sound collection control unit 27. As shown in FIG. 6, the sound collection control unit 27 includes a direction-specific sound collection beam generation unit 271 and an output data determination unit 272.
The direction-specific sound collection beam generation unit 271 sets an appropriate combination for the sound collection signals MS1 to MS16 (digital data), and performs the delay / addition processing of the combined sound collection signals, thereby performing the above-described processing. Sound collection beam signals MB1 to MB8 are generated with the eight different directions corresponding to the virtual sound sources 901 to 908 as the sound collection directions.

The direction-specific sound collecting beam generation unit 271 includes adders 2711 to 2718.
The adder 2711 adds the collected sound signals MS1, MS2, and MS16 to generate a collected sound beam signal MB1 having strong directivity in the θ = 180 ° direction (corresponding to the virtual sound source 905). The adder 2712 adds the collected sound signals MS2, MS3, and MS4 to generate a collected sound beam signal MB2 having strong directivity in the θ = 225 ° direction (corresponding to the virtual sound source 906). The adder 2713 adds the collected sound signals MS4, MS5, and MS6 to generate a collected sound beam signal MB3 having strong directivity in the θ = 270 ° direction (corresponding to the virtual sound source 907). The adder 2714 adds the collected sound signals MS6, MS7, and MS8 to generate a collected sound beam signal MB4 having strong directivity in the θ = 315 ° direction (corresponding to the virtual sound source 908). The adder 2715 adds the collected sound signals MS8, MS9, and MS10 to generate a collected sound beam signal MB5 having strong directivity in the θ = 0 ° direction (corresponding to the virtual sound source 901). The adder 2716 adds the collected sound signals MS10, MS11, and MS12 to generate a collected sound beam signal MB6 having strong directivity in the θ = 45 ° direction (corresponding to the virtual sound source 902). The adder 2717 adds the collected sound signals MS12, MS13, and MS14 to generate a collected sound beam signal MB7 having strong directivity in the θ = 90 ° direction (corresponding to the virtual sound source 903). The adder 2718 adds the collected sound signals MS14, MS15, and MS16 to generate a collected sound beam signal MB8 having strong directivity in the θ = 135 ° direction (corresponding to the virtual sound source 904).

  Thus, in the example of the embodiment, the sound collection beam signal MB1 is associated with the virtual sound source 905, the sound collection beam signal MB2 is associated with the virtual sound source 906, and the sound collection beam signal MB3 is associated with the virtual sound source 907. The sound beam signal MB4 is made to correspond to the virtual sound source 908. Furthermore, the sound collection beam signal MB5 is associated with the virtual sound source 901, the sound collection beam signal MB6 is associated with the virtual sound source 902, the sound collection beam signal MB7 is associated with the virtual sound source 903, and the sound collection beam signal MB8 is associated with the virtual sound source 904. To correspond to. Note that the number of sound collecting beam signals to be generated is not limited to this, and can be set as appropriate according to specifications.

  The direction-specific sound collection beam generation unit 271 outputs the generated sound collection beam signals MB1 to MB8 to the output data determination unit 272.

  The output data determination unit 272 includes a maximum signal detection unit 2721 and a Select / Mix circuit 2722.

  The maximum signal detector 2721 compares the signal levels of the sound collection beam signals MB1 to MB8 and selects the sound collection beam signal having the maximum signal level. The maximum signal detection unit 2721 outputs selected beam information MBM indicating the selected sound collection beam signal to the Select / Mix circuit 2722. Further, the maximum signal detection unit 2721 outputs the direction information corresponding to the selected sound collection beam signal to the communication control unit 21 as the speaker direction information Pm.

  Based on the selected beam information MBM from the maximum signal detector 2721, the Select / Mix circuit 2722 selects the sound collecting beam signal MB designated by the information and outputs it as the output sound collecting beam signal MBS. Note that the Select / Mix circuit 2722 does not select and output only the collected sound beam signal MB specified by the selected beam information MBM, but collects adjacent to the collected sound beam signal MB specified by the selected beam information MBM. The sound beam signal MB may be mixed and output as the output sound collection beam signal MBS.

  The echo canceling unit 28 generates a pseudo-regression sound signal based on the sound output sound signals S1 to S3 with respect to the input output sound collection beam signal MBS, and the output sound collection beam signal MBS. And a post processor for subtracting the pseudo-regression sound signal from the post processor. The echo cancellation circuit subtracts the pseudo-regression sound signal from the output sound collection beam signal MBS while sequentially optimizing the filter coefficient of the adaptive filter, so that the speakers SP1 to SP4 included in the output sound collection beam signal MBS are connected to the microphone. The wraparound component to MC1 to MC16 is removed. The output sound collection beam signal MBS ′ from which the wraparound component has been removed is output to the communication control unit 21.

  The communication control unit 21 associates the output sound collection beam signal MBS ′ from which the return sound has been removed by the echo cancellation unit 28 and the speaker orientation information Pm from the sound collection control unit 27 to generate voice communication data. To the input / output I / F. The voice communication data generated in this way is transmitted to the destination voice conference apparatus via the input / output I / F and the network 500.

  With such a configuration, sound is emitted at the position of the sound emitting side audio conference apparatus corresponding to the position of the speaker with respect to the sound collecting side audio conference apparatus. It is possible to give each conference person who is present in the sound-conference device as if the speaker who is present is present in the sound-conference device. Thereby, a remote conference full of a sense of reality can be performed. At this time, regardless of the position of the virtual sound source, by emitting sound whose delay / amplitude relationship is controlled from all the speakers SP1 to SP4, respectively, rather than simply emitting sound from the speaker near the virtual sound source position, A more realistic sound source localization can be realized. For example, when sound is emitted only from a speaker close to the virtual sound source position, the sound emission direction is the virtual sound source direction. I can't hear you. However, by emitting sound from all the speakers as in the configuration of the present embodiment, there is at least one speaker that emits sound in the direction of the conference person, not the front, so that a clear sound can be heard.

Next, a specific usage example will be described with reference to the drawings.
FIG. 7 is a diagram for explaining a sound emission and collection state when the conference person 201A speaks in the situation shown in FIG.
1 and 7, in the conference room 100A, a conference person 201A is present in the θ = 0 ° direction of the audio conference apparatus 1A, and a conference person 203A is present in the θ = 180 ° direction of the audio conference apparatus 1A. is doing. In the conference room 100B, the conference person 202B is present in the θ = 90 ° direction of the audio conference apparatus 1B, and the conference person 204B is present in the θ = 270 ° direction of the audio conference apparatus 1B.

  When the conference person 201A in the conference room 100A speaks, the voice 301A is picked up by the voice conference apparatus 1A. At this time, since the sound 301A is mainly collected by the microphones MC8, MC9, and MC10, the sound collection beam signal MB5 composed of the sound collection signals of these microphones MC8, MC9, and MC10 is equal to or greater than the predetermined threshold value. . The output sound collecting beam signal MBS comprising the sound collecting beam signal MB5 is echo-cancelled and transmitted to the audio conference apparatus 1B as audio communication data together with the speaker orientation information Pm of θ = 0 °.

  When the audio conference device 1B in the conference room 100B receives the audio communication data from the audio conference device 1A, the audio conference device 1B extracts the audio data, assigns it to the channel CH1, for example, and converts it into a sound output audio signal S1. Also, the audio conference apparatus 1B extracts the speaker orientation information Pm (= Py) from the audio communication data. Since the speaker orientation information Py is θ = 0 °, the audio conference device 1B sets a virtual sound source 901 in the direction of θ = 0 °, and the delay adjustment amount D and gain adjustment amount G that realize this virtual sound source 901. Is read. At this time, the SP audio signals SPD1 to SPD4 corresponding to the speakers SP1 to SP4 have an amplitude intensity such that SP1 audio signal SP1> SP2 audio signal SP2 = SP4 audio signal SP4> SP3 audio signal SP3. The gain adjustment amount D is set, and the delay time is set so that SP1 audio signal SP1 <SP2 audio signal SP2 = SP4 audio signal SP4 <SP3 audio signal SP3. The audio conference apparatus 1B emits the SP audio signals SPD1 to SPD4 thus adjusted from the corresponding speakers SP1 to SP4. By emitting the sound in this way, the emitted sound 401A corresponding to the SP1 audio signal SPD1 becomes the emitted sound 402A corresponding to the SP2 audio signal SPD2, and the emitted sounds 403A and SP4 corresponding to the SP3 audio signal SPD3. The sound is louder than the emitted sound 404A corresponding to the audio signal SPD4. In addition, the sound is emitted in the order of the emitted sound 401A, the emitted sound 402A, the emitted sound 403A, and the emitted sound 404A. Thereby, the conference participants 202B and 204B can hear as if the sound was emitted from the virtual sound source 901. As a result, the conference persons 202B and 204B who are present on the voice conference apparatus 101B side have the conference person 201A present on the voice conference apparatus 101A side in the direction of θ = 0 °, and this conference person 201A is present on the spot. You can feel like you are speaking.

  In the above description, the case where one person is speaking has been described as an example, but the present invention can be applied even when two or more persons are speaking at the same time. In this case, the voice conference device on the sound collection side collects the voice signal of each speaker and individually gives the speaker orientation information, and the voice conference device on the sound output side is based on the acquired speaker orientation information. Multiple virtual sound sources may be set.

  In the above description, the case where communication is performed by two audio conference apparatuses has been described. However, the above-described setting of the virtual sound source is also performed when communication is performed by a plurality of audio conference apparatuses such as three or four. Can be applied. In this case, it is only necessary to individually assign a channel to each audio conference device as a communication partner, set a virtual sound source for the sound output sound signal of each channel, and perform delay processing and gain control. More specifically, the sound output voice signal S1 assigned to the channel CH1 is subjected to delay processing and gain control based on the speaker orientation information given by the corresponding first voice conference device, and each speaker SP1. A sound signal to .about.SP4 is generated. Similarly, the emitted sound signal S2 assigned to the channel CH2 is subjected to delay processing and gain control based on the speaker orientation information given by the corresponding second audio conference apparatus, and is sent to the speakers SP1 to SP4. Audio signals are generated. Furthermore, the sound emission audio signal S3 assigned to the channel CH3 is subjected to delay processing and gain control based on the speaker orientation information given by the third audio conference device corresponding thereto, and is sent to the speakers SP1 to SP4. An audio signal is generated. Thus, by synthesizing the audio signals generated for the speakers SP1 to SP4, the SP audio signals SPD1 to SPD4 are generated and emitted from the speakers SP1 to SP4. Thereby, the conference person who is present in the voice conference apparatus that emits the sound can hear the speech as if there is a conference person who is present in another first to third voice conference apparatuses.

  In the above description, the distance from the housing is the same and the virtual sound source is set only from the azimuth. However, the virtual sound source may be set using the azimuth and the distance. In this case, the sound conferencing apparatus on the sound collection side calculates the distance between each microphone and the speech position from the delay relationship of the sound signal collected by each microphone, and specifies the speech position by using at least three distances. be able to. Then, the voice conference device on the sound collection side generates speaker direction information including distance information together with the direction information, and transmits it to the sound conference device on the sound emission side. The voice conference apparatus on the sound emitting side sets a virtual sound source obtained from the direction and distance based on the received speaker direction information, and performs delay processing and gain control for realizing the virtual sound source. As a result, it is possible to reproduce the speaking position (the position of the speaking party).

It is a block diagram of the audio conference system of embodiment of this invention. It is an outline drawing of the audio conference apparatus used for the audio conference system of the embodiment of the present invention. It is a functional block diagram of the audio conference apparatus shown in FIG. It is a block diagram which shows the main structures of the sound emission control part 22 of embodiment of this invention. It is a figure which shows distribution of the virtual sound source set by the sound emission specification control part 220, and a figure which shows the content of the sound emission specification table 2281. 3 is a block diagram illustrating a main configuration of a sound collection control unit 27. FIG. It is a figure explaining the sound emission / collection state when each conference person 201A speaks in the situation shown in FIG.

Explanation of symbols

1, 1A, 1B-voice conference device, 11-housing, 12-recess, 21-communication control unit, 22-sound emission control unit, 221-223-separate sound emission signal generation unit, 224-227-signal synthesis unit 23-D / A converter, 24-sound emitting amplifier, 25-sound collecting amplifier, 26-A / D converter, 27-sound collecting control unit, 271-directional sound collecting beam generating unit, 272-output data determining unit , 28-Echo cancellation unit, 29-Operation unit, 100A, 100B-Conference room, 101A, 101B-Conference table, 201A, 203A, 202B, 204B-Conference person, 301A-Audio (acquired audio), 401A, 402A, 403A, 404A-voice (sound emitted voice), 500-network, 901-908-virtual sound source, SP1-SP4-speaker, MC1-MC16-microphone

Claims (3)

A plurality of each provided with a disk-shaped housing, a plurality of unidirectional microphones arranged circumferentially in the housing, and a plurality of speakers arranged circumferentially in the housing An audio conference system, and a connection means for connecting at least two of the plurality of audio conference devices,
The audio conferencing device on the sending side
A sound collecting beam signal having a different sound collecting direction is formed from the sound collecting signals of the plurality of unidirectional microphones, and a sound collecting beam signal based on the sound generated by the conference is selected based on the signal intensity
Corresponding to the selected sound collecting beam signal, detecting the sound collecting direction in all the outer directions of the disk-shaped housing to generate speaker direction information,
Transmitting the sound signal for sound emission based on the selected sound collecting beam signal and the corresponding speaker orientation information,
The plurality of unidirectional microphones are installed on the upper surface side of the casing as a sound collection direction with a central direction in plan view of the casing.
The audio conferencing device on the receiving side
Receiving the voice signal for sound emission from the voice conference device on the transmitting side and the corresponding speaker orientation information;
Set a virtual sound source for the same direction as the direction of the speaker orientation information, and control the sound emitted from the plurality of speakers as emitted from the virtual sound source ,
The audio conferencing system , wherein the plurality of speakers are installed on a lower surface side of the housing with a sound emitting direction outward from the housing .   The audio conference system according to claim 1, wherein the audio conference device on the receiving side performs amplitude control and delay control of sound emitted from each speaker based on the set virtual sound source position and the positional relationship between the speakers. The voice conference device on the transmitting side is
Calculate the distance between the utterance position of the utterance and the side surface closest to the utterance position of the housing together with the sound collection direction, and generate the speaker direction information from the sound collection direction and the distance,
The receiving side audio conferencing apparatus comprises:
The audio conference system according to claim 1, wherein the virtual sound source is set based on the direction and the distance obtained from the received speaker direction information.

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