JPH09261351A - Voice telephone conference device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict telephone charge and to improve caller identification by permitting a transmission path to be one channel and transmitting the sound collecting signals of respective microphones after mixing. SOLUTION: Caller position data *1 obtained by detecting a caller position from a voice input to the microphone 1 by a caller position data detecting circuit 2 is multiplexed in a caller position information multiplexing circuit 4 together with voice data *2 obtained by executing digital conversion by a voice CODEC 3 and transmitted with a line interface circuit 5. A caller position information separating circuit 6 receives it and separates it into caller position and voice data #1 and 2. A caller position reproducing circuit 8 calculates the reproduction level of a voice signal analog-converted by the voice CODEC in respective speakers 9 from data #1 so as to output it. Thus, the voice signal and caller position data are multiplexed in the 1-CH transmission path and a voice signal transmitting speaker level is decided at a reception side based on data #1 so that sound creep passage between the speaker and the microphone with the multi-CH transmission conversion of the voice signal is not increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice conference device capable of transmitting speaker position information, and more particularly, transmitting speaker position information on the transmitting side together with voice information on one transmission channel.
Based on the speaker position information and voice information on the receiving side, the voice image of each speaker is localized at each speaker position to provide a voice teleconferencing device with a sense of presence and high speaker identification. It was intended. In addition, aiming to provide a voice conference call device that can transmit the remote control information of the microphone input of the other party together with the voice information through one transmission channel, and can switch the microphone input of the other party and remotely control the input signal level. It was done.

[0002]

2. Description of the Related Art Conventionally, a voice teleconference device is generally capable of using a plurality of microphones in order to widely collect the voices of many conference participants. Since it has one channel, the signals collected by each microphone are mixed once and then transmitted.

[0003]

Therefore, on the receiving side, the sound image uttered by the conference participant is fixed and reproduced in one place, so that the identification of the speaker is poor (it is difficult to understand who is speaking). There was a problem. A method of collecting the voices of the conference participants in stereo and transmitting the voices in stereo using the 2B channel of the INS net can be considered, but this method has the following problems. (1) Since there are two transmission lines, the call charge will be doubled. (2) A plurality of microphones / speakers are always in use for stereo sound collection / reproduction, and the sound sneak path between the speakers and microphones increases, so a sound field control circuit (echo canceller) for suppressing howling. , Echo subpressor) becomes complicated and the device scale becomes large. (3) Since the two transmission paths (2B) are not synchronized, a processing circuit for achieving this synchronization is required, and the device scale becomes large. (4) On the stereo playback side, the original sound cannot be localized unless the sound is heard from the center of the left and right speakers.
Restricted at participating places.

Further, the conventional voice telephone conference device has a speaker volume adjusting function for adjusting the reproduction volume of the other party to a volume that is easy to hear on the receiving side. For example, if there are multiple people on the other side and the speaking level and the distance between the microphone and the person are different, the level of the volume input to the microphone will be significantly different. However, there was a problem in that adjustments could not be made for all people.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to realize a voice conference device having a simple device configuration and a high speaker identification characteristic which does not cause an increase in call charges. . Another object of the present invention is to realize a voice teleconference device capable of switching the microphone input of the other party and remotely controlling the input signal level.

[0006]

According to the present invention, there are provided "speaker position detecting means for detecting the position of a speaker", "multiplexing means for multiplexing speaker position information and voice information", and "multiplexer. A main feature is that it has an "information separating means for separating speaker position information and voice information from a signal", and a "speaker position reproducing means for controlling a reproduction position of voice information based on the speaker position information". To do.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) FIG. 1 shows the configuration of the first embodiment of the present invention. 1 is a microphone, 2 is a speaker position data detection circuit that detects the position of the speaker when there is a voice input to the microphone, 3 is a voice codec (encoder) that converts an analog voice signal into a digital signal, and 4 is a digital Speaker position information multiplexing circuit for multiplexing the voice signal and the speaker position information, 5 is INS
A line interface circuit such as a net, 6 is a speaker position information separating circuit for separating a voice signal and speaker position information from a received signal, 7 is a voice codec (decoder) for converting a digital voice signal into an analog signal, and 8 is A speaker position reproducing circuit for switching and reproducing an analog voice signal to a corresponding speaker according to speaker position information, a speaker 9 and a control circuit 10 for controlling the entire circuit.

Hereinafter, the operation of the present embodiment (claims 1 and 4)
Will be described. Operation on the transmitting side When a voice is input to the microphone 1, the speaker position data detection circuit 2 detects the speaker position. The detected speaker position data * 1 is multiplexed with the voice data * 2 converted into a digital signal by the voice codec (encoder) 3 by the speaker position information multiplexing circuit 4 and transmitted to the line via the line interface circuit 5. .

FIG. 1 shows a method of multiplexing voice data * 2 and speaker position data * 1 in the speaker position information multiplexing circuit 4.
3 will be described. In the INS net, a telephone voice signal is sampled at 8 kHz, encoded with quantized 8 bits, and communicated with a transmission capacity of 64 kb / s. At this time, the quantization of 8 bits is set as one frame, and 8 kHz from the network.
The frame synchronization signal is transmitted to each terminal to establish frame synchronization between the transmission side and the reception side. In the present invention, it is considered that the simplest method is to use the frame synchronization of this network even when the speaker position data is interrupted in the voice data. FIG. 13 shows an example in which 1 frame is assigned voice data: 7 bits and speaker position data: 1 bit, and FIG. 14 is an example in which 1 frame is assigned voice data: 6 bits, speaker position data: 2 bits. There is (the S / N of the voice quality deteriorates by about 6 dB each time the quantized bit of the voice decreases by 1 bit). 7kH
z If you want to use high quality voice, CCITT G72
2, G725 has already standardized the method for multiplexing high-quality voice and data by the allocation shown in FIGS. 13 and 14. Therefore, the speaker position data * 1 is transmitted using the recommended data channel. Is good. Operation on the receiving side When a signal is received through the line interface circuit 5, the speaker position information separating circuit 6 separates the speaker position data # 1 and the voice data # 2. In the speaker position reproduction circuit 8, the reproduction level of the audio signal converted into the analog signal by the audio codec (decoder) 7 in each speaker 9 is calculated from the speaker position data # 1 and output from the speaker 9.

As described above, in this configuration, 1CH
The voice signal and the speaker position data are multiplexed on the transmission line of (1), and the level of the speaker for transmitting the voice signal is determined based on the speaker position data # 1 received on the receiving side. Therefore, the audio signal transmitted through the transmission path is 1CH (same as the conventional one),
The sound field control circuit (echo canceller, echo subdresser) for suppressing howling is similar to the conventional (monaural type) because there is no increase in the sneak path of the sound between the speaker and microphone due to the multi-channel transmission of the audio signal. There is a merit that can be configured with.

(2) FIG. 2 shows the configuration of the second embodiment of the present invention. Reference numeral 11 denotes a speaker position determination circuit that analyzes differences in time waveforms and frequency spectra of a plurality of microphone input signals to identify a speaker and determine the position of the speaker. Other numbers are the same as those in FIG. A processing example 1 of the plural microphone input analysis / speaker position determination circuit 11 and the speaker position reproducing circuit is shown in FIG. 6, a processing example 2 is shown in FIG. 7, and a processing example 3 is shown in FIG.

Hereinafter, the operation of this embodiment (claims 2 and 4).
Will be described. i) FIG. 6 is an example of a configuration in which a dedicated microphone is used for each conference participant and a dedicated speaker is used for each conference participant on the communication partner side. On the transmitting side, by comparing the levels of the microphones, only the signal from the microphone with the maximum input is switched, and the signal is transmitted as a voice signal and the position of the microphone with the maximum input is transmitted as speaker position data. The receiving side switches the speaker based on the received speaker position data and outputs a received voice signal.

Ii) FIG. 7 shows a configuration example in which the number of microphones and the number of speakers are two. On the transmitting side, the signals of the two microphones are mixed and transmitted as an audio signal,
The level ratio of the two microphones is calculated, and the level ratio data is transmitted as speaker position data. The receiving side controls the speaker output levels of the two speakers based on the received level ratio data, and outputs the received audio signal.

Iii) In FIG. 8, the configuration of the transmitting side is the same as that of FIG. 7, but the receiving side has three or more speakers, and the speakers are switched based on the received level ratio data, and the received voice is received. Output a signal. As described above, in this configuration, the speaker position data detection circuit is performed by comparing the input levels of the respective microphones, so that there is an advantage that it can be realized with a simple device configuration.

(3) FIG. 3 shows the configuration of the third embodiment of the present invention. Reference numeral 12 is a speaker detection circuit for identifying the presence or absence of a speaker and the speaker based on the characteristics of the audio signal. Reference numeral 13 is a conference participant (person) such as infrared (image), light, ultrasonic wave, or pressure sensor. A sensor, 14 is an presence / absence position detection circuit that detects the number of conference participants and the positions of individuals based on the information from the sensor, and 15 is a speaker position based on the speaker detection information and the presence / absence position detection information. This is a speaker position determination circuit for determining. Other numbers are the same as those in FIG.

FIG. 10 shows a processing example of the speaker detection circuit, presence / absence position detection circuit, and speaker position determination circuit. The operation (claims 3 and 4) of this embodiment will be described below. FIG.
The configuration on the transmitting side is an example in which one microphone and the presence / absence sensor are used, and the configuration on the receiving side is the same as in FIGS. On the transmitting side, the presence / absence sensor is composed of, for example, an infrared camera, and the presence / absence position detection circuit can detect the number of persons and each position in the detection area of this camera. Further, the speaker detection circuit extracts an individual characteristic parameter (pitch frequency or the like) from a voice signal input from one microphone, and determines who the current speaker is (speaker determination). The speaker position determination circuit recognizes the current position of each participant from the history of both information (presence / absence position information and speaker information), and determines the position of the speaker who just uttered from this history information. And output.

As described above, this configuration has the advantages that the position of the participant can be accurately grasped by the presence / absence sensor and that the configuration can be made even if there are no microphones.
Further, even when a plurality of speakers utter simultaneously, it is possible to detect the simultaneous utterance state of a plurality of speakers by analyzing the characteristic parameter of the voice signal in the speaker detection circuit. By transmitting the position information of a person with a large volume, the receiving side can control the sound image localization of the maximum-level speaker with priority, without the playback position of the speakers being mistakenly reproduced when multiple speakers are simultaneously speaking. There are merits.

(4) FIG. 11 shows a processing example of the speaker position reproducing circuit in the third embodiment of the present invention. The configuration of the embodiment is
It is the same as FIGS. The operation (claim 5) of this embodiment will be described below. FIG. 11 shows an example of processing for controlling the speaker reproduction level according to the current position on the listener (self) side in the processing example of FIG. In the case of localizing in the center, the position detection circuit detects that the listener D (self) is present in front of the speaker, and the sound image of the other speaker is detected by the speaker D at the position of the listener D (self). The volume of each speaker is controlled so that it is localized in the center.

As described above, in this configuration, the speaker position reproducing circuit is automatically controlled according to the position on the listener (self) side, so that the sound image that does not depend on the listener's position can be obtained with a small number of speakers. There is a merit that localization can be realized. (5) FIG. 4 shows the configuration of the fourth embodiment of the present invention. 16
Is a speaker state detection circuit that determines whether or not a plurality of speakers are speaking at the same time by extracting individual characteristic parameters (pitch frequency, etc.) from the voice signal input from the microphone,
Reference numeral 17 is a speaker state information multiplexing circuit for multiplexing the speaker state information and voice information, 18 is a speaker state information separating circuit for separating the speaker state information and voice information from the received signal, 19
When it detects that the received voice information is a mixed voice of multiple speakers from the speaker state information, it analyzes the mixed voice signal spectrum and synthesizes only the spectrum that matches the characteristic parameters (pitch frequency etc.) of each individual. by doing,
This is a speaker mixed voice separation circuit for separating the voice signals of individual speakers.

FIG. 9 shows an example of processing of the speaker mixed voice separation circuit. The operation (claim 6) of the present embodiment will be described below. Operation on Transmission Side As shown in FIG. 9, let us consider a case where three persons A, B, and C speak at the same time and two microphones are used. As the audio information, a synthetic signal of two microphones is output. Further, the positions of the A, B, and C speakers are detected from the time waveforms and frequency spectrum shifts (difference information) input to the two microphones. Also, individual characteristic parameters (pitch frequency, etc.) are extracted from the audio signal input from each microphone, and A,
It is detected that the B and C speakers are simultaneously speaking. These pieces of information are multiplexed and transmitted to the line. Operation on the receiving side The received signal is separated into voice (mixed state), speaker state information (whether or not simultaneous utterance is made, characteristic parameters of each speaker), and speaker position information. When the simultaneous speech state is detected, the mixed speech signal is spectrally analyzed, and the individual characteristic parameters are used to synthesize only the spectrum that matches the individual characteristic parameters (pitch frequency, etc.). Separate into the person's voice signal. Here, the characteristic parameter of each speaker is described as being transmitted, but a method of analyzing and extracting the received voice information is also conceivable. Next, the speaker position reproducing circuit is controlled so that the voice localization of each separated speaker is performed according to the speaker position information.

As described above, the present configuration has the advantage that even if a plurality of speakers speak at the same time, the voices of the speakers are separated and localized even though the channel is a one-channel transmission path. It should be noted that the present invention has been described with a configuration using two microphones in order to detect the position information of each speaker.
A configuration with one microphone and a sensor as shown in FIG. 3 is also possible. Further, when the mixed voice is separated without transmitting the speaker position and the separated voice is reproduced by each speaker, it may be possible to configure one microphone and a plurality of speakers as shown in FIG.

(6) FIG. 5 shows the configuration of the fifth embodiment of the present invention. Reference numeral 20 is an operation key capable of inputting remote control information (microphone input switching and signal level control) of the microphone input of the other party, 21 is a multiplexing circuit for this microphone input remote control information and voice information, and 22 is its separation. A circuit, 23 is a microphone input control circuit for controlling microphone input switching and signal level based on this microphone input remote control information, and 24 is an amplifier for reproducing a speaker. FIG. 12 shows a processing example of the microphone input remote control key and the microphone input control circuit.

The operation of this embodiment will be described below. Operation on the receiving side When control data * 4 such as multiple microphone input levels on the other side is input by the microphone input remote control key 20, the microphone input remote control data * 4 is converted into a digital signal by an audio codec (encoder). The voice data * 2 thus obtained is multiplexed with the microphone remote control information multiplexing circuit 21 and transmitted to the line via the line interface circuit 5. Operation on the transmitting side When a signal is received via the line interface circuit 5, the microphone remote control information separating circuit 22 separates it into microphone input remote control data # 4 and voice data # 2. The microphone input control circuit 23 controls microphone switching and level according to the microphone input remote control data # 4.

As described above, in this configuration, since the listening side can control the input level and the like of the microphone on the transmitting side, the utterance level of the other speaker changes or the position of the other speaker fluctuates. Even so, there is a merit that you can freely adjust it so that it is easy for the listener to hear.

[0025]

As described above, according to the present invention, since the sound image localization of the speaker can be performed by the one-channel transmission path, a voice conference apparatus having the following advantages and high speaker identification can be easily realized. be able to. (1) Since there is only one transmission line, there is no increase in call charges. (2) Although multiple speakers are used, all speakers are not always in use, but switched and used. When viewed in time units, only one speaker is used. Therefore, howling suppression between speakers and microphones is suppressed. The sound field control circuit (echo canceller, echo subdresser) for this can be realized with a device configuration that is not much different from the conventional one. (3) Since the playback side can make one speaker correspond to one speaker, in that case, the playback side has the same speaker localization regardless of where it is heard. There is no problem of restriction of participation place (it cannot be localized unless listening in the center of the left and right speakers) which is a problem during stereo playback.

Further, in the present invention, the information for controlling the level of the microphone on the transmitting side can be multiplexed with the voice information and transmitted from the receiving side, so that the receiving side can freely adjust it so that it can be heard easily. It is possible to easily realize a voice conference device with good performance and ease of use.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment corresponding to claims 1, 4, and 5 of the present invention.

FIG. 2 is a block diagram showing an embodiment corresponding to claims 2, 4, and 5 of the present invention.

FIG. 3 is a block diagram showing an embodiment corresponding to claims 3, 4, and 5 of the present invention.

FIG. 4 is a block diagram showing an embodiment corresponding to claim 6 of the present invention.

FIG. 5 is a block diagram showing an embodiment corresponding to claim 7 of the present invention.

FIG. 6 is a diagram for explaining a processing example 1 of the plural microphone input analysis and speaker position determination circuit and the speaker position reproduction circuit according to claims 2 and 4 of the present invention.

FIG. 7 is a diagram for explaining processing example 2 of the plural microphone input analysis and speaker position determination circuit and the speaker position reproduction circuit according to claims 2 and 4 of the present invention.

FIG. 8 is a diagram for explaining Processing Example 3 of the plural microphone input analysis and speaker position determination circuit and the speaker position reproduction circuit according to claims 2 and 4 of the present invention.

FIG. 9 is a diagram for explaining a processing example of a plural microphone input analysis and speaker position determination circuit and a speaker mixed voice separation circuit according to claims 2, 4, and 6 of the present invention.

FIG. 10 is a diagram for explaining a processing example of the speaker detection circuit, presence / absence position detection circuit, and speaker position determination circuit according to claim 3 of the present invention.

FIG. 11 is a diagram for explaining a processing example of the speaker position reproducing circuit according to claim 5 of the present invention.

FIG. 12 is a diagram for explaining a processing example of a microphone input remote control key and a microphone input control circuit according to claim 7 of the present invention.

FIG. 13 is a diagram for explaining a method of multiplexing voice data and speaker position data used in the present invention.

FIG. 14 is a view similar to FIG. 13;

[Explanation of symbols]

 1 Microphone 2 Speaker position detection circuit 3 Voice codec (encoder) 4 Speaker position information multiplexing circuit 5 Line interface circuit 6 Speaker position information separation circuit 7 Voice codec (decoder) 8 Speaker position reproduction circuit 9 Speaker 10 Control circuit

Claims (7)

[Claims] 1. A speaker position detecting means for detecting a position of a speaker on a transmitting side, and a talk detected by the speaker position detecting means in a voice conference device capable of communicating with a remote party by a microphone and a speaker. Information separation for separating the speaker position information and the voice information from the signal multiplexed by the above-mentioned multiplexing means on the receiving side is provided with multiplexing means for multiplexing the speaker position information and the voice information input from the microphone. And a speaker position reproducing unit for controlling a reproduction position of voice information based on the speaker position information separated by the information separating unit. 2. The voice conference apparatus according to claim 1, wherein the speaker position detecting means has a plurality of microphones, a time waveform and a frequency spectrum of an input signal of each microphone, and these signals between the microphones. From the difference, the voice conference call apparatus is characterized by comprising a speaker position determination unit that identifies a speaker and determines the position of the speaker. 3. The voice conference apparatus according to claim 1, wherein the speaker position detecting means identifies presence / absence position sensors for detecting the number of persons and positions of each individual, and specifies presence or absence of utterance and a speaker. A voice conference device comprising a speaker detection unit, and a speaker position determination unit that determines the speaker position based on the presence / absence position sensor and detection information of the speaker detection unit. . 4. The voice conference call device according to claim 1, wherein the speaker position reproducing means provided on the receiving side is associated with a speaker position to switch speakers, or a plurality of speakers are provided. A voice teleconference device comprising a speaker control unit for controlling the level of voice information given to the device. 5. The voice conference apparatus according to claim 4, wherein the speaker position reproducing means is provided so that an optimum speaker sound image is obtained at the listener position detected by the speaker position detecting means. A voice conference device comprising a speaker control unit for controlling the levels of a plurality of speakers. 6. The voice conference call apparatus according to any one of claims 1 to 5, wherein a speaker-mixed voice separating unit is provided on the receiving side, and a plurality of speakers simultaneously speak from the information separating unit. When the information to the effect is received, the speaker mixed voice separation means is activated, and the mixed voices of the plurality of speakers output from the information separation means are converted into individual voice signals of the plurality of speakers. A voice teleconference device which is separated and controls the reproduction position of each speaker's voice based on the speaker position information of each speaker. 7. A voice conference call device capable of making a call with a remote party by a microphone and a speaker, and a microphone input remote control information input means capable of inputting remote control information of a microphone input of the other party to the transmitting side, and the microphone. Provided is a multiplexing means for multiplexing the remote control information of the microphone input inputted by the input remote control information input means and the voice information, and the microphone input remote control information from the signal multiplexed by the multiplexing means on the receiving side. An information separating means for separating voice information and a microphone input controlling means for controlling switching of a microphone input and an input signal level based on the microphone input remote control information separated by the information separating means are provided. Audio conference device.