JP2714708B2 - Conference call terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used for a conference call device. In particular, the present invention relates to a talker terminal that is connected to each other via a voice line for a conference call and generates a sound image with a headphone-type binaural receiver. More specifically, the present invention relates to sound image position recognition for identifying a transmission source from a plurality of callers at individual caller terminals.

The present invention relates to a conference call terminal device capable of reproducing a sound image at a different position for each talker with a binaural receiver for a plurality of talkers. This facilitates person recognition.

[Conventional technology]

In the teleconference call system, it is desired to generate a sound image in a different place for each caller in order to identify the caller who is transmitting and to obtain the atmosphere of a general meeting where participants gather. .

As such a conference call method, a method of connecting a plurality of grounds and generating a sound image for each ground is known, for example, Shimada,
Suzuki, "Ground discrimination sound image generation method for multi-site audio conference communication system", IEICE Journal, Vol.9, No.9, 1 (1
September 987). The contents of this paper will be described with reference to FIGS. 4 and 5 and a table.

In the teleconferencing communication system shown in the above paper,
The terminal that has become the sender simultaneously transmits, together with the voice, the sender control information indicating the sender. A code format as shown in the table is used for the transmission source control information.
That is, the bit corresponding to the transmission source ground number is “1”.
The other uses a signal of "0". This source control information is
The voice is transmitted to a plurality of destinations via the node device together with the voice. On the receiving side, according to the content of the source control information,
The sound is generated at a predetermined sound image position.

FIG. 4 shows an example of a 6-to-ground connection, and FIG.
Shows a method of generating a sound image in.

Here, it is assumed that caller A is speaking as a transmitter. At this time, the voice signal and the transmission source control information “100000” are simultaneously transmitted from the talker A to the node device 40.
The node device 40 transmits the voice signal from the caller A and the transmission source control information “100000” to the callers B to F in a broadcast manner.

On the listening side of the caller B, the out-of-head sound image localization is determined in accordance with the caller number excluding his own caller number, and the sound image of the voice information is generated outside the head according to the transmission source control information signal.
In this way, the caller can be easily recognized by confirming the occurrence of the current caller from the predetermined sound image localization.

For details of sound image localization by binaural receivers, refer to Japanese Patent Application No. 1-59942, "Out-of-head localization headset communication system".
Is shown in In this earlier application, the source signal and the audio signal are transmitted simultaneously in the same time slot,
Since a sound image is generated at a position designated in advance, it is possible to easily determine who the voice is.

[Problems to be solved by the invention]

However, in the above-described conventional technology, the sound image generation position corresponding to the transmission source signal is forcibly determined in advance, so that the voice of the person to be noticed is generated at the center for each conference call, or the listener's voice is generated. The sound image could not be generated at the desired position.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a conference call terminal device capable of changing a setting of a sound image generation position by a binaural receiver according to a request of a listener.

[Means for solving the problem]

The conference call terminal device according to the present invention is a setting change input means which can be operated by a listener to change a setting of a sound image position for a caller generated by two electroacoustic conversion means corresponding to both ears of a person. And means for converting a control signal for localizing the received sound image into a control signal corresponding to the setting change input to the setting change input means.

If the setting is not changed by the setting changing means, a sound image is generated at a preset position according to the received control information. Desirably, the conversion means is configured to exchange the sound image positions for the two callers.

[Action]

In the conference call terminal device receiving the audio signal from the other conference call terminal device, according to the received control information, a binaural receiver provided with two electroacoustic conversion means corresponding to the binaural of the person, A sound image having a different position is generated for each conference call terminal device of the other party. At this time, the sound image position can be freely changed by the listener's manual operation. This change can be made for each conference call or during a conference call. Thereby, for example, the generation position of the person of interest can be moved to the position desired by the listener.

〔Example〕

FIG. 1 is a block diagram of a conference call terminal according to an embodiment of the present invention.

The apparatus of this embodiment includes a linear encoding circuit 2 and a digital / analog circuit as sound image generating means for generating a sound image corresponding to a sound signal received from a voice line for a conference call by two electroacoustic conversion means corresponding to both ears of a person. Transducer 7, low-pass filter 8r, 8l, amplifier 9r, 9l and binaural receiver 10
And sound image localization switching circuits 4, 6 and sound image localization means for localizing sound images generated by the sound image generation means to different positions for each other party in accordance with a control signal received together with an audio signal from an audio line. Information parameter multiplying circuits 5r and 5l are provided. The binaural receiver 10 includes two electroacoustic transducers 10r and 10l.

Here, the feature of the present embodiment is that a control panel 11 is further provided as a sound image localization means, and a control panel 11 is provided as means for changing the setting of the sound image position with respect to the other party by operation of the listener. The switching control circuit 3 is provided as means for converting control information.

The voice signal from the voice line and the control signal (transmitter control information) are separated by a signal separating circuit 1, and the voice signal is supplied to a linear encoding circuit 2 and the transmitter control information is supplied to a switching control circuit 3. Is done.

The linear encoding circuit 2 converts the encoded audio signal from the transmission path into a linear code. This is for digital operation.

The output of the linear encoding circuit 2 is supplied to the sound image localization information parameter multiplying circuits 5r and 5l via the sound image localization switching circuit 4. The sound image localization information parameter multiplying circuits 5r and 5l store parameters obtained by convolution of a head impulse response in an actual sound field and an inverse filter characteristic for correcting a receiver characteristic in a voice band, and store this parameter in a linear code. Convolution operation on the converted audio signal. This allows
A digital signal containing sound image localization information is obtained. This signal is passed through a digital-to-analog converter 7, low-pass filters 8r, 8l and amplifiers 9r, 9l to a binaural receiver.
Sent to 10.

The sound image localization switching circuits 4 and 6 are switched by the sound image generation control output information supplied from the switching control circuit 3. By this switching, the sound image localization information parameter multiplication circuits 5r, 5l
Can set the value of the parameter to be convolved with the audio signal, and can perform sound image localization of the analog signal supplied to the binaural receiver 10.

When changing the position where the sound image is generated, for example, when there is a request that the listener wants to change the position where the sound image is generated for a remarkable person's remark by listening to the sound of the transmission source, the sound is While listening, a push button on the control panel 11 provided corresponding to a desired sound image generation position is pressed. Information on the pressing of the push button is supplied to the switching control circuit 3 as sound image generation control input information. The switching control circuit 3 converts the transmission source control information according to the sound image generation control input information, and supplies it to the sound image localization switching circuits 4 and 6 as sound image generation control output information.

The code format shown in the table is suitable as the transmission source control information for n-to-ground or n-speaker identification, but a code having the opposite logic may be used. Since the signals of this code sequence are uncorrelated with each other, even if a plurality of speakers utter simultaneously, processing at the node device is possible. The same code sequence signal is used for the sound image generation control input information output from the control panel 11.

FIG. 2 is a block diagram showing details of the switching control circuit 3. As shown in FIG.

The switching control circuit 3 includes ON / OFF detectors 21 and 25, an address memory 22, an n × n-bit random access memory 23, an information output memory 24, a sequencer 26, an information input memory 27, and a switch 28.

The ON / OFF detector 21 detects whether or not the transmission source control information transmitted from any destination via the node device has been received, based on the presence or absence of the control input. When the transmission source control information is received, the information is stored in the address memory 22. When the transmission source control information has not been received,
It is assumed that no voice signal has been received, and in that state, the transmission source control information is awaited.

The transmission source control information stored in the address memory 22 corresponds to the address number of the random access memory 23,
The information content is stored in the information output memory 24.

The information stored in the information output memory 24 is sent to the sound image localization switching circuits 4 and 6 via the switch 28 as sound image generation control output information.

When the on / off detector 25 detects the sound image generation control input information from the control panel 11, it outputs the information as it is to the sound image localization switching circuits 4 and 6 via the switch 28, and the same information is stored in the information input memory. Store in 27.

The information content stored in the information input memory 27 is first written into the random access memory 23. This allows
The content of the address number specified by the transmission source control information is rewritten to the sound image generation control input information from the control panel 11.

Subsequently, the same information content is transferred from the information input memory 27 to the address memory 22, and the information stored at that time in the information output memory 24 is transferred to the information input memory 27, and written to the random access memory 23. Thereby, the information content of the address specified by the sound image generation control input information from the control panel 11 is rewritten to the content corresponding to the transmission source control information at that time.

In this way, by operating the control panel 11, the information contents of the random access memory 23 corresponding to the address numbers are exchanged with each other. For example, it is assumed that the information content corresponding to the address number "100000" is "100000" and the sound image generation control input information is "000100". At this time, the information content specified by the address number “100000” becomes “000100” and the information content specified by the address number “000100” becomes “100000” by the above-described operation.

Information transfer among the address memory 22, the random access memory 23, the information output memory 24, and the information input memory 27 is performed under the control of the sequencer 26. Sequencer 26
Starts the control operation by the detection output of the on / off detector 21 or 25. FIG. 3 shows the control flow of the sequencer 26.

〔The invention's effect〕

As described above, the conference call terminal device of the present invention includes:
The position of the sound image outside the head by the binaural receiver can be freely changed by the listener's manual operation. Also, at this time, not only a sound image is generated at the newly specified sound image position, but also by replacing the sound image generation control information with respect to the previous transmission source control information, a different voice is generated for each caller from next to next. The sound image position can be changed.

In the present invention, since the sound image position can be changed by a simple operation,
It is possible to maximize the attention of the listener to the caller who makes an important statement, and it is possible to further enhance the convenience of the conference call.

[Brief description of the drawings]

FIG. 1 is a block diagram of a conference call terminal according to an embodiment of the present invention. FIG. 2 is a block diagram of a switching control circuit. FIG. 3 is a diagram showing a flow of control of a switching control circuit by a sequencer. FIG. 4 is a block diagram showing a conventional multipoint audio conference communication system. FIG. 5 is a diagram showing a sound image generation method in a conventional example. 1 ... Signal separation circuit, 2 ... Linear encoding circuit, 3 ...
Switching control circuit, 4, 6 ... Sound image localization switching circuit, 5r, 5l ...
... Sound image localization information parameter multiplication circuit, 7 ... Digital-to-analog converter, 8r, 8l ... Low-pass filter, 9r,
9l …… Amplifier, 10… Binaural receiver, 10r, 10l …… Electro-acoustic transducer, 11 …… Control panel, 21/25 …… On / off detector, 22 …… Address memory, 23 …… Random access Memory, 24 ... Information output memory, 26 ... Sequencer, 27 ...
... Information input memory, 28 ... Switcher.

Claims (1)

(57) [Claims] 1. A sound image generating means for generating a sound image corresponding to a sound signal received from a voice line for a conference call by two electroacoustic conversion means corresponding to both ears of a person, and a sound image generated by the sound image generating means. And a sound image localization means for localizing each of the other parties in accordance with a control signal received together with a voice signal from the voice line.The sound image localization means sets a sound image position for the other party. Setting change input means that can be operated by the listener to change, and means for converting a control signal for localizing the received sound image into a control signal corresponding to the setting change input to the setting change input means; A conference call terminal device comprising: