JPH04369152A - Speech system for conference telephone service - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a system for selectively transmitting monaural audio/stereo playback audio to both terminals in a conference telephone service that accommodates a mixture of existing monaural telephone terminals and ISDN terminals capable of receiving left and right two-channel audio. This is related to the call method of the conference telephone service.

0002

[Prior Art] Conventional conference telephone service call methods include Japanese Patent Application Laid-Open No. 60-38961 and Japanese Patent Application Laid-Open No. 59-1
An example of this is the conference telephone service call method described in Japanese Patent No. 52770. In these conventional technologies, the terminal has one pair of transmitting and receiving terminals, one-ear listening, and one ear for each subscriber.
Because the monaural audio of the line was added together using a conference telephone device and the monaural added audio was heard by the subscribers, there was no sense of direction and the conference lacked a sense of realism. Furthermore, as the number of additions increases, the audio quality will deteriorate. Also,
In conferences using telephone terminals, there is no calling system for conference telephone services that coexists with existing one-way telephones and telephone terminals capable of receiving left and right two-channel audio.

0003

[Problems to be Solved by the Invention] As described above, the above-mentioned prior art has the problem that it is not possible to provide an additive voice reception service with a difference in direction between the left and right channels.

[0004] Therefore, in order to give a sense of realism to a conference, it is conceivable to install a plurality of speakers and microphones in a multi-point conference room connected by communication lines and to reproduce a plurality of channels. However, in this case, it is possible to provide a realistic conference call due to the binaural effect, but this cannot be achieved by using common and economical terminals such as telephones, and speakers,
In addition to microphones, it is also necessary to prepare a conference room, which creates a problem in that the number of subscribers who can install it is limited.

[0005] In addition, existing conference services do not take into consideration the mixed accommodation of existing one-way telephones and telephone terminals that can receive left and right two-channel audio, so it is difficult to shift from the existing one to two-channel audio reception for the left and right ears. There were some problems, such as not being able to do it.

An object of the present invention is to provide a realistic conference call service with an economical configuration and simple settings, and to provide a telephone conference call service that is easy to use, regardless of the existing two-channel receiving terminal for left and right ears. The goal is to make it possible.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the call system of the conference telephone service of the present invention constantly monitors the call volume of a conference call between three or more subscribers, In addition to determining whether there is a sound, the number of subscribers to be added is determined based on the information on the number of subscribers participating in the conference, and the determined number of subscribers are selected in order of volume from highest to lowest at regular intervals. In the call method of the conference telephone service, in which each subscriber receives the call after adding up the voice of Based on the left and right ear audio arrival time difference information for each participating subscriber that can be heard in both ears of each participating subscriber determined by the calculation method, the subscriber's voice input on one line (channel) is ), and a delay circuit that adds a time difference between the binaural audio signals based on the left and right audio arrival time difference information, and an addition circuit for left and right ears that adds the signals to each ear for each subscriber. (Single line) We decided to divide the audio into two lines, left and right, and provide it to subscribers as additional conference audio with a sense of direction due to the time difference.

[0008]

[Effect] The received audio of the 2nd line (channel) is made to have a sense of direction using the left and right ear audio arrival time difference information calculated from the conference seat image set from the upper level using a certain calculation method for the outgoing audio of the 1st line (channel). Since we have installed a delay circuit that converts the sound into a delay circuit and an adder circuit that adds the sound for both left and right ears to the subscriber, we can provide the added sound for both ears to the subscriber, and the conference sound that arrives from a direction close to the actual meeting can be Can be distinguished.

[0009] Furthermore, if the subscriber uses an existing one-telephone telephone, the sound of the two lines (channels) for left and right ears are simply added together, the level is attenuated, and the control is performed to transmit the sound on one line (channel). By doing so, it is possible to perform additional audio transmission according to the type of subscriber terminal.

[0010]Furthermore, the host center sets an image of the conference position based on the number of participating subscribers specified by the organizer, the shape of the conference table, etc. By calculating ear audio arrival time difference information and notifying it from the center to the control circuit of the conference telephone device at the start of a conference, an economical and easy-to-operate conference telephone service can be realized, as well as flexibility such as the ability to select any conference configuration. Can be secured.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to FIGS. 1 to 3.

The first and second embodiments will be explained with reference to FIG. FIG. 1 shows a block diagram illustrating one embodiment of the invention. FIG. 2 shows an image of conference seat positions in one embodiment of the present invention. FIG. 3 shows a principle diagram of the binaural sound arrival time difference in an embodiment of the present invention. In Figure 1, 1 is for left and right ears 2
A telephone terminal capable of receiving channel voice, 2 an existing transmitting/receiving one-to-one telephone terminal, 3 a known digital exchange, 4 a conference telephone device, 5 a communication path interface facing the multiplexed communication path of the exchange, 6 7 is an audio level detection circuit that constantly monitors the digitized voice level of each subscriber for each subscriber line (channel or highway time slot) and detects the level. The audio signal (1 line) is separated into two lines (channels) for the left and right ears, and is sent to each subscriber line (channel) designated by the upper center.
8 is a delay circuit that delays the audio signal on the ear side, which has a slower arrival time, from the audio signal on the other ear based on the left and right ear audio arrival time difference information for each line (channel). 9 is an addition circuit for the right ear that adds the audio from other subscribers, 9 is an addition circuit for the left ear that adds the audio from other subscribers that is received by the left ear, and 10 is the number of conference participants sent from the center device. Receives left and right ear audio arrival time difference information for each channel, and based on that information, the delay circuit in the conference device and the control circuit that controls audio addition, HA, HB~
The HN is a hybrid system that converts the transmitted and received voice of a telephone from four lines to two lines.

When the conference time comes, the number of conference participants preset by the organizer, subscriber accommodation lines, and conference seat image correspondence information are set in the control circuit 10 of the conference telephone device 4 from the center. In the control circuit, for example, NO.
One line is conference seat A, No. 2nd line is conference seat B..., NO.
The correspondence between lines and positions is set from the correspondence information in which line n is designated as conference seat F, etc., and then the correspondence between lines and positions is set. A table of left and right ear audio arrival time difference information (a value calculated from Federson's actual measurement results) is created based on the fixedly associated azimuth angles of B,...F with respect to the subscriber conference seat position A of one line.
No. Associate with 1 line. For B, A,...F, and other conference seat positions, left and right ear audio arrival time difference information tables from other participant positions are similarly created and associated with each line. In this state, from the telephone terminal 1 capable of receiving two-channel audio for the left and right ears, the NO. After monaural audio using one line passes through the exchange 3, it is digitized into a multiplexed highway and input to the communication path interface 5.

When the sound of each line (channel) is transmitted from the communication path interface 5 to the delay circuit 7, the sound level of each line (channel) is monitored by the sound level detection circuit 6 and notified to the control circuit 10 as level information. In the control circuit 10,
In order to determine the predetermined number of additional participants based on the number of participants, additional lines (conference seat positions) are selected in descending order of level.

On the other hand, monaural audio from each line input to the delay circuit 7 is branched into two lines for the left and right ears, and then sent to the control circuit 1.
Based on the left and right ear audio arrival time difference information associated with each line correspondence in 0, the audio signal of the line corresponding to the ear that arrives later is delayed, and the left ear adding circuit 9 and the right ear Input to adder circuit 8. Both adder circuits have adder circuits (buffers) corresponding to subscriber lines, and buffer the delay-controlled audio information from other participating subscribers. When this buffered audio is added to each line for both ears, only the lines (conference seat positions) selected for addition are added by the control circuit 10, and after the level is attenuated, each subscriber receives the voice. Send to line. The reception line is two lines (channels) for both left and right ears, corresponding to each subscriber, and is multiplexed and transmitted for each left and right subscriber. This binaural addition audio signal is demultiplexed into two binaural lines for each subscriber by the exchange 3 via the communication path interface 5, and is sent to all participants participating in the conference. The conference participant listens with both ears to the added audio for the left and right ears with a time difference of the selected subscriber from the telephone terminal 1 capable of receiving the left and right audio channels.

A second embodiment will be explained with reference to FIG. 1 to 10 in FIG. 1 have already been explained in the first embodiment, and will therefore be omitted. 11 multiplexes subscriber lines for each left and right ear from the left and right adder circuits, adds the two channels of added audio for the left and right ears sent out, and attenuates the level to create a receiving voice that is paired with the transmitted voice. This is a left and right audio channel adding circuit 11 that sends out to one line.

[0017] During a conference call, NO. If the terminal connected to the n line is an existing transmitting/receiving one-to-one telephone terminal 2, at the start of the conference, the center will send No. The terminal for the n line is designated as the existing transmitting/receiving 1-to-face telephone terminal 2 by the conference telephone device 4.
control circuit 10. As the principle was explained in the first embodiment, NO. The received voice to the n line is sent out from the left and right ear adder circuits through two lines (channels), but the control circuit 1
By specifying 0, the left and right audio channel adder circuit 11 selects NO.
The audio of the two channels for the left and right ears of the n line is added together, the level is attenuated, and the receiving line 1 is paired with the sending line.
Send to line (channel). A no-call signal is sent to the other receiving line (channel).

[0018] This voice passes through the communication path interface 5 and is sent to the exchange 3 as NO. N lines, and is heard by participating subscribers as quasi-monaural conference addition audio from the handsets of existing one-to-one telephone terminals. A third embodiment will be explained with reference to FIG. 1, FIG. 2, and FIG. 3. As explained in the first embodiment, the binaural audio arrival time difference information for each channel is determined by the control circuit in the conference device based on a fixed image of conference seats to prevent the circuit from becoming complicated and large. It had binaural audio arrival time difference information for the maximum value of the line. In other words, each line (participant) other lines (
It has all the arrival time difference values of the binaural sounds heard from other participants), but the image of the conference seats is one type, and the only variable factor is whether there are many or few participants. In the third embodiment, a method is adopted in which the center device calculates binaural audio arrival time difference information from an arbitrary conference position (seat) image and sends it to the conference telephone device.

First of all, if the conference organizer sets the conference seat position image (number of people, conference table configuration) in advance from his own phone, the contents will be registered in the center device.In FIG. 2, the conference table is rectangular. An example of the location of conference seats for six participants is shown below. Note that the number of people and the configuration of the conference can be set arbitrarily within the number of terminals (maximum number of channels) accommodated by the conference telephone device. A conference seat image can be arbitrarily set based on a combination of the type of conference table (round table, square table, rectangular table) and the number of participants.

When a conference is held, necessary settings are transferred from the center to the control circuit 10 of the conference telephone device 4. The transfer information includes the number of people (including TEL NO.) and time difference information between the left and right channel audio of each terminal, which will be described later.

[0021] Each conference participant's line is connected to a physical terminal (channel) of the conference telephone device. In the example of FIG. 2, organizer A is the No. Connect to one line (channel), and the same applies to B to F below.

With this connection, the telephone sounds from each terminal (A to F) are input in monaural, so the sounds have no sense of direction. Therefore, in order to give a sense of direction, this monaural audio is divided into two channels corresponding to the left and right ears, and a time difference is added to create a sense of direction.

[0023] This principle is based on the “New Edition” published by the Institute of Electronics and Communication Engineers.
This is an application of the following principles described in "Hearing and Speech: Supervised by Tanetoshi Miura, Doctor of Engineering."

[0024] The propagation path of sound heard by both ears differs depending on the direction. The distance difference d can be approximated from FIG. 3 as shown in equation (1).

d=r(θ+Sinθ)
(1) By applying the above principle, the information on the time difference (t) in which audio reaches both ears of each participant (channel) can be set as follows.

t[s]=r(θ+Sinθ)/340
...(2) r: Head radius = 0.085 m θ: Speaker's azimuth angle from the front of the listener Based on Figure 2, the difference in time between the arrival of voices from other participants to both ears of organizer A is found. As shown in Table 1.

[0027] The audio arrival time difference is similarly determined for participants B to F, and this time difference information is transferred from the center to the control circuit 10 of the conference telephone device 4 at the time of service start, so that the time difference information can be calculated for each conference service. The time difference can be set arbitrarily.

[0028]

[Effects of the Invention] Since the present invention is constructed as described above, it produces the effects as described below. Conference participants can receive 1 channel of monaural audio and 2 channels of audio added for the left and right ears using a simple telephone terminal with 2 channels that allows listening to both ears.
Listen to conference audio that provides a sense of economic direction and improve the level of communication. In addition, if the terminal is a one-way telephone terminal for transmitting and receiving, the two-channel audio for both ears can be added together and sent as one channel of quasi-monaural audio, so it is possible to combine the two-channel audio for both ears and send it out as one channel quasi-monaural audio. It is possible to hold a conference that accommodates a mixture of transmitting and receiving one-to-one telephone terminals. Furthermore,
The organizer simply specifies the number of participating subscribers and the shape of the conference table, and the center sets an arbitrary conference seat image based on the organizer's specifications, and then sends each participating subscriber to the left and right ears from other participating subscribers. By providing a means to calculate the audio arrival time difference information and send it to the control circuit of the conference device, it is possible to realize an economical and easy-to-operate conference telephone service, and also to be able to select any conference configuration, providing flexibility. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention;

[Figure 2]
Conference seat position image in an embodiment of the present invention,

FIG. 3 is a diagram of the principle of binaural sound arrival time difference in an embodiment of the present invention;

[Explanation of symbols]

1...Telephone terminal capable of receiving two channels of audio for the left and right ears 2...Existing one-to-one transmitting/receiving telephone terminal 3...Digital exchange 4...Conference telephone device 5...Call path interface 6...Audio level detection circuit 7...Delay circuit 8...Right Ear addition circuit 9...Left ear addition circuit 10...Control circuit 11...Right and left audio channel addition circuit

Claims (3)

[Claims] Claim 1: Constantly monitor the call volume of a conference call between three or more subscribers, determine whether each subscriber is silent or active, and add the number of subscribers based on information on the number of subscribers participating in the conference. A conference telephone service in which the determined number of subscribers is selected in descending order of volume at regular intervals, their voices are added up, and each subscriber receives the call, excluding the own voice. In the call system, each participating subscriber can hear each participating subscriber's voice in both ears, which is determined by a certain calculation method from the subscriber accommodating line number set in advance by the organizer and the conference seat image correspondence information of the participants. The subscriber voice input through one line (channel) is separated into two lines (channels) for both left and right ears based on the left and right ear audio arrival time difference information, and the time difference is added to the binaural audio signal based on the left and right ear audio arrival time difference information. A delay circuit for each subscriber and an addition circuit for left and right ears for each subscriber are installed to add the monaural (1
A conference telephone service call system characterized by dividing the audio into two lines, left and right, and providing the subscriber with additional conference audio with a sense of direction due to the time difference. 2. In the conference telephone service call system according to claim 1, two lines (channels) for the left and right ears to be sent to the subscriber are simply added together, the level is attenuated, and one line (channel) is converted into a quasi-monaural signal. The left and right audio channel adding circuits and control circuits that transmit data on the left and right audio channels are equipped with a means to control the operation and stop of the circuit functions based on the specification of participating subscriber terminals from the center equipment, so that the existing telephone equipment and left and right ear A conference telephone service calling system is characterized in that it is possible to select and provide one line of monaural audio and two lines of left and right binaural audio with a sense of direction to each terminal capable of receiving two-channel audio. [Claim 3] In the call system of the conference telephone service according to claim 1, the number of participating subscribers, TELN
Means for creating a conference position image from a combination of conference table configurations such as round tables, square tables, rectangular tables, etc. and participating subscribers to a center device that instructs O etc. means for determining the positional angle of the participant, and setting information on the time difference between the left and right ears of audio from other participating subscribers that reaches both ears of each participating subscriber based on a certain calculation formula, and the information at the start of the conference. A conference characterized in that an arbitrary conference format can be selected by providing a means for transmitting and setting the information to a control circuit of a conference telephone device, and making simple settings based on the organizer's designation of the number of participating subscribers, the shape of the conference table, etc. Telephone service call method.