JPH02217100A - Stereo sound receiving type head set - Google Patents

Abstract

PURPOSE:To attain stereophonic transmission with compact constitution and to improve the transmission quality of speech voice and ease of handling by devising the head set such that a voice signal of a talker is added to a signal subject to stereophonic reception when a voice level of the talker exceeds a prescribed value. CONSTITUTION:The stereophonic sound reception is implemented by using 2 sets of unidirectional microphone devices comprising microphones 2a, 2b, 3, a delay arithmetic circuit 4 and computing elements 5a, 5b and the environmental sound around a talker is sent to opposite speakers 6a, 6b. When a control means 7 decides it that the voice level received by the microphone 3 exceeds a prescribed value, a switch 8 normally opened is thrown to the make position, a voice signal from the microphone 3 is added to a voice signal from the microphones 2a, 2b by adders 9a, 9b respectively and sent to the opposite speakers 6a, 6b. Thus, stereophonic transmission is attained with compact constitution and the transmission quality of the voice of the talker and the ease of handling are improved.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a stereo sound-receiving headset that is used in conference systems such as video conferences and telephone audio conferences and is capable of stereophonic transmission. With the aim of making it possible to communicate with the user while also improving the transmission quality of voice calls and making it easier to use, the system is equipped with multiple sound receiving sections near the mouth of the caller to perform stereophonic sound reception, and to improve the voice level of the caller. When a predetermined value is exceeded, the voice signal of the caller is added to the stereophonically received signal.

[Industrial Application Field] The present invention relates to a stereo sound receiving headset that is used in conference systems such as video conferences and telephone audio conferences and is capable of stereophonic transmission.

In recent years, with the development of conferencing systems such as video conferencing and telephone audio conferencing, which allow participants to communicate with remote parties, the communication of sound is the same as if both parties were in the same meeting, in other words, each other's own presence. It is required to transmit the sound field as accurately as possible to the other party. In particular, when audio is stereophonically transmitted and reproduced along with surrounding environmental sounds, the other party's audio can be heard localized to one point in the expanded environmental sound, which improves the sense of presence and clarity, which is useful.

[Prior Art] Conventionally, conference systems such as video conferencing and telephone audio conferencing have used a tabletop or tie-pin type microphone installed in advance and a fixed speaker. Like the telephone, it receives monaural sound and transmits monaural audio to the other party.

[Problem to be solved by the invention] However, with the development of communication networks, it is necessary to improve the transmission quality of such conference systems. An effective means is to realize stereophonic transmission that transmits and reproduces signals.

In order to realize stereophonic transmission, it is possible to use conventional stereophonic microphones, but they are both large and have a large number of parts and are not suitable as communication terminals. Therefore, in the future, it is desired to provide a simpler device so that even a small number of people can use a conference system capable of stereophonic transmission more easily.

In addition, in order to realize stereophonic transmission, it is possible to construct a compact device by installing a stereophonic microphone that can accurately receive surrounding sounds near the mouth of the caller. Since the mouth is located in the blind spot direction of the microphone or in a direction close to it, the voice of the person making the call cannot be clearly transmitted, resulting in a problem in the transmission quality of the call voice.

The present invention has been made in view of the above circumstances, and provides a stereo sound receiving headset that enables stereophonic transmission with a configuration similar to Combat 1, has excellent call voice transmission quality, and is easy to use. The purpose is to

[Means to solve the problem] FIG. 1 is a block diagram of the principle of the present invention.

In FIG. 1, reference numeral 1 denotes a microphone housing section located near the mouth of a caller in a telephone headset;
2a, 2b, and 3 are microphones (sound receiving parts) for the three omnidirectional electrets 1 provided in the microphone housing 1, and 4 is connected to the microphone 3 to delay the audio signal from the microphone 3. The output delay calculation circuits 5a, 5b are calculation units that subtract the delayed audio signal from the delay calculation circuit 4 from the audio signals from the microphones 2a, 2b, and the microphones 2a, 3. A set of unidirectional microphones is configured by the delay calculation circuit 4 and the calculation unit 5a, and the microphones 2b, 3. Another set of unidirectional microphones is configured by the delay calculation circuit 4 and the calculation unit 5b. Stereophonic sound reception is performed using these two sets of unidirectional microphones.

Moreover, 6a and 6b are microphones 2a and 2b.

The voice signal received by 3 is stereophonically transmitted to the left and right speakers of the other party, and 7 turns on the switch 8 from the off (open) state when the voice level of the caller's voice received by the microphone 3 exceeds a predetermined value. When the switch 8 is turned on (closed), the audio signal from the microphone 3 is transferred to an adder 9 (described later).
It is designed to be output to ports a and 9b. Adders 9a and 9b add the audio signal from the microphone 3 to the audio signals (stereophonically received signals) from the microphones 2a and 2b, respectively.

[For production] With the above-described configuration, the microphones 2a and 2b.

3. Stereophonic sound reception is performed by two sets of unidirectional microphones constituted by the delay calculation circuit 4 and calculation units 5a and 5b, and the environmental sounds around the caller are transmitted to the other party's speaker 6a, 6b stereophonically transmitted. When the control means 7 determines that the sound level received by the microphone 3 exceeds a predetermined value, the control means 7 determines that the caller has uttered a voice.
As a result, switch 8, which is normally off (open), is switched to on (closed), and the audio signal from microphone 3 is added to the audio signals from microphones 2a and 2b by adders 9a and 9b, respectively. , are transmitted to the speakers 6a, 6b of the other party.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

First, the specific structure of the stereo sound receiving type bed set of this embodiment will be explained with reference to FIG. 3. FIG. 3 is a perspective view thereof, and in FIG.
0 is the main body of the headset for talking, 11.11 is a pair of front and rear head belts, 12.12 is a holding frame provided at both left and right ends of the head belt 11, and 13.13 is attached to each holding frame 12 to record the voice of the other party. 14 is a sound receiver holding shaft attached to one of the holding frames 12, 15 is a sound receiver support rod attached to this sound receiver holding shaft 14 so that it can be slid in position, and this sound receiver A microphone storage part 1 is provided at the tip of the support rod 15, and by adjusting the position of the sound receiver support rod 15, the microphone storage part 1 is arranged near the mouth of the person talking.

Further, as shown in FIG. 4, three omnidirectional electronic 1-red microphones (sound receiving sections) 2a, 2b, and 3 are incorporated in the microphone storage section 1. Each of the microphones 2a, 2b, 3 has a diameter of about 5 mm, for example, and is arranged at the apex of an equilateral triangle with an interval of 1 to 2 cm from each other. 3 is on the outside.

FIG. 2 is a block diagram showing an embodiment of the present invention. As shown in FIG. 2, the microphone 3 is connected to a delay calculation circuit 4 that delays and outputs the audio signal from the microphone 3. On the other hand, each microphone 2a, 2b
Arithmetic units 5a and 5b are connected to the arithmetic units 5a and 5b.
a and 5b, the delayed audio signal from the delay calculation circuit 4 is subtracted from the audio signals from the microphones 2a and 2b and output.

Here, as shown in FIG.
a, 3. The delay calculation circuit 4 and the calculation unit 5a constitute a set of unidirectional microphones with a directivity main axis S□, and the microphones 2b, 3. The delay calculation circuit 4 and the calculation unit 5b constitute another set of unidirectional microphones having the directivity main axis S2. These two sets of unidirectional microphones are connected to their directivity main axis S□18
2 at an appropriate angle as shown in Figure 2.4.5, stereophonic reception of environmental sounds around the caller can be achieved using a unidirectional paired microphone pickup system. It has become. The sound collection characteristics of this unidirectional paired microphone sound collection system are shown in Figure 6 (a).
It is shown in the figure below.

On the other hand, the microphone 3 is connected to the control means 7 and also to adders 9a and 9b via a switch 8 which is normally off (open). The control means 7 controls the opening and closing of the switch 8, and includes a level detection section 7a that detects the level of the caller's voice received by the microphone 3.
and a control section 7b that switches the switch 8 from an off (open) state to an on (closed) state when the detection result of the level detection section 7a exceeds a predetermined value. Further, each adder 9a, 9b is provided on the output side of each arithmetic unit 5a, 5b, respectively, and when the switch 8 is turned on, each adder 9a, 9b is provided on the output side of each arithmetic unit 5a, 5b.
audio signals from microphones 2a, 2b,
The audio signal from the microphone 3 is added to the signal stereophonically received by the microphone 3.

Note that 6a and 6b are microphones 2a and 2b.

3 shows the left and right speakers on the opposite side to which the received audio signal is stereophonically transmitted.

With the above-described configuration, the microphones 2a and 2b.

3. Stereophonic sound reception is performed using the paired microphone sound collection method with two sets of unidirectional microphones having a directivity main axis S□182, which are configured by the delay calculation circuit 4 and the calculation units 5a and 5b. Environmental sounds around the caller are stereophonically transmitted to the speakers 6a, 6b of the other party.

At this time, these directional principal axes S1. Since S2 must face in front of (or to the side of) the caller on a horizontal plane, the caller's mouth will be located in or close to the directional blind spot, which will affect the transmission quality of the caller's voice. There is a risk that problems may occur.

Therefore, in this embodiment, the level detection section 7a of the control means 7 detects the sound level received by the microphone 3, and when the control section 7b determines that the sound level exceeds a predetermined value, , it is determined that the caller has uttered a voice, and the control unit 7b turns off (open) normally.
The state switch 8 is switched to the on (closed) state.

As a result, the voice signals of the caller extracted by the microphone 3 are added to the stereophonically received left and right signals from the microphones 2a and 2b (calculating units 5a and 5b) by the adders 9a and 9b, respectively, and The signal is transmitted to the side speakers 6a and 6b.

As described above, according to the present embodiment, a plurality of (three) microphones 2a, 2b,
3 are housed in virtually the same case (microphone housing section 1), and stereophonic sound reception is achieved in a relatively narrow space near the mouth of the caller.
This configuration enables stereophonic transmission, and the headset format allows for hands-free calls, making it extremely easy to use.

Furthermore, when the level detection unit 7a detects the presence of the voice of the caller, it adds the voice signal to the stereophonically received left and right signals. Another advantage is that the sound is clearly transmitted and the transmission quality is greatly improved.

In the above embodiment, three microphones 2 are installed in the microphone housing 1 located near the mouth of the caller.
a, 2b, and 3, but in order to make the microphone storage section 1 smaller and lighter, the microphone storage section 1
In fact, only a sound receiving hole is provided for collecting sound without housing a microphone, and the sound received at the sound receiving hole is collected by a tube installed along the sound receiver support rod 15. , it may be configured such that it is guided to each microphone element incorporated in the sound receiver holding shaft 14.

Furthermore, in the above embodiment, in order to realize stereophonic sound reception, a case has been described in which a paired microphone sound collection system of unidirectional microphones having sound collection characteristics as shown in FIG. 6(a) is adopted. , In addition, there is a paired microphone sound collection system (x-y system) using bidirectional microphones with sound collection characteristics as shown in Figure 6(b), and a sound collection system with sound collection characteristics as shown in Figure 6(c). Even if the m-s microphone sound collection system (hypercardioid pair microphone sound collection system) is adopted, the same effects as those of the above-described embodiments can be obtained.

[Effects of the Invention] As detailed above, according to the stereo sound receiving headset of the present invention, a plurality of sound receiving sections are provided near the mouth of the caller to perform stereophonic sound reception, and When the voice level of the caller exceeds a predetermined value, the voice signal of the caller is added to the stereophonically received signal, making it possible to perform stereophonic transmission with a compact configuration and to provide the voice of the caller. Transport quality and ease of use are greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, Fig. 3 is a perspective view showing the specific structure of the headset of this embodiment, and Fig. 4 is a block diagram showing the specific structure of the headset of this embodiment. FIG. 5 is a block diagram showing the principle of construction of the unidirectional microphone in this embodiment. FIGS. It is a characteristic diagram for explaining a sound method. In the figure, 1 is a microphone storage part, 2a, 2b, 3 are omnidirectional electret microphones (sound receiving part), 4 is a delay calculation circuit, 5a, 5b are calculation units, 6a, 6b are speakers, 7 is a control means, 7a is a level detection unit, 7b is a control unit, 8 is a switch, 9a and 9b are adders, 10 is a headset for talking, 11 is a head belt, 12 is a holding frame, 13 is a headphone, 14 is a receiver holder The shaft 15 is a sound receiver support rod. Big

Claims (1)

[Claims] A sound receiving section (2a, 2b, 3) is located near the mouth of the caller.
A telephone headset is configured to include a plurality of sound receiving sections (2a, 2b, 3) to perform stereophonic sound reception, and when the voice level of the caller exceeds a predetermined value, A stereophonic headset, characterized in that the voice signal of the caller is added to a stereophonically received signal.