JP2002303666A - Microphone unit and position detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology which can detect position information on a speaker. SOLUTION: This microphone unit is composed in one body of an audible- band signal generating means having a sound reception part vibrating with a sound wave of the audible band and a signal-out-of-audible-band generating means having a sound reception part for position detection which vibrates with a sound wave out of the audible band and is moved together with a user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting system, and more particularly to a technology effective when applied to a position detecting system for detecting a position of a speaker such as a caster or a performer.

[0002]

2. Description of the Related Art A conventional position detecting system detects respective positions for a plurality of speakers by analyzing a camera image taken by a television camera or the like in real time. In the position detection using this image analysis technology, for example, each speaker such as casters and performers is dressed in a specific color, and the position information detecting unit detects each speaker in real time from an image taken by a television camera or the like. In addition to extracting the color corresponding to the object as an object, the position information of each speaker is detected based on information such as the arrangement position and the angle of view of the television camera, and the speaker is tracked.

In a position detection system using an image analysis technique, a background image which does not basically move is removed from an image captured by a television camera or the like, and a remaining speaker is extracted as an object, or a stereo camera is used. The speaker is three-dimensionally extracted as an object, and the position of the extracted object is sequentially specified from a camera image captured in real time, thereby tracking the position information of each speaker.

[0004]

SUMMARY OF THE INVENTION As a result of studying the above prior art, the present inventor has found the following problems.

In the position detection system using a camera image, each speaker to be tracked needs to be constantly captured in the camera image. For this reason, for example, if a speaker is hidden behind a set installed in the shooting studio, it is naturally impossible to catch the speaker hidden in the camera image, so tracking this speaker It was impossible to continue.

In a method of basically removing a background image that does not move from an image captured by a television camera or the like and extracting a remaining speaker as an object, the position of the speaker is relatively high while the degree of freedom of the speaker is relatively secured. Can be tracked, but if the speakers are mixed or hidden behind a set, it will not be possible to accurately capture the speaker's location information. It was impossible to keep track of the person.

An object of the present invention is to provide a technique capable of detecting position information of a speaker.

Another object of the present invention is to provide a technique capable of tracking the position of a speaker.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

(1) An audible band signal generating means having a sound receiving portion vibrating by sound waves in the audible band, and an audible out-of-band signal generating means having a position detecting sound receiving portion vibrating by sound waves outside the audible band are integrated. And a microphone device that is moved together with the user.

(2) An audible band signal generating means having a sound receiving portion vibrating by sound waves in the audible band and an audible out-of-band signal generating means having a position detecting sound receiving portion vibrating by sound waves outside the audible band are integrally arranged. Microphone, a speaker that outputs a sound wave outside the audible band of a different frequency in a moving range of the microphone that is moved together with the user, and an electric signal converted from the sound wave collected by the out-of-audible-band signal generation unit. And means for calculating the position of the microphone based on the position information of the speaker.

According to the above-described means, the ultrasonic wave output from the speaker is picked up by the position detecting sound receiving section of the audible out-of-band signal generating means constituting the microphone, and is converted into an electric signal (ultrasonic signal). You. At this time, the microphone having the audible band signal generation means and moved with the subject has a configuration including the audible band out-of-band signal generation means. That is, the microphone has a configuration in which the audible band signal generating means and the audible band out-of-band signal generating means are integrally arranged.

Therefore, based on the ultrasonic signal output from the audible out-of-band signal generating means and the position information of the ultrasonic speaker, the position of the microphone calculated by the calculating means is determined by the following. This is the position of the user who uses the microphone. As a result, when the speaker who is the target moves with the microphone of the present invention carried, the position of the target can be grasped, that is, tracked in real time. At this time, since the voice of the speaker is converted into an electric signal (voice signal) by the audible band signal generating means and output, the movement can be tracked without imposing a burden on the speaker.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention.

In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a diagram for explaining a schematic configuration of a position detecting system according to an embodiment of the present invention. In FIG. 1, 101 is a microphone device, 102 is an ultrasonic speaker, 103 is a position detection device, and 104 is a studio.

As shown in FIG. 1, the position detecting system according to the present embodiment includes a microphone device main body 101 to be mounted by a speaker (caster, cast, or the like) (not shown) for detecting position information; Three ultrasonic speakers 102 respectively arranged at different positions on the ceiling portion
And a position detecting device 103 that supplies an ultrasonic signal as a drive signal to each of the ultrasonic speakers 102. Further, the position detection device 103 of the present embodiment
Are signals in an audible band (sound signal) such as a speaker's voice from an output signal output from the microphone device 101, and a signal outside the audible band such as an ultrasonic wave output from the ultrasonic speaker 102 (ultrasonic signal). And the position information of the microphone device 101 is detected from the separated ultrasonic signal. However, when detecting the position of the microphone device 101, the arrangement position of each ultrasonic speaker 102 is required. In this embodiment, the mutual positions of the ultrasonic speakers 102 are grasped by performing measurement in advance. . The detailed configurations of the microphone device 101 and the position detection device 103 will be described later.

FIG. 2 is a diagram for explaining a schematic configuration of the microphone device of the present embodiment, and FIG. 3 is a diagram for explaining a schematic configuration of the position detecting device of the present embodiment. 2 and 3, reference numeral 201 denotes an ultrasonic microphone unit (out-of-audible-band signal generation unit), 202 denotes an audible-sound microphone unit (audible-band signal generation unit), and 203
Denotes an ultrasonic sound signal multiplexing unit, 301 denotes a sound / position information detecting unit, and 302 denotes an ultrasonic amplifying unit.

As shown in FIG. 2, the microphone device according to the present embodiment includes an ultrasonic microphone unit 201 including an ultrasonic microphone (not shown) and an audible sound (sound) microphone including an audio microphone including two microphone capsules. And a well-known ultrasonic / audio signal multiplexing unit 203 for multiplexing electric signals output from the ultrasonic microphone unit 201 and the audio microphone unit 202.

The ultrasonic microphone unit 201 includes, for example, a known ultrasonic microphone and a known impedance converter for converting the impedance of the ultrasonic microphone.
On the other hand, the audio microphone unit 202 has a so-called lapel microphone (double capsule microphone) configuration including, for example, two microphone capsules and a well-known impedance converter that converts the impedance of each microphone capsule. The detailed structure of the microphone device 101 will be described later.

The ultrasonic / sound signal multiplexing unit 203 includes an electric signal (ultrasonic signal) output from the impedance converter of the ultrasonic microphone unit 201 and an electric signal output from each impedance converter of the sound microphone unit 202. (Audio signal).
However, in the present embodiment, the ultrasonic microphone unit 20
Since the frequency of the ultrasonic wave picked up by 1 is different from the frequency of the sound picked up by the sound microphone unit 202,
The ultrasonic / audio signal multiplexing unit 203 realizes multiplexing of the ultrasonic signal and the audio signal by simply synthesizing the ultrasonic signal from the ultrasonic microphone unit 201 and the audio signal from the audio microphone unit 202. It has become.

The voice / position information detecting unit 301 is for driving the ultrasonic speaker 102 and a well-known separating means (not shown) for separating an ultrasonic signal and an audio signal from a multiplex signal input from the microphone device 101, for example. , And a well-known detection unit (not shown) that detects the position information of the microphone device 101 from the ultrasonic signal separated from the reference signal. However, in the present embodiment, since the three ultrasonic speakers 102 are driven at different frequencies, the reference signal generating means generates the reference signals for three channels and supplies the reference signals to the ultrasonic amplifier 302. Configuration. However, the detection unit of the present embodiment compares the phase of the ultrasonic signal for each frequency separated by the separation unit with the phase of the reference signal, and thereby determines the distance from each ultrasonic speaker 102 to the microphone device 101. In addition to the calculation, the position of the microphone device 101 is calculated in real time based on the mounting position information of each ultrasonic speaker 102.

Here, the principle of the position detection method using ultrasonic waves will be briefly described. Ultrasonic waves that have strong directivity and propagate underwater have been used for fish finder and sonar of submarines for a long time, and the phase difference between oscillated (irradiated) direct wave and reflected wave,
It is useful as a method for measuring the distance of an object from a time difference. Recently, it is often used for measurement of a living body, such as visualization of heart motion using the echo of the liver or the Doppler effect. Therefore, it is introduced in various documents, and the following is
It is an outline.

By measuring the distance from three directions,
The three-dimensional position (x, y, z) of the ultrasonic microphone provided in the microphone device 101 can be determined. The positions and frequencies of the three ultrasonic sound sources are defined as follows.

First, the position of the sound source 1 is determined by (x1, y1, z
As 1), the frequency of the ultrasonic wave output (emitted) from the sound source 1 is f1. Similarly, the position of the sound source 2 is (x
2, y2, z2), its frequency is f2, the position of the sound source 3 is (x3, y3, z3), and its frequency is f3.
However, when the frequencies of the sound sources 1 to 3 are different, any or all of the sound sources 1 to 3 may output ultrasonic waves in the same period, or may output pulses with a time difference between them. May be. Also, when any or all of the sound sources 1 to 3 have the same frequency, it is needless to say that it is necessary to provide a time difference for each pulse and output the pulses.

When the sound source 1 is emitted at the time t1 and the ultrasonic microphone receives the sound at the time t2, the distance d1 between the sound source 1 and the ultrasonic microphone provided in the microphone device 101 is expressed as d1 using the sound velocity v. = V x (t2-t1). Similarly, respective distances d between the sound sources 2 and 3 and the ultrasonic microphone of the microphone device 101 are set.
2, d3 are calculated. In the case where a plurality of ultrasonic pulses are picked up by reflection from a wall surface or the like, in this embodiment, a signal having the largest amplitude is selected, but the present invention is not limited to this. A desired signal can be selected by a combination of a signal or a signal having the largest amplitude and a signal arriving first.

Using the distance from each of the sound sources 1 to 3 to the ultrasonic microphone provided in the microphone device 101,
When a spherical surface is drawn, the position where each spherical surface intersects is the position of the ultrasonic microphone, that is, the microphone device 101.

In this embodiment, the microphone device 101 is provided with one ultrasonic microphone.
It is not limited to this. For example, utilizing the property that ultrasonic waves have high directivity, a plurality of ultrasonic microphones having directivity are provided in the microphone device 101, and the ultrasonic microphones are arranged so that the directivities of the ultrasonic microphones are orthogonal to each other. Here, the mounting direction of the microphone device 101 to a speaker such as a caster or a performer, that is, the directivity direction of each ultrasonic microphone is grasped, and the amplitude and arrival time of the ultrasonic wave collected by each ultrasonic microphone are known. By analyzing the above, in addition to the position of the microphone device 101, that is, the ultrasonic microphone, the arrival direction of the ultrasonic wave can be grasped.
The direction of the speaker can also be specified from the mounting direction of the microphone device 101 to the speaker and the arrival direction of the ultrasonic wave. In particular, when the microphone device is attached to the front of the speaker's chest or the like, the front direction can be specified together with the position of the speaker.

The ultrasonic amplifying unit 302 is a well-known amplifier that amplifies the three-channel reference signals from the audio / position information detecting unit 301 and supplies the signals to the ultrasonic speakers 102 as drive signals.

Next, the operation of the position detecting system according to the present embodiment will be described with reference to FIGS.

First, the reference signal generating means of the voice / position information detecting section 301 constituting the position detecting apparatus 103 converts the reference signals of three different frequencies outside the audible band into the ultrasonic amplifier 3
02. After the reference signals for the three channels are respectively amplified by the ultrasonic amplifier 302, they are supplied as drive signals to the corresponding ultrasonic speakers 102, and drive the ultrasonic speakers 102 attached to the ceiling of the studio 104. . Therefore, each ultrasonic speaker 102 outputs a sound wave having a frequency outside the audible band, that is, an ultrasonic wave.

The ultrasonic wave output from each ultrasonic speaker 102 is collected by an ultrasonic microphone unit 201, and the collected ultrasonic wave is converted into an ultrasonic signal and input to an ultrasonic / audio signal multiplexing unit 203. I do. At this time, the sound microphone unit 202 picks up sound waves in an audible band such as the voice of a speaker (not shown), converts the collected sound waves into sound signals, and inputs the sound signals to the ultrasonic wave / sound signal multiplexing unit 203. .

The ultrasonic signal and the audio signal input to the ultrasonic / audio signal multiplexing unit 203 are multiplexed and then output to the audio / position information detecting unit 301 constituting the position detecting device 103. The transmission of the multiplex signal at this time can be performed by a so-called wired connection that connects the microphone device 101 and the position detection device 103 with a known signal line, or by modulating and amplifying the multiplex signal with a modulation amplifier provided in the microphone device 101. However, any of the so-called wireless connections in which the radio wave is received by the voice / position information detection unit 301 and then demodulated may be used.

The multiplexed signal input to the position detecting device 103 is first separated into an audio signal and an ultrasonic signal by a separating circuit of a sound / position information detecting unit 301 constituting the position detecting device 103. It is output to an audio amplifier or the like that does not. On the other hand, the separated ultrasonic signal is inputted to the detecting means, and the detecting means calculates the sound pickup position, that is, the operation of the microphone device 101 based on the phase analysis for each ultrasonic signal for each frequency and the mounting position of the ultrasonic speaker 102. Is performed, and the obtained position information is output to an automatic tracking camera or the like connected to the subsequent stage.

The above-described output of the ultrasonic wave from the ultrasonic speaker 102 and the calculation of the position of the microphone device 101 from the ultrasonic wave collected by the microphone device 101 are executed in real time.

In this embodiment, the case where the number of ultrasonic sound sources, that is, the number of ultrasonic speakers 102 is three has been described. However, the number of sound sources is not limited to three.
It goes without saying that three or more may be used. Further, the arrangement position of the ultrasonic speaker 102 is not limited to the ceiling portion of the studio 104, and may be arranged on a wall surface, a floor surface, or the like.

FIG. 4 is a diagram for explaining a schematic structure of the microphone device according to the present embodiment. In FIG. 4, 4
01 is an ultrasonic microphone, 402a and 402b are sound wave introduction holes, and 403a and 403b are diaphragms (sound receiving units).

As shown in FIG. 4, the microphone device according to the present embodiment receives a supersonic wave, which is a sound wave outside the audible band, and converts it into an electric signal corresponding to the sound wave outside the audible band. Sound wave microphone 401 and sound wave introduction holes 402a, 4
And sound microphones having vibrating membranes 403a and 403b for converting sound waves in the audible band introduced from 02b into electric signals, respectively.

The microphone device of the present embodiment has a configuration in which a well-known ultrasonic microphone 401 is disposed above the microphone device 101 in order to receive ultrasonic waves output from the plurality of ultrasonic speakers 102, respectively. Has become. Further, the directivity, which is the sensitivity direction of the ultrasonic microphone 401 with respect to the direction of the microphone device 101, is set to be large so that the ultrasonic microphone 401 can receive the ultrasonic waves output from the plurality of ultrasonic speakers 102, respectively. . The ultrasonic microphone 401 according to the present embodiment includes a diaphragm (not shown) for converting a sound wave outside the audible band into an electric signal (ultrasonic signal) and an impedance (not shown) for converting impedance. Since a known configuration including a converter is used, detailed description is omitted.

On the other hand, the audio microphone is composed of an upper microphone capsule having a vibrating membrane 403a arranged at the upper stage,
A so-called lapel microphone (double capsule microphone) including two microphone capsules, including a lower microphone capsule having a vibrating membrane 403b arranged at the lower stage. Rectangular diaphragm 403
This is a so-called condenser microphone having back electrodes (not shown) corresponding to a and 403b. At this time, by arranging the vibration films 403a and 403b such that the longitudinal direction of the rectangular vibration films 403a and 403b is the extending direction of the microphone device 101, that is, the longitudinal direction, the area of each of the vibration films 403a and 403b is increased. Can have a sufficient area, so that the sensitivity of the voice microphone can be improved.

In particular, in the audio microphone according to the present embodiment, the upper microphone capsule is arranged above the microphone device 101, that is, on the side closer to the ultrasonic microphone 401, and the lower microphone capsule is arranged below the microphone device 101, ie, the ultrasonic microphone. It is configured to be arranged on the side far from 401. Further, the upper microphone capsule and the lower microphone capsule are arranged so as to be symmetric with respect to the extending direction (longitudinal direction) of the microphone device 101. That is, the upper diaphragm 403a
And the lower diaphragm 403b are symmetric with respect to the direction in which the microphone device 101 extends.
a, 403b for introducing sound waves into sound wave introduction holes 402a, 402b
02b is also arranged symmetrically with respect to the direction in which the microphone device 101 extends. As a result, in the microphone device 101 of the present embodiment, the difference between the sensitivity and the frequency characteristic between the upper microphone capsule and the lower microphone capsule can be reduced, so that the microphone device 101 is independent with the same sensitivity and frequency characteristics. Output in two audible bands can be obtained.

Further, the microphone device 1 of the present embodiment
01 is an audio microphone composed of two microphone capsules, an upper microphone capsule and a lower microphone capsule.
Even when the ultrasonic microphone 401 is arranged on the upper part of the device 1, sound waves in the audible region such as voice can be collected well.

As described above, in the position detection system according to the present embodiment, the signals are output from the three ultrasonic speakers 102 disposed on the ceiling of the studio 104, which is the moving range of the speaker to be tracked. The ultrasonic waves are collected by a sound receiving unit (not shown) of an ultrasonic microphone 401 included in the microphone device 101, and the vibration of the sound receiving unit is converted into an ultrasonic signal which is an electric signal by a converting unit (not shown). At this time, the microphone device 101 of the present embodiment
Has an audio microphone unit 202, so that the sound of the speaker is picked up and converted into an audio signal, and moves with the movement of the speaker. That is, the microphone device 10
1 includes an ultrasonic microphone unit 201 and an audio microphone unit 202, and multiplexes an ultrasonic signal output from the ultrasonic microphone unit 201 and an audio signal output from the audio microphone unit 202 with an ultrasonic / audio signal. Part 203
Are multiplexed and output to the voice / position information detection unit 301.

Here, the voice / position information detecting unit 301
First, the ultrasonic signal and the audio signal are separated, and then the position of the microphone device 101 is calculated based on the separated ultrasonic signal and the position information of the three ultrasonic speakers 102, so that the speaker The position of the microphone device 101 to be moved together with is determined. As a result, when the speaker who is the subject moves with the microphone device 101 of the present invention being carried or worn, the position of the speaker can be grasped and tracked in real time. At this time, the voice of the speaker is separated from the voice / position information detecting section 301 and then output from the voice / position information detecting section 301. Therefore, the movement of the speaker can be tracked simply by moving with the microphone device 101 of the present invention, and the movement can be tracked without imposing a special burden on the speaker.

As described above, by applying the present invention, even if the performers intersect in a TV conversation program and it is difficult to detect by the conventional image processing, it is possible to use the microphone device 101 of the present invention. Can follow the position of the person. Of course, it is possible to detect the position of the speaker wearing the microphone device 101 even if only tracking using the microphone device 101 is performed without using it together with image processing. Particularly effective when processing is difficult. In particular, when a microphone device 101 having a plurality of ultrasonic microphones having orthogonal directivities is attached to a speaker, the front direction of the speaker can be detected. Shooting can be performed. When photographing is performed only by the microphone device 101 of the present invention without using image processing, the distance between the camera and the speaker is calculated by detecting the position information and the zoom amount of the camera. Even if the speaker moves in the depth direction, the speaker can be tracked with the same photographing size, and can also be used for adjusting the focus of the camera.

The application of the present invention is not limited to automatic tracking of a speaker, but can also be used for elucidation of ecology by attaching it to an animal or the like. Further, the microphone device 101 of the present invention can be attached to a model airplane, a train, or the like, and can be applied to special photography. Further, the microphone device 101 of the present invention may be attached to a control device such as a robot controlled by remote operation or a preset action plan, and the position of the control device may be monitored.

In the present embodiment, the microphone device 101 is an ultrasonic microphone unit 2 for detecting ultrasonic waves.
01 and the audio microphone unit 202 for detecting audio are integrally formed, but the ultrasonic microphone unit 201 and the audio microphone unit 202 are configured to be separable from each other, and position information of the microphone device 101 is obtained. Ultrasonic microphone 40 only when necessary
Needless to say, the above-described effects can be obtained even when the microphone 1 is attached to the microphone device 101.

In the present embodiment, two microphone capsules are arranged vertically, but the present invention is not limited to this.
It is needless to say that the ultrasonic microphone 401 may be arranged in the middle part of 01, and the microphone capsules may be arranged on the left and right sides of the ultrasonic microphone 401, respectively, to make the microphone device 101 horizontally long.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .

[0051]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) Based on the phase of the ultrasonic wave picked up by the ultrasonic microphone section of the microphone device and the position information of the ultrasonic speaker that outputs the ultrasonic wave, the sound / position information detecting section detects the ultrasonic microphone. Since the position of the microphone device where the unit is arranged is detected, it is possible to detect the position information of the speaker moving together with the microphone device.

(2) By detecting the position information of the speaker moving with the microphone device in real time,
Since the position of the speaker can always be specified, the movement of the speaker can be tracked.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a schematic configuration of a position detection system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of a microphone device according to the present embodiment.

FIG. 3 is a diagram for explaining a schematic configuration of a position detection device according to the present embodiment.

FIG. 4 is a diagram illustrating a schematic structure of the microphone device according to the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 ... Microphone device 102 ... Ultrasonic speaker 103 ... Position detection device 104 ... Studio 201 ... Ultrasonic microphone unit 202 ... Audible sound microphone unit (audio microphone unit) 203 ... Ultrasonic / audio signal multiplexing unit 301 ... Audio /
Position information detection unit 302 ... ultrasonic amplification unit 401 ... ultrasonic microphones 402a, 402b ... sound wave introduction holes 403a, 40
3b ... vibrating membrane

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masakazu Iwaki 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute (72) Inventor Shinichi Chiba 1-10-11 Kinuta, Setagaya-ku, Tokyo No. Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Yuri Hatakeyama 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Research Institute (72) Inventor Takao Tsuda 1-10 Kinuta, Setagaya-ku, Tokyo No. 11 Japan Broadcasting Corporation Broadcasting Research Laboratory (72) Inventor Daiichiro Kato 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Research Laboratories F-term (reference) 5J083 AA05 AB15 AC29 AD01 AE08 BA16 CA03 CA10

Claims (9)

[Claims] 1. An audible band signal generating unit having a sound receiving unit vibrating by a sound wave in an audible band, and an audible out-of-band signal generating unit having a position detecting sound receiving unit vibrating by a sound wave outside the audible band are integrally formed. A microphone device configured and moved with a user. 2. The microphone device according to claim 1, wherein said sound receiving portion is formed of a rectangular diaphragm, and said audible band signal generating means is formed of two microphone capsules having said sound receiving portion. A microphone device characterized by the above-mentioned. 3. The microphone device according to claim 2, wherein the two microphone capsules are arranged on a straight line and symmetrically with respect to an intermediate position between the two microphone capsules. 4. The multiplexing apparatus according to claim 1, wherein an output from said audible band signal generating means and an output from said out-of-audible band signal generating means are multiplexed. A microphone device comprising means. 5. The microphone device according to claim 1, wherein the position detecting sound receiving unit includes an ultrasonic microphone unit having a desired directivity of two or more, and A microphone device, wherein the microphone units have directivities set in different directions. 6. An audible band signal generating unit having a sound receiving unit vibrating by an audible band sound wave and an audible out-of-band signal generating unit having a position detecting sound receiving unit vibrating by a sound wave outside the audible band are integrally formed. A microphone that outputs sound waves outside the audible band of different frequencies in a moving range of the microphone that is moved together with a user,
Based on the electric signal converted from the sound wave collected by the audible out-of-band signal generation means and the position information of the speaker,
Means for calculating the position of the microphone. 7. The position detection system according to claim 6, wherein said sound receiving section is formed of a rectangular diaphragm, and said audible band signal generating means is composed of two microphone capsules having said sound receiving section. A position detection system characterized by: 8. The position detection system according to claim 7, wherein said speakers comprise three or more speakers each outputting sound waves having different frequencies. 9. The position detection system according to claim 1, wherein the position detection sound receiving unit comprises an ultrasonic microphone unit having a desired directivity of two or more. A position detection system, wherein the acoustic microphone unit has directivity set in different directions.