JPH1118192A - Sound pickup method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound pickup method and its device by which a sound is picked up by precisely directing the directivity of a microphone array in a direction of an object sound. SOLUTION: A signal picked up by a microphone array 21 is given to a microphone array master set 22, where the signal is processed, the directivity of the microphone array 21 is directed to an existing area of an object speaking person, to pick up an object voice signal with high S/N, and the picked-up voice signal is sent through a transmission line 23-2. A received signal from a communication destination via a reception line 23-1 is emitted from a reception loudspeaker 24 as a received voice signal. At this time, a reception detection section 30 detects a reception state, and a directivity control section 40 controls the directivity of the microphone array 21, based on the detected reception state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound pickup method and a sound pickup apparatus for processing a signal output from a microphone array composed of a plurality of microphones to pick up sound. Method and apparatus for detecting received voice when applied to telecommunications conferences in Japan, and aiming at the directivity of the microphone array in the direction of the target voice accurately by removing the effect of the received voice radiated from the receiving speaker The present invention relates to a sound collecting method and device capable of picking up sound.

[0002]

2. Description of the Related Art In recent years, with the advancement of multimedia technology, it has become possible to conduct a teleconference such as a video conference using a microphone and a speaker in a voice call mode.
In such a case, there is a need for a sound collecting device capable of making a natural call without being aware of the microphones and installing only a target sound such as voice without installing microphones for the number of speakers on the desk of the communication conference. I have.

[0003] As an example of such a sound pickup device, there is a sound pickup device in which a plurality of microphones (microphone arrays) are installed and their outputs are subjected to signal processing to extract a target sound. Signal processing methods for suppressing noise and extracting a target sound using such a microphone array include a delay-and-sum method,
Many are known such as MNOR (for example, Oga, Yamazaki,
Kanada, "Acoustic system and digital processing", IEICE, 1995, pp. 173-197) For example, in the delay-and-sum method, a target sound is extracted as follows.

FIG. 10 is a diagram for explaining the principle of target extraction by the delay-and-sum method. In FIG. 10, 1 is a sound collection unit (microphone array), 2 ₁ , 2 ₂ ,..., 2 _M are microphones (M is the number of microphones), 3 ₁ , 3 ₂ ,
..., 3 _M is a delay device, 4 is an adder, 5 is an output signal, 6
Is a noise suppression unit, d is a microphone interval, s (t) is a sound wave arriving at the sound collection unit 1 (t represents time), and θ is a sound wave s
(T) is an arrival angle at which the sound arrives at the sound pickup unit 1, and τ is a time difference (delay time) at which a sound wave reaches each microphone.

[0005] The microphones 2 ₁ , 2 ₂ ,.
, 2 _M are arranged linearly at equal intervals d, and the sound wave s (t) arrives at microphones arranged at an angle θ from a distance. The distance the sound wave reaching the microphone 2 ₁ propagates before reaching the microphone 2 _2, dsin from a microphone spacing d and the angle of arrival θ
It is represented by θ. Similarly, the i-th microphone 2 _i (i
= 2,..., M)
(I-1) It is represented by dsinθ. Accordingly, the microphone _{2 i (i = 2, ···} , M) is a delay time tau _i to reach, when the reference microphone 2 _1, by dividing the propagation distance at the speed of sound c, the following equation (1 ).

[0006]

(Equation 1) Here, when an output signal from each microphone 2 _i (i = 1,..., M) is represented by X _i (t), this is a sound wave s
Since (t) is delayed by τ _i , the following equation (2) is obtained.

[0007]

(Equation 2) Here, if the delay amount D _i of the delay unit 3 _i (i = 1, 2,..., M) is appropriately set, only the sound wave arriving from the θ direction can be emphasized and output to the output signal 5. Shown in

The delay amount D _i of the delay unit 3 _i (i = 1, 2,..., M) is set as in the following equation (3).

[0009]

(Equation 3) D ₀ is a fixed delay amount added to prevent a decrease in accuracy when realizing delay characteristics with a digital filter when the value of τ _i is too small.

At this time, the delay units 3 _i (i = 1, 2,...)
, M) is obtained by adding the signal of equation (2) to the delay D of equation (3).
_{Since i} occurs, the following equation (4) is obtained.

[0011]

(Equation 4) That is, regardless of the microphone number i, s (t)
Is the same signal delayed by D ₀ .

If the signals are added by the adder 4 after the phases are aligned in this way, the sound waves arriving from the θ direction are emphasized by the added amount. On the other hand, sound waves and theta directions coming from another theta _N direction, since it is sound receiving with different delay times tau _N and tau _i, the phase is not aligned in the delay amount of a compound of formula (3), by the adder 4 Addition of the signals does not add emphasis.

As described above, in the delay-and-sum method, a sound wave arriving from a target direction θ is emphasized, and noise arriving from another direction θ _N is relatively suppressed.

At this time, if the output signal of the microphone array is monitored by scanning the target direction θ and the output signal of the microphone array is monitored, the output signal becomes large when θ is directed to the target speaker. Can be. Then, the target sound is raised by aligning and adding the phases according to equation (4) so as to emphasize the sound wave from the direction θ of the target speaker, that is, by directing the directivity of the microphone array in the direction of θ. Sound can be collected at the SN ratio.

Here, for convenience of explanation, a plurality of microphones are described as being arranged on a straight line at equal intervals d. However, the microphones can be arranged at irregular intervals, and the arrangement shape is two-dimensional. They may be arranged in three dimensions.

When the sound source S, which is a point sound source, is located at a relatively short distance from the array as shown in FIG. 11, the delay devices 3 ₁ , 3 ₂ are utilized by utilizing the properties of the spherical wave from the sound source S. , ...
, 3 _M , and gains 7 ₁ , 7 ₂ ,..., 7 _M are provided at the subsequent stage, and applying an appropriate load to these gains is important for improving the sound pickup SN ratio. There is a way of applying the load as represented by the following formulas (5), (6), and (7) (Nomura, Kaneda, Kojima “Near-field microphone array”, Journal of the Acoustical Society of Japan, 53 Vol. 2 (1997), p.
p. 110-116).

[0017]

(Equation 5)

[0018]

(Equation 6)

[0019]

(Equation 7) Here, r ₁ , r ₂ ,..., R _M are the distances from the sound source S to the microphones 2 ₁ , 2 ₂ ,..., 2 _M , and r _C is the critical distance in the room, that is, the direct sound power of the sound source. This is a distance at which the reverberation sound power becomes equal. For a room volume V [m ³ ] and a room reverberation time T [second], r _C = √ (0.0032 V /
T) (H.Kuttruff, “RoomAcoustics (Thir
d Edition) ", Elsevier Applied Science, pp. 100-132
(1991)). At this time, the microphone array has the highest sensitivity with respect to the "point" of the position of the sound source S, so that a "focus" of the sensitivity is formed. At this time,
Distance r _i to each microphone (i = 1, 2,...,
Delayer 3 for _{M) 1, 3 2, ···} , 3 M of delay D
₀ -r _i / c (c: sound velocity) and by changing the above-mentioned gain g ₀ i.e. a scan the focal point of the sensitivity, by monitoring an array output, the focus sensitivity in terms of the presence of the target speaker direction Since the array output becomes large when it is, the position of the target speaker can be found by this.

In this way, by finding the target speaker's existence area as the direction or position, and directing the array directivity to the existence area, the target sound can be picked up with a high sound pickup SN ratio.

[0021]

An attempt is made to apply this microphone array to a communication conference such as a video conference. The advantage of using a microphone array for the sound pickup section of a teleconference is that the microphone array can be installed at a position away from the speaker with a high sound collection S / N ratio, and it is necessary to install multiple microphones on the desk. There is an advantage that the user is not conscious of the microphone and a natural telephone call is possible.

FIG. 12 shows an example of a communication conference apparatus using the microphone array as a sound pickup unit. In this figure, 10A, 1
0B is a communication conference room, 11A and 11B are microphone arrays, 12A and 12B are microphone array main devices, 13
Represents a communication line, and 14A and 14B represent receiving speakers.
The target voice uttered in the communication conference room 10A is picked up by the microphone array 11A, and the microphone array main device 1
After the process of emphasizing the target voice in 2A, the voice is transmitted to the communication conference room 10B, which is the communication destination, through the communication line 13, and is radiated from the receiving speaker 14B as the received voice. The flow of the signal for the target voice uttered in the communication conference room 10B is the same as the flow described above. The microphone array main units 12A and 12B scan the directivity of the microphone arrays 11A and 11B to find the target speaker's existence area as described above, and
1B operates so that the directivity is directed to the area where the target speaker is present, and operates so that the target voice is collected at a high SN ratio.

As described above, the microphone array 11A, 1
1B has an effect of detecting the target speaker's existence area, directing the directivity of the microphone arrays 11A and 11B to this existence area, and collecting the target sound at a high SN ratio. However, the receiving voice from the communication destination is
When radiated from A or 14B, the receiving speaker is often erroneously detected as a target speaker, and the directivity of the microphone arrays 11A and 11B is
It turned out that it turned to the direction of A or 14B. Further, at this time, the sound radiated from the receiving speaker 14A or 14B is picked up by the microphone array 11A or 11B, and is again returned to the communication conference room 10A or 1A where the speaker is present.
It has also been found that there is a problem that the communication quality deteriorates due to perception as an echo or howling or the like when returning to 0B.

[0024]

In order to solve the above-mentioned problem, it seems that the directivity of the microphone array should not be directed to the direction of the receiving speaker. However, even in this case, the directivity of the microphone array is oriented near the receiving speaker (at a position slightly away from the receiving speaker). As a result, reflected sound from a wall or floor near the receiving speaker is collected. In order to solve this problem, directivity is not suitable even near a receiving speaker. However, in this case, when the target speaker speaks at a position close to the receiving speaker, the directivity does not go in the direction of the target speaker, and good sound collection cannot be performed.

Therefore, according to the present invention, first, a receiving section for detecting a receiving state in which the receiving voice exists is provided in order to distinguish the target voice emitted by the target speaker from the receiving voice radiated from the receiving speaker. A directivity control unit is provided for preventing the directivity of the microphone array from being directed to the receiving speaker, the area near the receiving speaker, or a specific area set based on the receiving state detected by the receiving detecting unit. That is, by performing the directivity control for avoiding the receiving speaker only in the receiving state, the control that does not affect the sound pickup of the target speaker can be realized.

The most basic method for detecting a reception is a method of monitoring an electric reception signal transmitted from a destination. The reception can be detected, for example, by calculating the power of the reception electric signal and determining whether or not the power has exceeded a certain threshold th1. As a more complicated reception detection method, for example, a reception detection technology used in a voice switch technology, an acoustic echo canceller technology, or the like can be used.

If this method cannot be used, for example, because an electrical reception signal cannot be extracted, the directivity of the microphone array is directed to the reception speaker, and the output signal of the microphone array at this time is monitored. For example, the received signal can be determined by determining whether the power of the output signal exceeds the threshold th2.

When the delay-and-sum method shown in FIG. 10 or FIG. 11 is used as a signal processing for the microphone array output, the directivity is generally sharper at a high frequency. Therefore, if high-frequency components are used, even if there is a speaker or noise source near the receiving speaker, the sound waves emitted from the receiving speaker must be separated from the sound waves emitted from these speakers and collected. The received voice can be detected by distinguishing the received voice radiated from the receiving speaker. To extract the high frequency components, the output of the microphone array for the receiving speaker can be extracted by passing it through a high frequency filter. In addition, even when electrical reception detection is performed,
If the receiving state cannot be detected properly because unnecessary low frequency electric noise is superimposed on the electric receiving signal, for example, high-pass filtering is performed to remove the low frequency electric noise. The use of the receiver makes it possible to detect the receiving state satisfactorily.

The most basic method of directivity control is a method of excluding the position of the receiving speaker from the directivity scanning range for detecting the target speaker while the receiving detector determines that the receiving state is set. However, this is not enough for practical use. That is, the first reflected sound for the sound radiated by the receiving speaker is generated from the floor / wall in the area near the receiving speaker. Generally, since the first reflected sound has high energy, the microphone array may perform erroneous detection due to the influence of the reflected sound. In order to prevent this, a directivity control unit is provided to prevent directivity of the microphone array from being directed not only to the position of the receiving speaker but also to a region near the receiving speaker including the receiving speaker position. Note that the area near the receiving speaker is a radius of 0. 0 around the receiving speaker.
The size of the actual radius is determined depending on conditions such as the purpose of sound collection and the degree of reflection and noise of the room to be used. However, it is desirable that the size be large as long as it does not overlap with the area where the target speaker exists.

In this way, the receiving speaker position is not erroneously detected as the target speaker position. In addition, when not receiving, the entire area of the target area is scanned and detected. Therefore, even when the target speaker is generated near the speaker, its position can be detected and the directivity can be directed to the target speaker. Sound can be realized.

In the case where the sound pressure of a specific area in the room other than the area near the receiving speaker is increased due to the reflection of the received voice radiated from the receiving speaker in the room or the noise coming from the air conditioner or the window or wall of the room, The specific area is also set so as to be excluded from the directivity scanning range together with the receiving speaker or the area near the receiving speaker.

In order to realize the same purpose,
The following method is also applicable. When detecting the target speaker's presence area by directing the directivity to the area where the average power of the array output is high, the power calculation for each area to calculate the power for each area when scanning the directivity Unit, and calculates the power for each area except the receiving speaker, the area near the receiving speaker, and the specified specific area, and detects a high-power area as a sound source area from the power calculated by the power calculating unit for each area. can do. In this way, it is possible to avoid a problem that the receiving speaker, the area near the receiving speaker, or the specified specific area is erroneously detected as the target speaker's existing area.

Further, in order to realize the same purpose, the following method can be applied. That is, from the output of the power calculation unit for each area that calculates the power for each area when the directivity is scanned, the power having the highest power among the powers for the areas other than the receiving speaker or the area near the receiving speaker or the specified specific area is selected. The region may be detected as the sound source region.

As a measure for reliably preventing erroneous detection in the area near the receiving speaker during the receiving state, the receiving section is turned immediately before the receiving state is detected while the receiving detecting section determines that the receiving state is in the receiving state. The directivity of the microphone array is fixed by the directivity control unit in the region where the microphone array is located.

The method described here for detecting the sound wave radiated from the receiving speaker and preventing the directivity of the array from being directed to the receiving speaker, the area near the receiving speaker, or a specific area set, is based on a method in which the uttered voice of the speaker is output. The present invention can also be applied to in-field loudspeaker in which sound is picked up and loudspeakers are used in the same room where the speaker is located. For example, when a listener asks a question in a lecture or the like in a relatively large venue, the question of the listener is loudspeaked in a loudspeaker or the like in order to make the content of the question easier to hear. It is conceivable to direct the directivity to the listener using the microphone array when collecting the listener's question.However, when the energy of the sound wave radiated from the loudspeaker is large, the microphone array asks a question. There is a possibility that a speaker for loudspeaker other than the listener who is listening may be erroneously detected as a speaker. In order to prevent this, a method of controlling the directivity except for the loudspeaker for loudspeaker, the area near the loudspeaker for loudspeaker, or the set specific area may be considered.

[0036]

According to the present invention, by providing a reception detector for detecting a reception state in which a reception voice exists, the target voice emitted by the target speaker and the reception voice radiated from the reception speaker are provided. Can be identified. By providing a directivity control unit that prevents the directivity of the microphone array from directing to the receiving speaker or a specific area set in the vicinity of the receiving speaker or the receiving speaker based on the receiving state detected by the receiving detection unit, The effect of the radiated received voice can be prevented, and the operation of erroneously turning the directivity of the microphone array to the receiving speaker in which the target voice does not exist, the area near the receiving speaker, or the specified specific area can be prevented.

[0037]

An embodiment will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In this figure, reference numeral 20 denotes a communication conference device, which includes a microphone array 21, a microphone array main device 22, a receiving line 23-1 serving as a receiving means,
A transmission line 23-2 serving as a transmission means, and a reception speaker 24;
And a reception detection unit 30 and a directivity control unit 40.

In operation, the signal picked up by the microphone array 21 is subjected to signal processing by the microphone array main unit 22, and the directivity of the microphone array 21 is directed to the area where the target speaker exists. High SN
The sound is collected at the ratio, and the target voice is transmitted to the communication destination through the transmission line 23-2. A reception signal received from a communication destination via the reception line 23-1 is radiated by the reception speaker 24 as reception voice. At this time, in order to prevent the directivity of the microphone array 21 from being erroneously directed to the receiving speaker 24 where the target speaker is not speaking or the area near the receiving speaker 24, the receiving state is detected by the receiving detector 30. , The directivity control unit 4 based on the detected reception state.
0 controls the signal processing of the microphone array main device 22 and controls the directivity of the microphone array 21.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, a reception signal power calculation unit 31 for calculating the power of a reception signal and a reception state when the power of the reception signal calculated by the reception signal power calculation unit 31 exceeds a set threshold th1. This is an embodiment in which the receiving state determining unit 32 and the receiving state determining unit 32 are configured to determine the receiving state by calculating the power of the receiving signal.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the receiving speaker 24 or the receiving speaker 24
A receiving speaker output sound collecting unit 33 for directing the directivity of the microphone array 21 to a nearby area or a specific area, a receiving speaker output power calculating unit 34 for calculating the power of an output signal from the receiving speaker output sound collecting unit 33, An embodiment in which the reception detection unit 30 is constituted by the reception state determination unit 32 that determines the reception state when the reception speaker output power calculated by the reception speaker output power calculation unit 34 exceeds the set threshold th2. It is.

FIG. 4 shows a fourth embodiment of the present invention. In this embodiment, a band filtering unit 50 for extracting a specific band component of a received signal is provided, and the reception detecting unit 30 detects a reception state using an output signal of the band filtering 50. It is an example.

FIG. 5 shows a fifth embodiment of the present invention. This is because the directional scanning unit 41 that scans the directivity of the microphone array 21, the sound source existence region detecting unit 42 that detects the target speaker region from the output signal of the directional scanning unit 41, and the reception detecting unit 30 While the state is determined, the receiving speaker 2
This is an embodiment in which the directivity control unit 40 is configured by a sound source existence region detection limiting unit 43 that excludes a region 4 or a region near a receiving speaker or a set specific region from detection of a sound source existence region.

FIG. 6 shows a sixth embodiment of the present invention. In this embodiment, a region-specific power calculator 421 that calculates the power of the output signal of the directional scanning unit 41, and a region-specific power maximum region that detects the region where the power calculated by the region power calculator 421 is the maximum This is an embodiment in which the sound source existence region detecting unit 42 is constituted by the detecting unit 422.

FIG. 7 shows a seventh embodiment of the present invention. In this embodiment, a directional scanning unit 41 that scans the directivity of the microphone array 21 and each area excluding the receiving speaker 24 or the area near the receiving speaker or a set specific area while the receiving detection unit 30 determines the receiving state. Area power calculation section 421 for calculating the power of the output signal of the directional scanning section 41, and an area maximum power detection section for detecting an area where the power calculated by the area power calculation section 421 is maximum. 422 is an embodiment in which the sound source existence area detection unit 42 is configured from 422 and 422.

FIG. 8 shows an eighth embodiment of the present invention. In this embodiment, the directivity scanning unit 41 that scans the directivity of the microphone array 21 and the directivity to the receiving speaker 24, the area near the receiving speaker, or the specified specific area while the receiving detection unit 30 determines that the receiving state is set. A scan limiting unit 44 that inhibits the scanning of, a directional scan limited output power calculation unit 45 that calculates the power of the output signal of the directional scan unit 41,
This is an embodiment in which the directivity control unit 40 is configured by a directivity scan only output power maximum area detection unit 46 that detects an area where the power calculated by the directivity scan only output power calculation unit 45 is maximum.

FIG. 9 shows a ninth embodiment of the present invention. This embodiment is an embodiment in which the directivity holding unit 47 for fixing the directivity of the microphone array 21 is provided in the directivity control unit 40 while the reception detection unit 30 determines that the reception is detected.

[0048]

As described above, according to the sound collecting method of the present invention, sound is collected using a microphone array including a plurality of microphones and a microphone array main device that performs signal processing on an output signal of the microphone array. In the sound collection method to be performed, a reception signal from a communication destination is received, the reception signal is emitted from a reception speaker as a reception sound wave, a reception state is detected from the reception signal or the reception sound wave, and the directivity of the microphone array is detected. Since the control is performed, the directivity of the microphone array can be accurately controlled.

Further, the sound collection device of the present invention is provided with a reception detection unit for detecting a reception state in which a reception voice exists, thereby distinguishing the target voice emitted by the target speaker from the reception voice radiated from the reception speaker. Will be able to By providing a directivity control unit that prevents directing the array from directivity to the receiving speaker, the receiving speaker vicinity area, or a specified specific area based on the receiving state detected by the receiving detection unit, radiation from the receiving speaker is provided. The influence of the received voice can be prevented, and the operation of erroneously directing the directivity of the microphone array to the receiving speaker in which the target voice does not exist, the area near the receiving speaker, or the specified specific area can be prevented.

As described above, according to the present invention, the sound radiated from the speaker can be prevented from being picked up by the microphone array, and the sound uttered by the speaker can be transmitted again through the line. It is possible to prevent echoes returning to the room where the user is located, and also to prevent howling, thereby achieving an unprecedented excellent effect of preventing deterioration in call quality due to these echoes and howling.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a first embodiment of a sound collection device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of the sound collection device of the present invention.

FIG. 3 is a block diagram showing a configuration of a third embodiment of the sound collection device of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a fourth embodiment of the sound collection device of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a fifth embodiment of the sound collection device of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a sixth embodiment of the sound collection device of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a seventh embodiment of the sound collection device of the present invention.

FIG. 8 is a block diagram showing a configuration of an eighth embodiment of the sound collection device of the present invention.

FIG. 9 is a block diagram showing a configuration of a ninth embodiment of a sound collection device of the present invention.

FIG. 10 is a diagram for explaining the principle of noise suppression sound collection by the conventional delay-and-sum method.

FIG. 11 is a diagram for explaining that, when the sound source is located at a position close to the microphone array, the gain load at the subsequent stage of the delay unit is appropriately set to improve the sound collection SN ratio.

FIG. 12 is a block diagram for explaining a conventional communication conference using a microphone array.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 Communication conference device 21 Microphone array 22 Microphone array main device 23-1 Receiving line 23-2 Transmitting line 24 Receiving speaker 30 Receiving detecting unit 31 Receiving signal power calculating unit 32 Receiving state determining unit 33 Receiving speaker output sound collecting unit 34 Receiving Speaker output power calculation unit 40 Directivity control unit 41 Directivity scanning unit 42 Sound source existence region detection unit 421 Region-specific power calculation unit 422 Region-specific power maximum region detection unit 43 Sound source existence region detection and limitation unit 44 Scan limitation unit 45 Directional scanning Limited output power calculation unit 46 Directional scanning limited output power maximum area detection unit 47 Directivity hold unit 50 Band filtering unit

Claims (10)

[Claims] In a sound collection method for collecting sound using a microphone array including a plurality of microphones and a microphone array main device that performs signal processing on an output signal of the microphone array, a reception signal from a communication destination is received. And radiating the reception signal as a reception sound wave from a reception speaker, detecting a reception state from the reception signal or the reception sound wave, and controlling the directivity of the microphone array. 2. A sound pickup device for picking up sound using a microphone array including a plurality of microphones and a microphone array main device that processes an output signal of the microphone array. Means, a receiving speaker that radiates a receiving signal from the receiving means as a receiving sound wave, a receiving detecting unit that detects a receiving state from the receiving signal or the receiving sound wave, and a receiving state signal output from the receiving detecting unit. A sound pickup device comprising a directivity control unit for controlling the directivity of the microphone array based on the directivity control unit. 3. The sound collection device according to claim 2, wherein: a reception signal power calculation unit that calculates the power of the reception signal;
A receiving state detecting unit configured to determine a receiving state when the receiving signal power calculated by the receiving signal power calculating unit exceeds a set threshold value; apparatus. 4. The sound pickup device according to claim 2, wherein a sound receiving speaker output sound pickup unit for directing the directivity of the microphone array to the sound receiving speaker, an area in the vicinity of the sound receiving speaker, or a designated specific area. A receiving speaker output power calculating unit for calculating an output signal power from the speaker output sound collecting unit, and a receiving state when the receiving speaker output power calculated by the receiving speaker output power calculating unit exceeds a set threshold value And a receiving state determining unit for determining the receiving state. 5. The sound pickup device according to claim 2, wherein a directivity scanning unit that scans the directivity of the microphone array, and an area where a target sound source exists based on an output signal of the directivity scanning unit. A sound source existence area detecting unit for detecting the sound, and prohibiting directing of the microphone array to the receiving speaker, an area near the receiving speaker, or a specified specific area while the receiving detecting unit determines that the receiving state is set. A sound collection device, wherein the directivity control unit is constituted by a sound source existence region detection limiting unit. 6. The sound pickup device according to claim 5, wherein the power calculation unit calculates the power of the output signal of the directional scanning unit, and the power calculated by the power calculation unit is maximum. A sound pickup apparatus comprising: a sound source existence region detection unit including a region-specific power maximum region detection unit that detects a directional scanning region. 7. The sound pickup apparatus according to claim 2, wherein said directional scanning unit scans the directivity of said microphone array, and said reception unit detects said reception state while said reception detection unit determines that said reception state is set. A region-by-region power calculation unit for calculating the power of the output signal of the directional scanning unit for the speaker or the region other than the vicinity region or the designated specific region of the reception speaker; and the power calculated by the region-by-region power calculation unit. A sound collecting apparatus, wherein the directivity control unit is configured by a region-specific power maximum region detection unit that detects a region that is maximum. 8. The sound pickup device according to claim 2, wherein said directional scanning unit scans the directivity of said microphone array, and said receiving unit detects said receiving state while said receiving state detecting unit determines said receiving state. A loudspeaker or a scan limiting unit for inhibiting the directional scanning of a specified area or a neighborhood area of the receiving speaker; a directional scanning limited output power calculating unit for calculating the power of an output signal of the directional scanning unit; A sound pickup device comprising: a directional scanning limited output power maximum area detecting section for detecting an area where the power calculated by the directional scanning limited output power calculating section is maximum; . 9. The sound pickup device according to claim 2, further comprising a band filter for extracting a specific band component of the reception signal or an output signal from the reception speaker output sound pickup unit. A sound collection device, wherein the reception detection unit detects a reception state using an output signal of the band filtering unit. 10. The sound pickup device according to claim 2, wherein the directional hold unit for fixing the directivity of the microphone array is provided while the receiving detection unit determines that the receiving state is set. A sound pickup device provided in a control unit.