JP2017097015A - Active silencing system, active silencing method, and active silencing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To silence, at an arbitrary target position, a sound wave from a sound source by using a plurality of silencers arranged around the sound source.SOLUTION: According to an embodiment, an active silencing system includes at least one sensor, at least one microphone, and a plurality of speaker units. The sensor detects information on a target position. The microphone receives a first sound wave output from a sound source and generates a first sound signal. At least one speaker unit, which is selected on the basis of the target position from among the plurality of speaker units, outputs a second sound wave blocking the first sound wave at the target position, on the basis of the first sound signal.SELECTED DRAWING: Figure 1

Description

  Embodiments relate to active silencing techniques.

  2. Description of the Related Art Conventionally, a technique is known in which a sound wave propagating one-dimensionally, for example, noise in a duct, is silenced by outputting a sound wave corresponding to the opposite phase wave of the sound wave. Furthermore, an active acoustic shielding technique has been proposed for silencing sound waves that propagate three-dimensionally. In this technique, a plurality of silencers each including a microphone and a speaker are densely arranged in an array. Then, each silencing device quickly outputs a sound wave corresponding to the opposite phase wave of the sound wave received by its own microphone from its own speaker, thereby constructing a silencing space using Huygens' principle.

  In the conventional active acoustic shielding technology, it is necessary to arrange a plurality of silencers in an array. Furthermore, since the microphones and speakers of all the silencers operate steadily, a microphone of a certain silencer receives sound waves output from the speakers of other nearby silencers, and howling may occur. For this reason, the silencer used in this active sound shielding technique must be kept in complicated installation conditions, so that it is difficult to change the arrangement and is not suitable for carrying.

JP 2001-295622 A JP 2001-174538 A

Tatsuya Murao and Masahara Nishimura, “Basic study on active acoustic shielding,” Journal of environment and engineering, vol. 7, no. 1,76p, 2012 Xun Wang et al. , “Hybrid active noise with sound masking,” Processeds of the 43th International congress and exposure on noise control 14 (20)

  The embodiment aims to mute sound waves from the sound source at an arbitrary target position using a plurality of silencers arranged around the sound source.

  According to the embodiment, the active silencing system includes at least one sensor, at least one microphone, and a plurality of speaker units. The sensor detects information related to the target position. The microphone receives the first sound wave output from the sound source and generates a first sound signal. At least one speaker unit selected based on the target position among the plurality of speaker units outputs a second sound wave that inhibits the first sound wave at the target position based on the first sound signal.

The figure which illustrates the active silence system concerning a 1st embodiment. The block diagram which illustrates the silencer of FIG. FIG. 2 is a block diagram illustrating the parent device in FIG. 1. The flowchart which illustrates operation | movement of the active silencing system of FIG. The figure which illustrates the active silence system concerning a 2nd embodiment. The figure which illustrates the active silence system concerning a 3rd embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. Hereinafter, the same or similar elements as those already described are denoted by the same or similar reference numerals, and redundant description is basically omitted. For example, when there are a plurality of identical or similar elements, a common reference may be used to explain each element without distinction, and the common reference may be used to distinguish each element. In addition, branch numbers may be used.

(First embodiment)
As illustrated in FIG. 1, the active silencer system according to the first embodiment includes a plurality of (four in the example of FIG. 1) silencers 100-1, 100-2,. ··including. The silencer 100 includes at least a sensor unit and a speaker unit. Note that the number of speaker units and sensor units provided in the silencer 100 may be plural. If the muffler 100 includes a plurality of speaker units and sensor units, it is possible to simultaneously provide a mute effect to be described later to a plurality of target positions.

  The sound source is a generation source of the first sound wave to be silenced by the active silencing system. The sound source may be a human, an animal or a machine. The total number of sound sources may be two or more.

  In the example of FIG. 1, the muffler 100 is provided with a microphone, but the microphone may be disposed independently of the muffler 100. For example, when the sound source is a human, the microphone may be a headset or the like worn by the human.

  Furthermore, as illustrated in FIG. 1, this active silencing system can also include a parent device 200 that mediates communication between the plurality of silencing devices 100-1, 100-2,. However, the silencers 100-1, 100-2,... May form a peer-to-peer network and communicate directly with each other. The communication is assumed to be wireless communication from the viewpoint of avoiding the complexity of wiring, but may be wired communication.

  In the active silencer system of FIG. 1, each silencer 100 detects information related to the position of the sound source, information related to the target position where the first sound wave from the sound source is silenced, and the like by its own sensor unit. The target position typically refers to a place where there is a third party who does not want to hear the first sound wave from the sound source. Further, the total number of target positions may be two or more. Based on various information detected by the sensor unit, the position of the sound source and the target position are calculated. Such position calculation may be performed intensively by the parent device 200, or may be performed individually by each silencer 100.

  Based on the calculated target position and the position of the sound source, the speaker unit and the microphone provided in each silencer 100 are set to an active state or an inactive state. In the example of FIG. 1, the speaker unit provided in the silencer 100-2 having the smallest distance from the target position among the silencers 100-1, 100-2,. The speaker units provided in the devices 100-1, 100-3, and 100-4 are set to an inactive state. Further, in the example of FIG. 1, the microphones installed in the silencer 100-1 having the smallest distance from the position of the sound source among the silencers 100-1, 100-2,. The microphones provided in the silencers 100-2, 100-3, and 100-4 are set in an inactive state.

  In this way, by setting a part of the microphone and the speaker unit to the active state and setting the remainder to the inactive state, it is possible to reduce power consumption in addition to suppressing howling. It should be noted that parent device 200 may centrally control the operation state of the microphone or speaker unit of each silencer 100, or each silencer 100 may individually control the operation state of its own microphone or speaker unit. Good.

  The microphone set to the active state receives the first sound wave from the sound source and converts it into an electric signal to obtain a first sound signal. The first audio signal is transmitted via the master unit 200 to the silencer 100-2 including the speaker unit set to the active state. If the microphone set to the active state is included in the same silencer 100 as the speaker unit set to the active state, the first audio signal may be transmitted inside the silencer 100.

  The silencer 100-2 receives the first audio signal and calculates a second audio signal based on the first audio signal. The calculation of the second audio signal may be performed by the silencer 100-1 or the parent device 200 that is the transmission source of the first audio signal.

  The speaker unit of the silencer 100-2 outputs the second sound wave by converting the second sound signal into physical vibration. The second sound wave has an effect of inhibiting the hearing of the first sound wave at the target position (for example, attenuating the amplitude). Therefore, according to this active silencing system, it is possible to make a person who is at the target position inaudible (or difficult to hear) a noise or a story that is not desired to be heard.

  As will be described later, the second sound signal may be appropriately calculated so that the second sound wave corresponds to the opposite phase wave of the first sound wave at the target position, or masking based on the first sound signal. It may correspond to sound.

  As illustrated in FIG. 2, the silencer 100 includes a wireless communication unit 101, a sensor unit 102, a microphone 103, a microphone control unit 104, a speaker unit 105, a speaker control unit 106, and an audio signal calculation unit. 107.

  The wireless communication unit 101 exchanges various information with the parent device 200. For example, the wireless communication unit 101 may receive various sensor information detected by the sensor unit 102 and transmit it to the parent device 200. The wireless communication unit 101 may receive the first audio signal acquired by the microphone 103 and transmit it to the parent device 200.

  Further, the wireless communication unit 101 may receive a parameter used for calculating an antiphase wave from the parent device 200 and pass it to the audio signal calculation unit 107. The wireless communication unit 101 may receive the first audio signal acquired by the microphone 103 provided in the other silencer 100 from the parent device 200 and pass it to the audio signal calculation unit 107. The wireless communication unit 101 may receive a control signal for controlling the operation state of the microphone 103 from the parent device 200 and pass it to the microphone control unit 104. The wireless communication unit 101 may receive a control signal for controlling the operation state of the speaker unit 105 from the parent device 200 and pass it to the speaker control unit 106.

  The sensor unit 102 can include, for example, an image sensor (for example, an infrared thermosensor), a distance sensor (for example, an ultrasonic wave or an infrared sensor), or the like. The sensor unit 102 detects information about the target position, information about the position of the sound source, information about the shape of the space around the silencer 100 (for example, an image obtained by photographing the periphery of the sensor unit 102), and the like.

  For example, the sensor unit 102 may detect direction information from the position of the silencer 100 including the sensor unit 102 to the position of the sound source or the target position. For example, an infrared thermosensor, which is a type of image sensor, can detect heat radiated from a human head with high sensitivity. Therefore, in the case where the person is a sound source or the case where the person is present is the target position, the direction information can be detected by using an infrared thermosensor. If the distance between the two silencers 100 is known, the position of the sound source or the target position can be calculated by performing triangulation using the direction information detected by the two silencers 100. .

  Further, the information of the first audio signal acquired by the microphone 103 may be used supplementarily or alternatively for the calculation of the position of the sound source. For example, the distance from the sound source can be estimated by utilizing the fact that the strength of the first audio signal is attenuated as the distance from the sound source is larger. Further, the distance from the sound source can also be estimated by utilizing the fact that the first sound wave arrives later as the distance from the sound source increases (that is, the first sound signal is acquired later).

  In addition, the position of each silencer 100 may be set manually at the time of installation, or relative relative relationship (for example, distance and direction) between the silencers 100 or between the silencer 100 and the parent device 200. It is also possible to calculate automatically based on this.

  For example, the silencer 100 may measure the distance to another silencer 100 or the parent device 200 using a distance sensor. Alternatively, after the master device 200 transmits a predetermined signal, the muffler 100 that has received this signal immediately returns a response, and based on the time required until the master device 200 receives this response, the master device 200. And the silencer 100 can be estimated. It is also possible to estimate the distance between the silencers 100 by a similar method. Furthermore, if an image sensor is mounted on the parent device 200, the direction information from the parent device 200 to each silencer 100 can be detected using this image sensor. Conversely, each silencer 100 may detect direction information from the silencer 100 to the parent device 200 using an image sensor included in the sensor unit 102.

  The operation state of the microphone 103 is set to an active state or an inactive state by the microphone control unit 104. When the microphone 103 is in an active state, the microphone 103 receives a sound wave propagating around it (particularly, a first sound wave output from a sound source) and converts it into an electric signal to generate a first sound signal. . The microphone 103 passes the first audio signal to the microphone control unit 104.

  The microphone control unit 104 controls the operation state of the microphone 103. The microphone control unit 104 may determine the operation state of the microphone 103 according to the control signal from the parent device 200, or may determine the operation state of the microphone 103 based on information on the position of the sound source detected by the sensor unit 102. May be. The microphone control unit 104 receives the first audio signal from the microphone 103 while the microphone 103 is set to the active state, and passes it to the wireless communication unit 101. When the speaker unit 105 is also in an active state in addition to the microphone 103, the microphone control unit 104 may pass the first audio signal to the audio signal calculation unit 107.

  The speaker unit 105 is set to an active state or an inactive state by the speaker control unit 106. When the speaker unit 105 is in the active state, the speaker unit 105 receives the second audio signal from the speaker control unit 106 and converts it into physical vibration to output a second sound wave. The speaker unit 105 may include a single speaker or a plurality of speakers.

  The speaker control unit 106 controls the operation state of the speaker unit 105. The speaker control unit 106 may determine the operation state of the speaker unit 105 according to a control signal from the parent device 200, or may determine the operation state of the microphone 103 based on information on the target position detected by the sensor unit 102. May be. The speaker control unit 106 receives the second audio signal from the audio signal calculation unit 107 and supplies the second audio signal to the speaker unit 105 while the speaker unit 105 is set to the active state.

  The audio signal calculation unit 107 receives the first audio signal from the wireless communication unit 101 or the microphone control unit 104. Furthermore, the audio signal calculation unit 107 may receive a parameter for calculating the second audio signal from the first audio signal from the wireless communication unit 101. The audio signal calculation unit 107 calculates a second audio signal corresponding to the second sound wave that inhibits the listening of the first sound wave at the target position, based on the first sound signal (and the parameter). The audio signal calculation unit 107 supplies the second audio signal to the speaker control unit 106.

  For example, the sound signal calculation unit 107 calculates the second sound signal based on the first sound signal and the parameter so that the second sound wave corresponds to the antiphase wave of the first sound wave at the target position. May be. If the second sound wave corresponding to the second sound signal is output, the component of the first sound wave is ideally canceled at the target position, and the person at the target position cannot hear it. Become.

  Or the audio | voice signal calculation part 107 may calculate the 2nd audio | voice signal corresponding to a masking sound based on a 1st audio | voice signal. For example, referring to Non-Patent Document 2, the audio signal calculation unit 107 can calculate the second audio signal corresponding to the masking sound as follows.

  The audio signal calculation unit 107 acquires the spectrum envelope of the first audio signal, and inverts the spectrum envelope up and down around the amplitude average, for example. Then, the audio signal calculation unit 107 calculates the second audio signal by adding the phase spectrum of the first audio signal to the inverted spectrum envelope and performing inverse Fourier transform. According to the second audio signal, the listening to the first sound wave can be inhibited at the target position even if the intensity is somewhat small.

  As illustrated in FIG. 3, the base unit 200 includes a wireless communication unit 201, a space shape calculation unit 202, an object characteristic calculation unit 203, a target position calculation unit 204, a sound source position calculation unit 205, and a propagation simulation. Part 206.

  The wireless communication unit 201 mediates communication between the silencers 100 (for example, transmission of the first audio signal). Further, the wireless communication unit 201 exchanges various information with each silencer 100. For example, the wireless communication unit 201 may receive information on the position of the sound source from the muffler 100 and pass it to the sound source position calculation unit 205. The wireless communication unit 201 may receive information about the target position from the muffler 100 and pass it to the target position calculation unit 204. The wireless communication unit 201 may receive information regarding the shape of the space around the silencer 100 from the silencer 100 and pass it to the space shape calculation unit 202.

  Also, the wireless communication unit 201 receives the parameter used for calculating the antiphase wave from the propagation simulation unit 206 and transmits the parameter to the muffler 100 (the speaker unit 105 is set to the active state). Good. The wireless communication unit 201 may transmit a control signal for controlling the operation state of the microphone 103 and the speaker unit 105 of each silencer 100 to the silencer 100.

  The space shape calculation unit 202 receives information on the shape of the space around the silencer 100 from the wireless communication unit 201 and calculates the shape of the space. The shape of the space is defined by a wall, a ceiling, a floor, and other objects that reflect the first sound wave and the second sound wave. The space shape calculation unit 202 passes information indicating the shape of the space to the object characteristic calculation unit 203 and the propagation simulation unit 206.

  The object characteristic calculation unit 203 receives information indicating the shape of the space from the space shape calculation unit 202, and the characteristics of various objects existing in the space (in particular, the object uses the first sound wave or the second sound wave). How it reflects). The object characteristic calculation unit 203 passes information indicating the characteristic of the object to the propagation simulation unit 206.

  The target position calculation unit 204 receives information regarding the target position from the wireless communication unit 201 and calculates the target position. The target position calculation unit 204 may calculate the target position using, for example, the method described above. The target position calculation unit 204 passes information indicating the target position to the propagation simulation unit 206. Note that the target position calculation unit 204 or other functional units (not shown) may control the operation state of the speaker unit 105 of each silencer 100 based on the target position.

  The sound source position calculation unit 205 receives information regarding the position of the sound source from the wireless communication unit 201 and calculates the position of the sound source. The sound source position calculation unit 205 may calculate the position of the sound source using, for example, the method described above. The sound source position calculation unit 205 passes information indicating the position of the sound source to the propagation simulation unit 206. Note that the sound source position calculation unit 205 or other functional units (not shown) may control the operation state of the microphone 103 of each silencer 100 based on the position of the sound source.

  The propagation simulation unit 206 receives information indicating the shape of the space from the space shape calculation unit 202, receives information indicating the characteristic of the object from the object characteristic calculation unit 203, receives information indicating the target position from the target position calculation unit 204, Information indicating the position of the sound source is received from the sound source position calculation unit 205. The propagation simulation unit 206 performs propagation simulation of sound waves in the space based on the received various information.

  For example, the propagation simulation unit 206 may simulate how to propagate to the target position and each microphone 103 when the first sound wave is output from the sound source. Further, the propagation simulation unit 206 may simulate how to propagate to the target position when the second sound wave is output from each speaker unit 105.

  The propagation simulation unit 206 creates parameters used for calculating the antiphase wave through the propagation simulation. Such parameters may include, for example, a transfer function from the sound source to the target position, a transfer function from the sound source to each microphone 103, a transfer function from each speaker unit 105 to the target position, and the like. The propagation simulation unit 206 passes the parameters to the wireless communication unit 201.

  The active silencer system of FIG. 1 can operate, for example, as shown in FIG. First, a plurality of silencers 100-1, 100-2,... And parent device 200 are installed around the sound source (step S301), and the process proceeds to step S302.

  In step S302, the space shape calculation unit 202 and the object property calculation unit 203 of the parent device 200 perform the shape of the space and the space in the space based on the sensor information collected from the silencers 100-1, 100-2,. Calculate the properties of the objects present in Further, the target position calculation unit 204 and the sound source position calculation unit 205 of the parent device 200 respectively set the target position and the position of the sound source based on the sensor information collected from the silencers 100-1, 100-2,. Calculate (step S303).

  Based on the information calculated in step S302 and step S303, the propagation simulation unit 206 of the parent device 200 performs a sound wave propagation simulation inside the space (step S304). In addition, the target position calculation unit 204 and the sound source position calculation unit 205 (or other functional units) of the parent device 200 perform the speaker unit 105 and the microphone of each silencer 100 based on the target position and the position of the sound source calculated in step S303. Each of the operation states 103 is controlled (step S305). This control suppresses howling.

  The wireless communication unit 201 of the base device 200 transmits the parameter created through the propagation simulation in step S306 to the silencer 100 including the speaker unit 105 set in the active state in step S305 (step S306). Thus, a series of operations in base unit 200 ends, and the process proceeds to step S307.

  In step S307, the microphone 103 set in the active state in step S305 receives the first sound wave from the sound source and generates a first sound signal. In the silencer 100 to which the parameter is transmitted in step S306, the audio signal calculation unit 107 calculates the second audio signal based on the parameter and the first audio signal generated in step S307 (step S308). . And the speaker part 105 contained in this silencer 100 outputs a 2nd sound wave (step S309).

  Basically, it is possible to continuously provide a silencing effect at the target position by repeatedly executing the processing from step S307 to step S309. However, when the target position or the position of the sound source changes greatly or an object in the space moves greatly, recalculation of parameters and reselection of the microphone 103 and the speaker unit 105 set to the active state are performed. It is desirable to do.

  Therefore, the sensor unit 102 of each silencer 100 detects the movement of surrounding persons and objects at a predetermined interval (for example, every second) (step S311). If the amount of movement detected in step S311 exceeds the threshold value, the process returns to step S302; otherwise, the process returns to step S307 (step S312).

  As described above, the active silencer system according to the first embodiment includes a plurality of silencers arranged around the sound source. The target position where the active silencing system provides the silencing effect is automatically calculated using information detected by the sensor unit provided in the silencer, and the speaker unit selected based on the target position is set to the active state. The And the speaker part set to the active state outputs the 2nd sound wave which inhibits the listening of the 1st sound wave from a sound source in a target position. In summary, this active silencing system can automatically calculate a target position and provide a silencing effect at the target position by arranging a plurality of silencers around the sound source. In other words, this active silencing system is easy to change because it is not subject to complicated installation conditions, and is suitable for carrying.

(Second Embodiment)
The active silencing system according to the first embodiment described above, for example, selects the speaker unit of one silencing device arranged closest to the target position and outputs the second sound wave, thereby reducing the silencing effect at the target position. Can be provided. However, since such a silencing effect is not intended to function at a point other than the target position, for example, it is difficult to sufficiently inhibit the moving person from hearing the first sound wave from the sound source. is there.

  Therefore, the active silencing system according to the second embodiment, for example, as shown in FIG. 5, selects the speaker units 105 of the plurality of silencing devices 100 in order from the target position and outputs the second sound waves, respectively. In this way, the area that provides the silencing effect is expanded.

  Further, as illustrated in FIG. 5, the active silencing system may select the microphones 103 of the plurality of silencers 100 in order from the position of the sound source and receive the first sound waves, respectively. By receiving the first sound wave using the plurality of microphones 103, the spread of the sound wave in the surrounding space can be more accurately evaluated.

  As described above, the active silencing system according to the second embodiment sets a plurality of speaker units selected based on the target position to the active state. And these speaker parts output individually the 2nd sound wave which obstructs listening of the 1st sound wave from a sound source in a target position. Therefore, this active silencing system can provide a silencing effect that is robust against displacement of the target position. That is, this active silencing system can continuously prevent the moving person from hearing the first sound wave from the sound source.

(Third embodiment)
As described above, the total number of target positions may be two or more. However, when a plurality of target positions are close to each other, the speaker unit selected to provide a silencing effect for the first target position may become a noise source when viewed from the second target position. is there.

  Therefore, the silencer 400 that forms the active silencer system according to the third embodiment includes the speaker unit 105 that can be used by switching a plurality of speakers having different directivities. Specifically, when the angle between the two target positions with respect to the speaker unit 105 is 70 degrees or less as a threshold value, the speaker unit 105 has a directivity angle of about 30 degrees as shown in FIG. Use directional speakers such as parametric speakers. On the other hand, when the angle exceeds 70 degrees, the speaker unit 105 uses a normal speaker (having a wider directivity angle). Note that a speaker with a wide directivity angle is highly likely to be a noise source viewed from other target positions, but there is a wide range in which a silencing effect can be provided. On the other hand, a speaker with a narrow directivity angle is unlikely to be a noise source when viewed from another target position, but has a narrow area that can provide a silencing effect.

  As described above, the active silencer system according to the third embodiment selects and uses a speaker having an appropriate directivity angle according to the relative positional relationship when there are a plurality of target positions. To do. Specifically, in this active silencing system, when two target positions are close to each other, a speaker unit that provides a silencing effect at one target position by using a speaker having a narrow directivity angle is provided on the other target position. It can be prevented that the noise source is viewed from the target position. In addition, when the two target positions are separated from each other, a silencing effect can be provided over a wide range by using a speaker having a wide directivity angle.

  The above problem can also be solved by configuring the speaker unit 105 with a speaker having a narrow directivity angle such as a parametric speaker instead of a normal speaker. According to such a technique, since switching of the speaker is not necessary, the processing load related to the control of the speaker unit can be reduced.

  The various functional units described in the above embodiments may be realized by using a circuit. The circuit may be a dedicated circuit that realizes a specific function, or may be a general-purpose circuit such as a processor.

  At least a part of the processing of each of the above embodiments can also be realized by using a general-purpose computer as basic hardware. A program for realizing the above processing may be provided by being stored in a computer-readable recording medium. The program is stored in the recording medium as an installable file or an executable file. Examples of the recording medium include a magnetic disk, an optical disk (CD-ROM, CD-R, DVD, etc.), a magneto-optical disk (MO, etc.), and a semiconductor memory. The recording medium may be any recording medium as long as it can store the program and can be read by the computer. The program for realizing the above processing may be stored on a computer (server) connected to a network such as the Internet and downloaded to the computer (client) via the network.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

100, 400 ... Silencer 101, 201 ... Wireless communication unit 102 ... Sensor unit 103 ... Microphone 104 ... Microphone control unit 105 ... Speaker unit 106 ... Speaker control unit 107 ..Audio signal calculation unit 200... Master 202... Space shape calculation unit 203... Object characteristic calculation unit 204... Target position calculation unit 205. Part

Claims (15)

At least one sensor for detecting information about the target position;
At least one microphone receiving a first sound wave output from a sound source and generating a first audio signal;
A plurality of speaker units,
At least one speaker unit selected based on the target position among the plurality of speaker units outputs a second sound wave that inhibits the first sound wave at the target position based on the first sound signal. To
Active silencing system.   The active silencer system according to claim 1, wherein a speaker unit having a minimum distance from the target position among the plurality of speaker units outputs the second sound wave. The sensor further detects information about the position of the sound source;
At least one of the microphones selected based on the position of the sound source receives the first sound wave;
The active silencing system according to claim 1.   The active silencing system according to claim 3, wherein a microphone having a minimum distance from a position of the sound source among the microphones receives the first sound wave. A plurality of communication units each connected to at least one of the plurality of speaker units and the microphone;
The communication unit connected to the microphone that receives the first sound wave transmits the first audio signal to the communication unit connected to the speaker unit that outputs the second sound wave.
The active silencing system according to claim 3. The sensor further detects information about the position of the sound source and information about the shape of the surrounding space;
The second sound signal input to at least one speaker unit selected based on the target position among the plurality of speaker units is such that the second sound wave has an opposite phase of the first sound wave at the target position. Calculated based on information on the target position, information on the position of the sound source, information on the shape of the space, and the first audio signal so as to correspond to a wave,
The active silencing system according to claim 1.   The second audio signal input to at least one speaker unit selected based on the target position among the plurality of speaker units corresponds to a masking sound based on the first audio signal. Active silencer system.   The plurality of speaker units selected based on the distance from the target position among the plurality of speaker units individually output the second sound wave based on the first audio signal. Active silencing system. A communication unit for receiving information on the target position from the sensor;
A base unit further comprising: a target position calculating unit that calculates the target position based on the information on the target position and selects a speaker unit that outputs the second sound wave based on the target position. The active silencing system according to 1. A target position calculation unit that calculates the target position based on information on the target position;
A sound source position calculation unit for calculating the position of the sound source based on information on the position of the sound source;
A space shape calculation unit for calculating the shape of the space based on information on the shape of the space;
An object characteristic calculator that calculates the characteristics of an object existing inside the space based on the shape of the space;
A speaker unit that outputs the second sound wave by performing a sound wave propagation simulation inside the space based on the target position, the position of the sound source, the shape of the space, and the characteristics of the object. A propagation simulation unit that creates a parameter used to calculate an input second audio signal; information about the target position; information about the position of the sound source; and information about the shape of the space; A communication unit that transmits the parameter to a silencer that includes a speaker unit that outputs the second sound wave;
Further comprising a master unit including
The silencer further includes an audio signal calculator that calculates the second audio signal based on the first audio signal and the parameter.
The active silencing system according to claim 6.   The active silencer system according to claim 1, wherein each of the plurality of speaker units includes a directional speaker. Each of the plurality of speaker units includes a first speaker and a second speaker having a narrower directivity angle than the first speaker,
The speaker unit that outputs the second sound wave is one of the first speaker and the second speaker according to a relative positional relationship between a target position corresponding to the speaker unit and another target position. To output the second sound wave,
The active silencing system according to claim 1.   The speaker unit that outputs the second sound wave selects the second speaker if an angle between the target position and the other target position is equal to or less than a threshold with respect to the speaker unit, and the angle is The active silencer system of claim 12, wherein the first speaker is selected if a threshold is exceeded. At least one sensor detects information about the target position; and at least one microphone receives a first sound wave output from the sound source and generates a first audio signal;
At least one speaker unit selected based on the target position among a plurality of speaker units outputs a second sound wave that inhibits the first sound wave at the target position based on the first sound signal. And
An active silencing method comprising: Means for causing at least one sensor to detect information relating to a target position;
Means for causing at least one microphone to receive a first sound wave output from a sound source and generate a first sound signal;
Output at least one of the plurality of speaker units to the speaker unit selected based on the target position, based on the first audio signal, the second sound wave that inhibits the first sound wave at the target position. An active silencer program that functions as a means to