Noise-canceling device and noise-canceling method

Abstract

The present invention provides a noise-canceling device and noise-canceling method that can appropriately cancel noise at an observation point even when the location of the observation point and sound source is uncertain. [Solution] The noise-canceling device 10 according to this embodiment includes: a sound source position identification unit 22 that identifies the position of a sound source from noise sounds collected by a plurality of microphones arranged around the sound source; a sound source sound pressure identification unit 23 that identifies the sound pressure of the sound source from the noise sounds; a distance calculation unit 26 that calculates the distance between a predetermined observation point and the sound source; an observation point sound pressure estimation unit 27 that estimates the sound pressure of the noise sounds heard at the observation point based on the calculated distance; and an audio output control unit 28 that outputs an out-of-phase sound that cancels out the noise sounds from a plurality of speakers arranged around the observation point, adjusted to the estimated sound pressure.

Description

Technical Field

[0001] The present invention relates to a noise canceling device and a noise canceling method.

Background Art

[0002] Generally, in order to suppress noise at a predetermined observation point, a noise canceling device that sends a noise canceling sound that cancels the noise generated by a sound source to the observation point is known. In Patent Document 1, a microphone that collects ambient sound as noise, a signal from the microphone is supplied, the signal from the microphone is made to have an opposite phase, and an amplitude level considering an attenuation amount according to the distance to an observation point away from the microphone A first signal generation unit that generates a noise canceling signal, a first speaker that is installed near the microphone and outputs a noise canceling signal, a second signal generation unit that is supplied with a signal from the microphone and generates a positive-phase signal that is in the same phase as the signal from the microphone, and a second speaker that is installed near the microphone and outputs a positive-phase signal, and the noise canceling signal output from the first speaker is attenuated by the positive-phase signal output from the second speaker, so that a noise canceling signal having an amplitude level equivalent to the noise canceling signal observed at the observation point reaches the microphone. A technology has been disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional configurations, the positions of the observation point and sound source are fixed. Therefore, if, for example, each user acting as the observation point and sound source can move within a predetermined closed space, and the positions of the observation point and sound source are undefined, it is difficult to properly cancel noise at the observation point, and there was room for improvement in this respect.

[0005] The present invention has been made in view of the above, and aims to provide a noise-canceling device and a noise-canceling method that can appropriately cancel noise at an observation point even when the positions of the observation point and sound source are uncertain. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the noise-canceling device according to the present invention comprises: a sound source positioning unit that identifies the position of a sound source from noise sounds collected by microphones placed around the sound source; a sound source sound pressure identification unit that identifies the sound pressure of the sound source from the noise sounds; a distance calculation unit that calculates the distance between a predetermined observation point and the sound source; an observation point sound pressure estimation unit that estimates the sound pressure of the noise sounds heard at the observation point based on the calculated distance; and an audio output control unit that outputs out-of-phase audio that cancels out the noise sounds from a plurality of speakers placed around the observation point, adjusted to the estimated sound pressure.

[0007] Furthermore, the noise cancellation method according to the present invention involves causing a computer to perform the following steps: identifying the location of a sound source from noise sounds collected by a plurality of microphones placed around the sound source; identifying the sound pressure of the sound source from the noise sounds; calculating the distance between a predetermined observation point and the sound source; estimating the sound pressure of the noise sounds heard at the observation point based on the calculated distance; and outputting an out-of-phase sound from speakers placed around the observation point, adjusted to the estimated sound pressure, to cancel out the noise sounds. [Effects of the Invention]

[0008] According to the present invention, even if the positions of the observation point and sound source are uncertain, noise at the observation point can be appropriately canceled. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram showing an example configuration of a noise-canceling device according to this embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the configuration of a space in which a noise-canceling device is used. [Figure 3] Figure 3 is a flowchart showing the operation procedure of the noise-canceling device. [Figure 4] Figure 4 is a schematic diagram showing an example of sound sources and observation points in each individual space. [Figure 5] Figure 5 illustrates an example of adjusting the output of each speaker according to its distance from the observation point. [Figure 6] Figure 6 is a schematic diagram showing another example of sound sources and observation points in each individual space. [Modes for carrying out the invention]

[0010] Figure 1 is a block diagram showing an example configuration of a noise-canceling device according to this embodiment. Figure 2 is a schematic diagram showing an example configuration of a space in which the noise-canceling device is used. The noise-canceling device 10 is installed in a predetermined space partitioned by walls and a ceiling, and cancels out noise (sound) emitted by one user (sound source) working in this space, thereby reducing the noise audible to other users (observation points) in this space. In this embodiment, noise refers to sounds including voices emitted by the user (sound source), such as speaking or coughing, or sounds generated when the user moves a desk or chair or performs work (actions). Each user moves freely within the space and works in one of several personal spaces pre-set within this space. Each personal space is virtually set up within the space and is not separated by physical walls or the like.

[0011] As shown in Figure 1, the noise-canceling device 10 comprises a microphone group 11, a speaker group 12, a seating sensor 13, and a control unit 20.

[0012] The microphone group 11 has multiple (e.g., 22) microphones M11 to M54 installed in a predetermined space 50. The speaker group 12 has multiple (e.g., 15) speakers S11 to S35 installed in this space 50. As shown in Figure 2, this space 50 is a closed space partitioned by first walls 51 to fourth walls 54 and a ceiling (not shown). In this example in Figure 2, the space 50 is a closed space that forms a rectangle in plan view, and the first wall 51 and the second wall 52 extend along a predetermined first axis (X axis). The third wall 53 and the fourth wall 54 extend along a second axis (Y axis) perpendicular to the first axis and are connected to the first wall 51 and the second wall 52, respectively.

[0013] Microphones M11-M54 and speakers S11-S35 are distributed and arranged within the aforementioned space 50. In the example in Figure 2, if the first axis is defined as rows and the second axis as columns, speakers S11-S35 are arranged in 3 columns x 5 rows, and microphones M11-M54 are arranged such that odd-numbered columns occupy 4 rows and even-numbered columns occupy 5 rows.

[0014] Specifically, the speakers S11 to S15 in the first column are arranged at equal intervals (predetermined intervals) along the first wall 51 (first axis direction). Here, speaker S11 in the first row is positioned at the corner between the first wall 51 and the third wall 53, and speaker S15 in the fifth row is positioned at the corner between the first wall 51 and the fourth wall 54. In addition, the speakers S31 to S35 in the third column are arranged at equal intervals along the second wall 52 (first axis direction). Speaker S31 in the first row is positioned at the corner between the second wall 52 and the third wall 53, and speaker S35 in the fifth row is positioned at the corner between the second wall 52 and the fourth wall 54. Furthermore, the speakers S21 to S25 in the second column are arranged at equal intervals midway between the first wall 51 and the second wall 52, along a direction parallel to either the first wall 51 or the second wall 52 (first axis direction). Thus, since each speaker in the same column and row is positioned on the same straight line, eight personal spaces (areas) PS1 to PS8 are formed within the space 50 by being surrounded by four adjacent speakers. In this embodiment, each speaker in each column is positioned at equal intervals, but if each speaker in the same row is positioned on the same straight line, the speaker spacing can be adjusted to appropriately change the size of the personal spaces PS1 to PS8.

[0015] These speakers S11 to S35 each have directionality, and for example, they can be formed by combining eight directional speakers (not shown) at 45° intervals in the circumferential direction. In this configuration, sound can be accurately output in a specific direction and noise can be properly canceled out. The number and arrangement angle of the directional speakers can be changed as appropriate; for example, a simple speaker can be formed by combining four directional speakers (not shown) at 90° intervals in the circumferential direction, or a high-precision speaker can be formed by combining 360 directional speakers (not shown) at 1° intervals in the circumferential direction.

[0016] Furthermore, microphones M11 to M54 are positioned so as not to interfere with speakers S11 to S35, and so as to surround the aforementioned personal spaces PS1 to PS8. Specifically, the first row of microphones M11 to M14 are positioned along the first wall 51 between the aforementioned speakers S11 to S15. In other words, the five speakers S11 to S15 and the four microphones M11 to M14 are arranged alternately along the first wall 51. The third row of microphones M31 to M34 are positioned between the aforementioned speakers S21 to S25. The fifth row of microphones M51 to M54 are positioned along the second wall 52 between the aforementioned speakers S31 to S35. Furthermore, microphones M21-M25 in the second row are positioned between microphones M11-M14 in the first row and microphones M31-M34 in the third row, at the same intervals as the speakers S11-S15 mentioned above. Microphones M41-M45 in the fourth row are positioned between microphones M31-M34 in the third row and microphones M51-M54 in the fifth row, at the same intervals as the speakers S11-S15 mentioned above.

[0017] These microphones M11 to M54 are directional; for example, the microphones arranged in odd-numbered rows have particularly high sensitivity from the direction along the second axis, while the microphones arranged in even-numbered rows have high sensitivity from the direction along the first axis. This configuration allows for the proper collection of noise generated in each individual space PS1 to PS8, enabling accurate identification of the noise source.

[0018] These individual spaces PS1 to PS8 refer to the areas used by the users respectively, and generally, it is assumed that operations such as desk work are carried out. In the individual spaces PS1 to PS8, four speakers and four microphones are provided so as to surround the individual spaces PS1 to PS8 respectively. In this configuration, the microphones surrounding each individual space collect the noise generated in that individual space, so that it is possible to identify where the single user (sound source) generating the noise (operation sound or transmission sound) is located in the individual spaces PS1 to PS8 (space 50). Also, in the individual spaces PS1 to PS8, a desk and a chair are arranged respectively, and the positions of the desks and chairs in these individual spaces PS1 to PS8 are fixed.

[0019] The seating sensor 13 is, for example, a pressure sensor provided on a chair or the like arranged in each of the individual spaces PS1 to PS8. When a user sits on the chair in the individual spaces PS1 to PS8, the seating sensor 13 detects it, and it is possible to identify where the user is located in the individual spaces PS1 to PS8 (space 50). Therefore, for example, when the seating sensor 13 detects seating in an individual space different from the individual space where the noise is generated, it can be identified that another user (observation point) different from the single user (sound source) is located in this different individual space.

[0020] The control unit 20 is, for example, an arithmetic processing device composed of a CPU (Central Processing Unit) or the like. As shown in FIG. 1, the control unit 20 includes an audio acquisition unit 21, a sound source position identification unit 22, a sound source sound pressure identification unit 23, a sensor information acquisition unit 24, an observation point position identification unit 25, a distance calculation unit 26, an observation point sound pressure estimation unit 27, and an audio output control unit 28, and they are respectively connected via a bus 29. The control unit 20 realizes these configurations and executes these processes by reading and executing a program stored in a storage unit (not shown). The control unit 20 may execute these processes by one CPU, or may include a plurality of CPUs and execute these processes in parallel by the plurality of CPUs.

[0021] The voice acquisition unit 21 acquires the voice (noise sound) collected by the microphone group 11. The voice acquisition unit 21 individually acquires the noise sounds collected by each of the microphones M11 to M54. The voice acquisition unit 21 outputs the acquired noise sounds to the sound source position identification unit 22 and the sound source sound pressure identification unit 23, respectively.

[0022] The sound source position identification unit 22 identifies the position of the sound source of the collected noise sound. The sound source position identification unit 22 identifies the position of the sound source (one user) from the noise sounds collected by a plurality of microphones arranged around the sound source. Specifically, the sound source position identification unit 22 uses at least three microphones arranged around, and calculates the distance difference between each microphone and the sound source based on the time difference at which the noise sound reaches each of these microphones, and identifies the position of the sound source from the positions of each microphone and the calculated distance differences (so-called trilateration method). For example, when a noise sound occurs in the personal space PS5, the position of the sound source is identified based on the data collected by at least three microphones selected from M31, M41, M42, and M51. The sound source position identification unit 22 outputs the identified position of the sound source to the sound source sound pressure identification unit 23 and the distance calculation unit 26.

[0023] The sound source sound pressure identification unit 23 identifies the sound pressure (dB) at the sound source of the collected noise sound. Since sound attenuates according to the distance from the sound source, it is common for the sound pressure to decrease. Therefore, the sound source sound pressure identification unit 23 identifies the sound pressure of the noise sound at the sound source position based on the sound pressures of the noise sounds collected by a plurality of (at least three used for sound source identification) microphones arranged around the sound source and the distances between each microphone and the sound source. Thereby, the sound pressure of the noise sound actually generated at the sound source position can be identified. The sound source sound pressure identification unit 23 outputs the sound pressure of the noise sound at the identified sound source position to the observation point sound pressure estimation unit 27.

[0024] The sensor information acquisition unit 24 acquires pre-set sensor information. In this embodiment, the sensor information acquisition unit 24 acquires seating information detected by the seating sensor 13 as sensor information. The sensor information acquisition unit 24 is not limited to seating information; for example, it may acquire photographic information taken by a camera (not shown) installed in the space 50, or audio information collected by microphones M11 to M54 as sensor information. The sensor information acquisition unit 24 outputs the acquired seating information (sensor information) to the observation point position identification unit 25.

[0025] The observation point location identification unit 25 identifies the location of the observation point based on sensor information. In this embodiment, the observation point location identification unit 25 identifies the location of the observation point (another user) based on seating information as sensor information. In this case, the observation point location identification unit 25 does not identify the location of the observation point when detecting seating information in the same personal space as the personal space from which the sound source was identified, because there is a high probability that it is the same user. The observation point location identification unit 25 outputs the identified location of the observation point to the distance calculation unit 26 and the observation point sound pressure estimation unit 27.

[0026] The distance calculation unit 26 calculates the distance between the identified observation point and the sound source. As described above, the position of the sound source and the position of the observation point are identified, so the straight-line distance between these observation points and the sound source is calculated. The distance calculation unit 26 outputs the calculated distance to the observation point sound pressure estimation unit 27.

[0027] The observation point sound pressure estimation unit 27 estimates the sound pressure of the noise sound heard at the observation point based on the calculated distance. In addition to the noise sound (speech) emitted from the sound source that reaches the observation point directly, some of it reaches indirectly after being reflected by the walls and ceiling of the space 50. The observation point sound pressure estimation unit 27 estimates the sound pressure of the noise sound heard at the observation point based on the calculated distance and the position of each wall.

[0028] The audio output control unit 28 outputs an out-of-phase sound from speakers arranged around the observation point, adjusting it to the estimated sound pressure to cancel out the noise. This out-of-phase sound is in phase with the wavelength of the target noise, and when these are combined, the noise is canceled out. The audio output control unit 28 adjusts the sound pressure of the out-of-phase sound output from each speaker according to the distance between the observation point and the multiple (e.g., four) speakers arranged around the observation point.

[0029] Next, the operation of the noise-canceling device 10 according to this embodiment will be described. Figure 3 is a flowchart showing the operation procedure of the noise-canceling device. Figure 4 is a schematic diagram showing an example of sound sources and observation points in each personal space. Figure 5 is a diagram illustrating an example of adjusting the output of each speaker according to the distance from the observation point.

[0030] The control unit 20 acquires noise sound from the microphone (step S1). More specifically, the control unit 20 acquires noise sound collected by any of the microphones M11 to M54 placed in the space 50 using the sound acquisition unit 21. In the example in Figure 4, noise sound emitted by a user A working in the personal space PS5 is acquired through four microphones M31, M41, M42, and M51 placed around the personal space PS5.

[0031] Next, the control unit 20 identifies the location of the noise source (step S2). The control unit 20 uses the sound source location identification unit 22 to identify the location of the noise source (user A) in the personal space PS5. The sound source location identification unit 22 uses at least three microphones from among microphones M31, M41, M42, and M51 to calculate the distance difference between each microphone and the sound source based on the time difference in which the noise reaches each microphone, and identifies the location of the sound source from the position of each microphone and the calculated distance differences.

[0032] Next, the control unit 20 identifies the sound pressure of the noise at the sound source location (step S3). The control unit 20 uses a sound source sound pressure identification unit 23 to identify the sound pressure of the noise at the sound source from the collected noise. The sound source sound pressure identification unit 23 identifies the sound pressure of the noise at the sound source location based on the respective sound pressures of the noise collected by microphones M31, M41, M42, and M51, and the respective distances between microphones M31, M41, M42, and M51 and the sound source (user A).

[0033] Next, the control unit 20 determines whether or not there is any detection from the seating sensor 13 (step S4). In this determination, if there is no detection from the seating sensor 13 (step S4; No), it is determined that there are no users affected by the noise sound, and the process ends there. On the other hand, if there is detection from the seating sensor 13 (step S4; Yes), the control unit 20 identifies the location of the observation point based on the detection result of the seating sensor 13 (step S5). Specifically, the control unit 20 uses the observation point location identification unit 25 to identify where the user who is the observation point is located in the space 50 (personal space PS1 to PS8) based on the detection result of the seating sensor 13. In this case, in order to prevent detection of the same user, it is preferable that the observation point location identification unit 25 identifies the location of the observation point when there is detection from the seating sensor 13 in a personal space different from personal space PS5 where the sound source (user A) has been identified. In the example in Figure 4, it is assumed that the observation point (another user B) has been identified as being in personal space PS3, which is different from personal space PS5.

[0034] Next, the control unit 20 calculates the distance between the sound source and the observation point (step S6). The control unit 20 calculates the distance between the identified observation point and the sound source using the distance calculation unit 26. The distance calculation unit 26 calculates the straight-line distance between these observation points and the sound source based on the identified positions of the sound source and the observation points.

[0035] Next, the control unit 20 estimates the sound pressure of the noise heard at the observation point based on the calculated distance (step S7). The noise emitted from the sound source includes both noise that reaches the observation point directly and noise that reaches it indirectly after being reflected by the walls and ceiling of the space 50. The control unit 20 estimates the sound pressure of the noise heard at the observation point based on the calculated distance and the positional relationship of the walls and ceiling of the space 50, using the observation point sound pressure estimation unit 27.

[0036] Finally, the control unit 20 outputs audio from speakers around the observation point that is in the opposite phase to the noise sound, adjusted to the estimated sound pressure (step S8). The control unit 20, using the audio output control unit 28, adjusts the sound pressure of the inverse-phase audio output from each speaker S13, S14, S23, S24, which are arranged around the personal space PS3 where the observation point (user B) is located, according to the distance between the speakers S13, S14, S23, S24 and the observation point (user B). In this embodiment, the distance between each speaker S13, S14, S23, S24 and the observation point (user B) is calculated, and the sound pressure is adjusted so that it is higher the closer the distance. It was found that this configuration is highly effective in canceling out the noise sound at the observation point when audio that is in the opposite phase to the noise sound is output from multiple speakers.

[0037] In this case, the audio output control unit 28 adjusts the output of each speaker S13, S14, S23, and S24 using a complement of the distance ratio such that it is larger the closer the speaker S13, S14, S23, and S24 are to the observation point (user B), and smaller the farther they are. Specifically, the audio output control unit 28 calculates the complement of the positional ratio between the target speaker and the observation point for the first direction (X direction) and the second direction (Y direction) in relation to the positional relationship between the multiple (two) speakers whose output is to be adjusted and the observation point between these speakers, and can calculate the final output of the target speaker by multiplying this complement by the original output.

[0038] Let's explain using the example in Figure 5. Figure 5 shows an example of a personal space PS3, with speakers S13, S14, S23, and S24 positioned at the corners of the square-shaped personal space PS3. In Figure 5, the audio output control unit 28 calculates the complement of the positional ratio between speakers S23, S24 (or speakers S13, S14) and the observation point (user B) in the first direction (X direction). In this case, the complement of the positional ratio between speaker S23 (or speaker S13) and the observation point (user B), X1, is 30%, and the complement of the positional ratio between speaker S24 (or speaker S14) and the observation point (user B), X2, is 70%. The audio output control unit 28 also calculates the complement of the positional ratio between speakers S23, S13 (or speakers S24, S14) and the observation point (user B) in the second direction (Y direction). In this case, the complement Y1 of the positional ratio between speaker S23 (or speaker S24) and the observation point (user B) is 60%, and the complement Y2 of the positional ratio between speaker S13 (or speaker S14) and the observation point (user B) is 40%.

[0039] If we denote the speaker output corresponding to the sound pressure of the out-of-phase sound described above as OP, the final outputs of each speaker S13, S14, S23, and S24 are calculated as follows.

[0040] The final output of speaker S23 = OP*X1*Y1 = OP*0.3*0.6 = 0.18 OP, the final output of speaker S24 = OP*X2*Y1 = OP*0.7*0.6 = 0.42 OP, the final output of speaker S13 = OP*X1*Y2 = OP*0.3*0.4 = 0.12 OP, and the final output of speaker S14 = OP*X2*Y2 = OP*0.7*0.4 = 0.28 OP.

[0041] Thus, the final output of each speaker increases in the order of speaker S24 > speaker S14 > speaker S23 > speaker S13, with the closer the speaker is to the observation point (user B). By adjusting the final output of each speaker according to the distance from the observation point (user B), the noise sound at the observation point can be more effectively canceled out. Note that the OP mentioned above refers to the output of a sound that is inverse phase to the noise sound heard at the observation point (i.e., the 100% value without being multiplied by the correction coefficient).

[0042] Next, a modified example will be described. Figure 6 is a schematic diagram showing another example of sound sources and observation points in each individual space. In Figure 6, the observation point (user B) is located close to the first wall 51. When the observation point (user B) is close to a wall (for example, the first wall 51), the out-of-phase sound output from the speaker is reflected by the first wall 51, and this reflected sound can hinder the effect of canceling out noise. For this reason, the sound output control unit 28 prioritizes the use of speakers that produce less reflected sound in order to suppress the effect of reflected sound. That is, the sound output control unit 28 controls the output of speakers S23 and S24 located further away from the first wall 51 to be higher than that of speakers S13 and S14 located closer to the first wall 51. Specifically, the audio output control unit 28 controls the output of speakers S23 and S24 located further from the first wall 51 to a predetermined multiple (e.g., 1.1 to 1.5 times) of the output of speakers S13 and S14 located closer to the first wall 51, when the observation point (user B) is within a predetermined distance (e.g., 1 m) from the first wall 51. This configuration effectively cancels out noise by suppressing the effects of reflected sound.

[0043] As described above, the noise-canceling device 10 according to this embodiment includes a sound source positioning unit 22 that identifies the position of a sound source from noise sounds collected by a plurality of microphones M31, M41, M42, M51 arranged around a user A as a sound source; a sound source sound pressure identification unit 23 that identifies the sound pressure of the sound source from the noise sounds; a distance calculation unit 26 that calculates the distance between the sound source and another user B as a predetermined observation point; an observation point sound pressure estimation unit 27 that estimates the sound pressure of the noise sounds heard at the observation point based on the calculated distance; and an audio output control unit 28 that outputs out-of-phase audio that cancels out the noise sounds from a plurality of speakers S13, S14, S23, S24 arranged around the observation point, adjusted to the estimated sound pressure. Therefore, even if the positions of the observation point and the sound source are uncertain, the noise sounds at the observation point can be appropriately canceled.

[0044] In the noise-canceling device 10 according to this embodiment, four microphones M31, M41, M42, and M51 are arranged around the sound source, and the sound source sound pressure identification unit 23 identifies the sound pressure at the location of the sound source based on the noise sound collected by each microphone M31, M41, M42, and M51, thus enabling accurate identification of the sound pressure of a sound source at an unspecified location.

[0045] Furthermore, in the noise-canceling device 10 according to this embodiment, four speakers S13, S14, S23, and S24 are arranged around the observation point, and the audio output control unit 28 adjusts the sound pressure of the out-of-phase audio output from the speakers S13, S14, S23, and S24 according to the distance between the observation point and the speakers S13, S14, S23, and S24, thereby enabling more appropriate cancellation of noise at the observation point.

[0046] Furthermore, in the noise-canceling device 10 according to this embodiment, a predetermined closed space 50 is divided into multiple personal spaces PS1 to PS8, and four microphones and four speakers are arranged for each personal space PS1 to PS8 so as to surround each personal space PS1 to PS8. Therefore, even if the user, acting as both the sound source and the observation point, moves between personal spaces PS1 to PS8 and the positions of the observation point and sound source are not fixed, noise at the observation point can be appropriately canceled.

[0047] Although embodiments of the present invention have been described above, the embodiments are not limited to those described herein. Furthermore, the aforementioned components include those that can be easily conceived by those skilled in the art, those that are substantially the same, and those that fall within the so-called equivalent range. Moreover, the aforementioned components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above.

[0048] Furthermore, each component of the control unit 20 in this embodiment is a functional concept and does not necessarily have to be physically configured as shown in the illustration. In other words, the specific form of each device is not limited to that shown in the illustration, and all or part of them may be functionally or physically distributed or integrated in any unit depending on the processing load and usage of each device. The configuration of the control unit 20 is realized, for example, as software, such as a program loaded into memory. In the above embodiment, these were described as functional blocks realized by the cooperation of hardware or software. In other words, these functional blocks can be realized in various forms by hardware alone, software alone, or a combination thereof.

[0049] Furthermore, although this embodiment describes a configuration in which there is one sound source (one user A) and one observation point (another user B) within space 50, there may be multiple sound sources and observation points. [Explanation of Symbols]

[0050] 10. Noise-canceling devices 11 microphone groups 12 speaker groups 13. Seat sensor 20 Control Unit 21. Voice acquisition unit 22 Sound source location identification section 23 Sound source sound pressure determination unit 24 Sensor Information Acquisition Unit 25 Observation point location identification unit 26 Distance Calculation Unit 27. Sound pressure estimation unit at observation points 28 Audio Output Control Unit 50 space M11, M12, M13, M14, M21, M22, M23, M24, M25, M31, M32, M33, M34, M41, M42, M43, M44, M45, M51, M52, M53, M54 Microphone S11, S12, S13, S14, S15, S21, S22, S23, S24, S25, S31, S32, S33, S34, S35 Speakers PS1, PS2, PS3, PS4, PS5, PS6, PS7, PS8 Personal Space A. One user (sound source) B Other users (observation points)

Claims

1. A sound source location identification unit identifies the location of the sound source from noise sounds collected by microphones placed around the sound source, A sound source sound pressure identification unit that identifies the sound pressure of the sound source from the noise sound, A distance calculation unit that calculates the distance between a predetermined observation point and the sound source, An observation point sound pressure estimation unit estimates the sound pressure of the noise sound heard at the observation point based on the calculated distance, A noise-canceling device comprising: an audio output control unit that outputs an out-of-phase sound from a plurality of speakers arranged around the observation point, adjusting it to the estimated sound pressure to cancel out the noise sound.

2. At least three of the aforementioned microphones are arranged around the sound source. The noise-canceling device according to claim 1, wherein the sound source sound pressure identification unit identifies the sound pressure at the location of the sound source based on the noise sound collected by each microphone.

3. At least three of the aforementioned speakers are arranged around the observation point. The noise-canceling device according to claim 1 or 2, wherein the audio output control unit adjusts the sound pressure of the audio output from the speaker according to the respective distances between the observation point and the speaker.

4. The noise-canceling device according to claim 1, wherein a predetermined closed space is divided into multiple areas, and at least three microphones and at least three speakers are arranged in each area so as to surround each area.

5. The steps include identifying the location of the sound source from noise sounds collected by multiple microphones placed around the sound source, A step of determining the sound pressure of the sound source from the noise sound, A step of calculating the distance between a predetermined observation point and the sound source, A step of estimating the sound pressure of the noise sound heard at the observation point based on the calculated distance, The steps include: outputting an out-of-phase sound from speakers arranged around the observation point, adjusting it to the estimated sound pressure, to cancel out the noise sound; A noise cancellation method that is performed by a computer.

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