JP2019066601A - Acoustic processing device, program and method - Google Patents

Abstract

To provide an acoustic processing device without reducing masking effect for the sound to be listened by a listener to surrounding people located in the surroundings while reducing the restriction on an installation environment of a speaker.SOLUTION: An acoustic signal processing device 10 which generates an acoustic signal supplied to a speaker includes: stereophonic acoustic masking sound holding means for holding a stereophonic acoustic masking sound subjected to stereophonic acoustic processing which localizes the masking sound for masking an input sound to be listened by a listener from the speaker to a place different from the place where the input sound can be heard by the listener; mixing means for performing mixing processing for mixing the stereophonic acoustic masking sound and the input sound so as to generate a mixed sound; and output means for outputting an acoustic signal of the mixed sound mixed by the mixing means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an audio processing apparatus, program, and method, and can be applied to speech privacy in three-dimensionally reproducing an audio signal from a speaker.

  Currently, in places where security information and privacy are important in public spaces and stores (for example, administrative agencies, financial institutions, medical facilities, etc.), speech privacy is required so that the contents of conversations can not be heard by a third party. ing.

  As a conventional technology related to speech privacy, there are the technologies described in Patent Documents 1 and 2.

  Patent Document 1 proposes a device that makes it difficult for a person behind the user to hear by masking a conversation using a speaker that reproduces a masking sound. Further, according to Patent Document 2, when the position of the speaker and the position of the speaker for reproducing the masking sound are separated, the stereo speaker is used for the problem of being heard from the position of the sound source. We have proposed a device where you can hear the masking sound in front of you. Conventionally, there is also an example in which an apparatus for realizing the speech privacy as described above is used in an actual store.

JP, 2012-137742, A JP 2007-235864 A JP, 2013-183358, A

  By the way, nowadays, with the development of information and communication technology (ICT), not only face-to-face communication but also hands-free communication with a remote place through a terminal is often performed. And now there is a growing demand for speech privacy in hands-free calling situations.

  For example, in a situation where a customer receives various services by hands-free calling at a store etc., it is assumed that the customer is at the store etc and the corresponding staff is at a remote place such as a call center. In this case, the voice of the customer (near end sound) is picked up by the microphone of the terminal, and the voice of the staff (far end sound) is reproduced from the speaker of the terminal. However, the following problems can not be solved with a hands-free device (hereinafter referred to as a "speech privacy device") compatible with conventional speech privacy. First, in order to be effective by the speech privacy device, the volume of the speaker must be below a certain value with respect to the masking volume. For example, when a customer talks with a clerk in a face-to-face manner, the noise and masking sound of the place can be heard directly, so the speaker can control his own volume according to the situation. However, in the case of the conventional speech privacy apparatus, the far-end speaker (for example, a clerk at a remote place) controls his own volume because he does not know the situation of the near-end speaker (for example, the customer at the store). It may not be possible and near-end may not be able to achieve sufficient speech privacy effects. For example, in the conventional speech privacy apparatus, if the masking volume is set large in consideration of the case where the far-end sound is large, the masking sound itself may disturb both the near-end sound and the far-end sound.

  Further, in both of the conventional speech privacy devices described in Patent Documents 1 and 2, the speaker outputting the voice of the far-end speaker is located behind the position of the near-end speaker (as opposed to the speaker as seen from the near-end speaker Needs to be installed on the In the conventional speech privacy apparatus, if the speaker is placed before the customer, the far-end sound itself is masked by the masking sound of the speech privacy apparatus. Therefore, in the conventional speech privacy apparatus, it is necessary to secure a space for installing a speaker on the rear side of the near-end speaker, and the environment in which the speech privacy apparatus can be used is limited.

  Furthermore, both of the conventional speech privacy devices described in Patent Documents 1 and 2 place the speaker behind the near-end speaker, so the speaker can be used for people located behind the near-end speaker. The voice of the speaker becomes difficult to hear, but the effect diminishes for those who are in the lateral direction of the near-end speaker (the lateral direction as viewed from the near-end speaker facing the speaker). Therefore, the conventional speech privacy apparatus can not cope with a situation where terminals used by customers (near end speakers) such as a ticket vending machine or an ATM are arranged in a horizontal row, for example.

  In view of the problems as described above, while relaxing the restriction on the installation environment of the speaker, for those who are located in the surroundings (hereinafter referred to as "neighbors") the sound that the listener (near end speaker) listens to There is a need for an audio processing device, program and method that does not reduce the masking effect.

  According to a first aspect of the present invention, there is provided an acoustic signal processing apparatus for generating an acoustic signal to be supplied to a speaker, wherein (1) a masking sound for masking an input sound for causing a listener to listen from the speaker is Stereophonic sound masking sound holding means holding stereophonic sound masking sound subjected to stereophonic sound processing localized to a place different from the place where the input sound can be heard; (2) mixing that mixes the stereophonic sound masking sound with the input sound It is characterized by having a mixing means for processing to generate a mixed sound, and (3) an output means for outputting an acoustic signal of the mixed sound mixed by the mixing means.

  According to a second aspect of the present invention, there is provided an acoustic signal processing program for masking an input sound for causing a listener to listen to a computer mounted on an acoustic signal processing apparatus that generates an acoustic signal to be supplied to a speaker. Stereophonic sound masking sound holding means for holding a stereophonic sound masking sound subjected to stereophonic sound processing localized to a place different from the place where the input sound can be heard by the listener with respect to the masking sound of (2) the stereophonic sound masking It is characterized in that it functions as mixing means for mixing processing for mixing sound and the input sound to generate mixed sound, and (3) output means for outputting an acoustic signal of the mixed sound mixed by the mixing means.

  A third aspect of the present invention is an acoustic signal processing method performed by an acoustic signal processing apparatus for generating an acoustic signal to be supplied to a speaker, the method comprising: (1) three-dimensional acoustic masking sound holding means, mixing means, and output means The stereophonic sound masking sound holding means localizes the masking sound for masking the input sound to be listened to by the listener from the speaker to a place different from the place where the input sound can be heard by the listener (3) the mixing means performs mixing processing for mixing the three-dimensional acoustic masking sound and the input sound to generate a mixed sound, and (4) the output means includes: The mixing means may output an acoustic signal of the mixed sound mixed.

  According to the present invention, it is possible to provide a sound processing device that does not reduce the effect of masking the sound to be heard by the listener against the surrounding people while relaxing the restriction of the installation environment of the speaker.

It is a block diagram showing functional composition of an acoustic signal processing device concerning a 1st embodiment. It is explanatory drawing shown about how the sound of the user (the listener who exists in a sweet spot) of the acoustic signal processing apparatus concerning 1st Embodiment is audible. It is explanatory drawing shown how sound of persons other than the user of the acoustic signal processing apparatus concerning 1st Embodiment (person outside a sweet spot) is heard. It is explanatory drawing shown about the environment model at the time of performing transaural reproduction | regeneration by the acoustic signal processing apparatus which concerns on 1st Embodiment (state which crosstalk generate | occur | produces at the time of speaker use). It is a block diagram which shows the structure of the acoustic signal processing apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the acoustic signal processing apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the acoustic signal processing apparatus which concerns on 4th Embodiment.

(A) First Embodiment Hereinafter, a first embodiment of a sound processing device, program and method according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of First Embodiment FIG. 1 is a block diagram showing an overall configuration of an acoustic signal processing device 10 according to a first embodiment.

  The sound signal processing device 10 is a device that processes and outputs an input sound I (sound signal of input sound). In this embodiment, the acoustic signal processing apparatus 10 outputs an acoustic signal to the stereo speaker Sp. The stereo speaker Sp is configured of a left speaker SpL and a right speaker SpR.

  Further, the acoustic signal processing apparatus 10 masks the input sound I against persons other than the user U who is the target (listener) who is made to listen to the input sound I (hereinafter referred to as “peripheral”) In response to the supply of the masking sound M, the masking sound M is subjected to three-dimensional acoustic processing to generate an acoustic signal mixed with the input sound I and output to the speakers SpL and SpR. In this embodiment, an example in which the sound signal processing apparatus 10 outputs to a stereo speaker configured by two speakers has been described, but the configuration of the speaker to output (for example, the number and positions of the speakers) is not limited. It is a thing.

  The use environment (application) of the acoustic signal processing device 10 is not limited. In the example of this embodiment, the input sound I is the sound on the far end side in hands-free communication (hereinafter, referred to as “far end sound”) (for example, the sound captured by the far end microphone). The acoustic signal processing apparatus 10 is described as outputting the sound based on the input sound I from the stereo speaker SP (left speaker SpL, right speaker SpR) and causing the user U on the near end to listen. Note that in an actual hands-free call, it is necessary to have a configuration for capturing a sound (hereinafter, referred to as a “near end sound”) including a voice uttered by the near end user U and transmitting it to the far end. The communication configuration from the near end side to the far end side is not limited, and is not shown in FIG. The sound signal processing device 10 may be a device that processes a recorded voice (for example, voice guidance for the user U) as the input sound I other than the hands-free call.

  FIG. 1 shows an example in which the positional relationship between the user U who is the target of listening to the input sound signal I and the speakers SpL and SpR constituting the stereo speaker SP is viewed from the upper side. In FIG. 1, the position of the user U (the center position of the head when viewed from the top) is PU, the position of the left speaker SpL (the center position when viewed from the top) is PL, the position of the right speaker SpR (from the top The central position when viewed is shown as PR. In FIG. 1, the speakers SpL and SpR are disposed on the front side when viewed from the user U.

  Further, in FIG. 1, the area AS is a sweet spot of stereo sound processing performed in the sound signal processing apparatus 10 (an area where a sound image can be localized for a listener as designed). Then, the user U is located in the area AS.

  Next, the internal configuration of the acoustic signal processing device 10 will be described.

  As shown in FIG. 1, the acoustic signal processing apparatus 10 includes an input sound signal input unit 12, a masking sound signal input unit 11, a three-dimensional sound processing unit 13, a signal mixing unit 14, and a speaker output unit 15. Details of each component of the acoustic signal processing device 10 will be described later.

  The acoustic signal processing apparatus 10 may be realized by causing a computer including a processor, a memory, and the like to execute a program (including the acoustic reproduction program according to the embodiment), but even in such a case, functional Can be represented as shown in FIG.

(A-2) Operation of First Embodiment Next, an operation (sound reproduction method according to the embodiment) of the acoustic signal processing device 10 in the first embodiment having the above-described configuration will be described.

  When the input sound I (analog acoustic signal) is supplied, the input sound signal input unit 12 converts the input I from an analog signal to a digital signal.

  Further, when the masking sound M (analog acoustic signal) is input, the masking sound signal input unit 11 converts the masking sound M from an analog signal to a digital signal.

  If the masking sound M includes a component capable of masking the input sound I (far end sound) reproduced from the stereo speaker Sp or the voice (near end sound) uttered by the user U, specific content Is not limited. As the masking sound M, for example, an audio sample uttered by a human may be used as it is or as an processed acoustic signal.

  The input format of the input sound I and the masking sound M in the acoustic signal processing apparatus 10 is not limited to the above-described configuration, and various configurations can be applied. For example, the input sound I and masking sound M in digital format may be input to the audio signal processing apparatus 10, or may be input collectively as audio data in file format instead of stream format.

  For the masking sound M, the user can make the masking sound M heard from a place other than the speaker SpR or SpL (that is, a place different from the place where the input sound I is to be localized). Perform stereophonic sound processing to localize the sound image. In the three-dimensional sound processing unit 13, a masking sound processed by three-dimensional sound processing of the masking sound M (hereinafter also referred to as "three-dimensional sound masking sound") is simultaneously set in plural (three-dimensional sound masking sound based on the same masking sound M). The stereophonic sound processing is performed so that each stereophonic sound masking sound is localized in different directions with respect to the user.

  Next, a specific example of stereophonic sound processing (setting of stereophonic sound masking sound) in the stereophonic sound processing unit 13 will be described using FIG.

  In FIG. 2, the direction of 90 degrees left with respect to the user U facing the direction F of the midpoint of the line connecting the positions of the two speakers SpL and SpR PL and PR located in the sweet spot AS ( The first stereophonic sound masking sound MS1 positioned at 90 degrees counterclockwise with 0 degrees as the direction of F, and clockwise 90 degrees right with respect to the user U (the direction of F as 0 degrees It is illustrated about the state where the 2nd three-dimensional sound masking sound MS2 located in the direction of 90 degrees is set. Further, in this embodiment, since the input sound I is not particularly subjected to three-dimensional sound processing, in FIG. 2, the input sound I is localized between two speakers (the space between the positions PL and PR) and State is shown. Although this embodiment shows an example in which the input sound I is not particularly subjected to the stereophonic sound processing, the stereophonic sound localized in a predetermined direction (for example, a direction in which the user U is assumed to be directed) is also performed on the input sound I. Processing may be performed. For example, in order to realize the state as shown in FIG. 2, the three-dimensional sound processing unit 13 is based on the masking sound M in one or more directions with respect to the user U (different from where the input sound I is localized 3D acoustic masking sound generated by performing stereophonic sound processing to localize the masking sound M with respect to the direction).

The method of stereophonic sound processing performed by the stereophonic sound processing unit 13 is not limited, but, for example, a technique of transaural reproduction as described in the following reference 1 may be applied. Transaural reproduction is a technology in which the same three-dimensional sound effect as binaural reproduction, which is a three-dimensional sound technology using earphones and headphones, is applied to a speaker.
[Reference 1] WG Gardner, "3-D Audio Using Loudspeakers", Springer (US), published in 1977

  In binaural reproduction, a three-dimensional sound effect can be generated by convoluting a head-related transfer function in a direction desired to be localized to an acoustic signal as a sound source, converting it into a binaural sound source, and reproducing it from headphones or earphones.

  FIG. 4 is an explanatory view showing an environment model when the stereophonic sound processing unit 13 performs stereophonic sound processing using the technique of transaural reproduction.

In FIG. 4, the code of the right ear of the user U is illustrated as e _R and the code of the left ear of the user U is illustrated as e _L.

For example, if a binaural sound source is reproduced as it is from the speakers SpL and SpR, it is impossible to obtain a sufficient three-dimensional sound effect. For example, the binaural sound source for the right ear needs to reach only the right ear e _R of the user U, but the binaural sound source for the right ear reproduced from the right speaker SpR is not only the right ear e _R but also the left ear e _L Will reach you. Similarly, the binaural sound source for the left ear reproduced from the left speaker SpL also reaches not only the left ear e _L but also the right ear e _R. Such a phenomenon is called crosstalk, which is a cause of obstructing a stereophonic sound effect when the speaker is used as a reproduction environment.

  On the other hand, in transaural reproduction described in reference 1, after measuring the room transfer function from each speaker to both ears, the transfer function is convoluted with the binaural sound source, and only the crosstalk component in that is canceled. Design a filter.

In Figure 4, the transfer function of the right speaker right ear path transfer function G _RR of (path from the right speaker SpR to the right ear e _R), (path from the right speaker SpR to the left ear e _L) right speaker left ear path G _RL , Transfer function of left speaker right ear path (path from left speaker SpL to right ear e _R ) G _LR , Transfer function of left speaker left ear path (path from left speaker SpL to left ear e _L ) _Is illustrated as _GLL .

Also, in the following, the filter for the left speaker left ear path in transaural reproduction is C _LL (ω) (“ω” represents a frequency. The same applies hereinafter), the filter for the right speaker right ear path is C _RR (ω), left The filter of the speaker right ear path is C _LR (ω), the filter of the right speaker left ear path is C _RL (ω), and the filter of the left speaker left ear path is C _LL (ω). Furthermore, in the following, a head-related transfer function (HRTF) corresponding to the sound source localization position for the left ear is H _L (ω), and a head-related transfer function corresponding to the sound source localization position for the left ear _Let (HRTF) be H _R (ω).

Then, the filters of each path in transaural reproduction can be expressed as the following equations (1) to (4). Then, assuming that G ₀ (ω) is a sum of common terms (that is, common terms of each filter) of the equations (1) to (4), G ₀ (ω) is given by the following equation (5) Can be shown.

Then, when the filters of each path shown in the above equations (1) to (4) are summarized for each of the left and right speakers SpL and SpR, as shown in the equations (6) and (7), cross in transaural reproduction It is possible to obtain a crosstalk cancellation filter used to suppress the talk. C _R (ω) shown in the equation (6) is a crosstalk cancellation filter for the right speaker SpR, and C _L (ω) shown in the equation (7) is a crosstalk cancellation filter for the left speaker SpL.

  In the transaural reproduction, the crosstalk cancellation filter as described above is applied to the sound source (the masking sound M in this embodiment) for sound image localization, and the crosstalk component is reproduced for each listener (user U). It is canceled at the ear, and only the left and right binaural sound sources reach the ear, and a stereophonic effect similar to binaural reproduction can be obtained.

Therefore, based on the masking sound M, as shown in FIG. 2, the three-dimensional sound processing unit 13 localizes the first three-dimensional sound masking sound MS1 (direction D1) and the second three-dimensional sound masking sound MS2 (direction D2) When performing processing of transaural reproduction to be performed, first, a first binaural sound source in which the first three-dimensional sound masking sound MS1 is set and a binaural sound source in which the second three-dimensional sound masking sound MS2 is set are generated. Then, the three-dimensional sound processing unit 13 applies a crosstalk cancellation filter C _R (ω) for the right speaker SpR to the binaural sound source for the right ear (for the right speaker SpR) to generate an acoustic signal for transaural reproduction for the right speaker SpR. (Sound source) is generated, the crosstalk cancellation filter C _L (ω) for the left speaker SpL is applied to the binaural sound source for the left ear (for the left speaker SpL), and the acoustic signal for the transaural reproduction for the left speaker SpL (sound source Process to generate).

  Hereinafter, the acoustic signal processed by the three-dimensional acoustic processing unit 13 (the acoustic signal of the three-dimensional acoustic masking sound) will be referred to as X. Here, since the reproduction environment of the acoustic signal processing apparatus 10 is the stereo speaker Sp (speakers SpL and SpR), the acoustic signal X includes an acoustic signal for the right speaker SpR (hereinafter referred to as “XR”); An acoustic signal (hereinafter referred to as “XL”) for the left speaker SpL is included.

  The signal mixing unit 14 performs processing of mixing the acoustic signals XR and XL in which the masking sound M is subjected to stereophonic sound processing in the stereophonic sound processing unit 13 and the input sound I acquired by the input sound signal input unit 12.

  Hereinafter, the signal for the right speaker SpR of the input sound I is referred to as “IR”, and the signal for the left speaker SpL of the input sound I is referred to as “IL”. When the input sound I acquired by the input sound signal input unit 12 is a monaural signal, the input sound signal input unit 12 may convert it into a stereo signal to obtain IR and IL.

  At this time, the signal mixing unit 14 mixes the input sound I with the sound signal X so that the input sound I is sufficiently masked by the component of the masking sound M included in the sound signal X subjected to stereophonic sound processing. It is desirable to adjust the volume. For example, the signal mixing unit 14 may adjust the volume so that the ratio of the volume of the input sound I to the sound signal X is 1: 1. At this time, the volume of the sound signal X may be adjusted in accordance with the volume of the input sound I, or the volume of the input sound I may be adjusted in accordance with the volume of the sound signal X. The signal mixing unit 14 performs processing of mixing the acoustic signal for each speaker (for each channel of the acoustic signal) of the reproduction environment.

  In this embodiment, since the reproduction environment of the acoustic signal processing apparatus 10 is the stereo speakers Sp (speakers SpL and SpR), the signal mixing unit 14 mixes IR and XR to generate an acoustic signal for the right speaker SpR ( Hereinafter, “OR” is generated, and IL and XL are mixed to generate an acoustic signal for the left speaker SpL (hereinafter, referred to as “OL”).

  When a plurality of acoustic signals to be the three-dimensional acoustic masking sound are supplied to the signal mixing unit 14, the signal mixing unit 14 uses the sound obtained by adding all the three-dimensional acoustic masking sounds (acoustic signals) as the acoustic signal X as the input sound. The volume ratio with I may be determined and mixed.

  The speaker output unit 15 distributes and outputs stereo sound sources (acoustic signals OR and OL) processed by the signal mixing unit 14 to the left and right speakers SpL and SpR. Thus, the right speaker SpR reproduces the right speaker sound source (OR), and the left speaker SpL reproduces the left speaker sound source (OL).

  In this embodiment, as described above, the speaker output unit 15 is described as directly supplying the acoustic signal to the speakers SpL and SpR. However, the format for outputting the acoustic signals OR and OL is not limited. For example, the speaker output unit 15 may indirectly transmit (for example, transmit to a device including a speaker) audio data of the acoustic signals OR and OL through communication.

(A-3) Effects of the First Embodiment According to the first embodiment, the following effects can be achieved.

  In the acoustic signal processing apparatus 10 of the first embodiment, the masking sound M is mixed with the three-dimensional acoustic masking sound subjected to three-dimensional acoustic processing and the input sound I (remote sound / far end sound) and supplied to the speakers SpL and SpR. Do. Further, in the acoustic signal processing apparatus 10 according to the first embodiment, the masking sound M is localized for the user U at a different position (different direction) from the position where the sound image of the input sound I (remote sound) is localized. Perform stereophonic sound processing. Furthermore, in the acoustic signal processing apparatus 10 according to the first embodiment, the mixing process of mixing the input sound I as it is with the masking sound M subjected to the three-dimensional acoustic process is performed. Furthermore, in the sound signal processing apparatus 10 according to the first embodiment, when mixing processing is performed, the volume of the input sound I and the masking sound M subjected to stereophonic sound processing are adjusted at a rate at which the masking effect is obtained. Further, in the sound signal processing apparatus 10 according to the first embodiment, the area AS of the sweet spot having the effect of the three-dimensional sound is set to a position where the user U exists. At this time, in the acoustic signal processing apparatus 10 of the first embodiment, the arrangement of the speakers SpL and SpR is arbitrary, and the parameters of the stereophonic sound are set from the positional relationship between the speakers SpL and SpR and the user U.

  As described above, in the first embodiment, the sound reproduced from the speakers SpL and SpR is mixed with the input sound I and the masking sound M (one or more three-dimensional sound masking sounds) subjected to the three-dimensional sound processing. At the position of the user U (the area AS of the sweet spot), as shown in FIG. 2, the user U can be heard from the front (direction X) of the user U, and the stereophonic sound masking sounds MS1, MS2 subjected to stereophonic sound processing are It can be heard from other than the front (directions D1, D2). However, as shown in FIG. 3, for the peripheral person H who is at a place other than the position of the user U (a place other than the area AS of the sweet spot), a state where the input sound I and the stereophonic sound masking sounds MS1 and MS2 are mixed. To make it difficult to hear the input sound I. In other words, unlike the user U who is in the sweet spot area AS, it is difficult for the neighbor H to hear the input sound I in a state where the place where the input sound I can be heard and the place where the masking sound M is heard are not separated. It becomes a state.

  As described above, in the first embodiment, only the user U can hear the input sound I in a clear manner.

  Further, in the first embodiment, the sound signal processing apparatus 10 (the signal mixing unit 14) adjusts and mixes the volume of the input sound I and the masking sound M subjected to stereophonic sound processing, so that it is stable in any environment. Can have the effect of speech privacy.

  Furthermore, in the first embodiment, regardless of the positional relationship between the positions of the speakers SpL and SpR and the user U, localization of the masking sound M can be performed in an arbitrary direction with respect to the user U by the stereophonic sound processing. The installation positions of the speakers SpL and SpR can be set as arbitrary positions.

  Furthermore, as shown in FIG. 2 and FIG. 3, by placing the speakers SpL and SpR near the user U, the sound reproduced from the speakers SpL and SpR also for the voice (near end sound) spoken by the user U It becomes difficult to hear both the input sound I (far end sound) and the voice uttered by the user U (near end sound) for the peripheral person H who is masked at the other than the position of the user U (the area AS of the sweet spot).

  As described above, in the first embodiment, the restriction on the positional relationship between the user U and the speakers SpL and SpR is eased, and the input sound I (far end sound) for only the user U in the sweet spot area AS It is possible to simultaneously achieve the effect of making it difficult for the peripheral person H to listen to the voice (near-end sound) uttered by the user U. That is, in the first embodiment, it is possible to obtain the effect of speech privacy even at the position (lateral direction) next to the user U, which is difficult in the prior art.

(B) Second Embodiment Hereinafter, a second embodiment of the sound processing apparatus, program and method according to the present invention will be described in detail with reference to the drawings.

(B-1) Configuration and Operation of Second Embodiment FIG. 5 is a block diagram showing an overall configuration of an acoustic signal processing device 10A according to a second embodiment. In FIG. 5, the same or symmetrical parts as those in FIG.

  Below, the difference with 1st Embodiment is demonstrated about 10 A of acoustic signal processing apparatuses of 2nd Embodiment.

  In the acoustic signal processing apparatus 10 according to the first embodiment, the masking sound M input at the masking sound signal input unit 11 is subjected to three-dimensional acoustic processing to generate three-dimensional acoustic masking sound. On the other hand, in the acoustic signal processing apparatus 10A of the second embodiment, the sound image is localized at various positions in advance with respect to the masking sound M, instead of receiving the supply of the masking sound M and performing three-dimensional acoustic processing. In addition, the acoustic signal (data of the acoustic signal) of the three-dimensional acoustic masking sound subjected to the three-dimensional acoustic processing is held in a database, and the acoustic signal of the desired three-dimensional acoustic masking sound is selected and used therefrom.

  The acoustic signal processing apparatus 10A shown in FIG. 5 is different from the first embodiment in that the masking sound signal input unit 11 and the three-dimensional sound processing unit 13 are replaced by a masking sound database 16 and a masking sound selection unit 17. ing.

  In the masking sound database 16, acoustic signals (data of acoustic signals) of the three-dimensional acoustic masking sound on which the three-dimensional acoustic processing has been performed are stored in advance so that sound images are localized at various positions with respect to the masking sound M. Here, it is assumed that acoustic signals X (X1 to XN) of N (N is an integer of 2 or more) three-dimensional acoustic masking sounds are accumulated in the masking sound database 16. The sound signals X1 to XN are sound signals in which the masking sound M is localized at different positions. Each acoustic signal X may be an acoustic signal in which the masking sound M is localized at one position, or may be an acoustic signal in which the masking sound M is localized at a plurality of positions.

  Then, the masking sound selection unit 17 selects and acquires one or more acoustic signals X from among the acoustic signals (X1 to XN) of the three-dimensional acoustic masking sound accumulated in the masking sound database 16, and the signal mixing unit 14 Process to supply

  The number and the combination of the acoustic signals X selected by the masking sound selection unit 17 are not limited. The masking sound selection unit 17 may determine the acoustic signal X to be selected, for example, based on the setting according to the operation of the user (for example, a system administrator).

  When a plurality of acoustic signals X are supplied from the masking sound selection unit 17, the signal mixing unit 14 performs processing of mixing the input sound I with the acoustic signal obtained by adding (mixing) all of them.

(B-2) Effects of Second Embodiment According to the second embodiment, the following effects can be achieved.

  In the acoustic signal processing apparatus 10A of the second embodiment, the stereophonic sound processing is omitted, and in order to acquire the acoustic signal X of the stereophonic sound masking sound subjected to stereophonic sound processing from the masking sound database 16, comparison with the first embodiment is made. Real-time throughput can be reduced.

(C) Third Embodiment Hereinafter, a third embodiment of the sound processing apparatus, program and method according to the present invention will be described in detail with reference to the drawings.

(C-1) Configuration and Operation of Third Embodiment FIG. 6 is a block diagram showing the overall configuration of an acoustic signal processing device 10B according to the third embodiment. In FIG. 6, the same or symmetrical parts as in FIG. 1 described above are denoted by the same reference numerals or symmetrical reference numerals.

  Below, the difference with 2nd Embodiment is demonstrated about the acoustic signal processing apparatus 10B of 3rd Embodiment.

  The acoustic signal processing device 10B of the third embodiment is different from the first embodiment in that an output level adjustment unit 18 and a background noise level estimation unit 19 are added. Further, as described above, the third embodiment is different from the first embodiment in that the microphone Mic for collecting the near-end sound including the voice of the user U is installed. The specific configuration of the microphone Mic is not limited. As the microphone Mic, for example, in addition to the omnidirectional microphone, a microphone with directivity, a sound collection device for collecting an area, or the like can be applied.

  In the acoustic signal processing apparatus 10 according to the first embodiment, the output level of the signal mixing unit 14 changes according to the volume of the acoustic signal X of the input sound I or the stereophonic sound masking sound, so other elements (for example, the stereo speaker Sp It is desirable to adjust with the volume control function). On the other hand, in the third embodiment, the noise level of the environment in which the user U is present (near end; sweet spot area AS) is estimated, and the signal mixing unit 14 is calculated according to the estimated noise level. Adjust the output level of In the third embodiment, as shown in FIG. 6, the microphone Mic for picking up the sound (near-end sound) of the area in the sweet spot AS where the user U is located is installed, so the acoustic signal processing apparatus 10B estimates the level of background noise of the environment in which the user U is present from the near-end sound picked up by the microphone Mic.

  Based on the sound collected by the microphone Mic, the background noise level estimation unit 19 sets the level of the background noise at the place where the user U is located (the area AS of the sweet spot) by a predetermined method (the specific method is not limited). presume. The background noise level estimation unit 19 estimates a silent interval in which the voice of the user U (voice in the area AS of the sweet spot) and the voice of the input sound I (voice of the far end talker) are not generated. The background noise may be estimated based on the sound collected by the microphone Mic.

  The background noise level estimation unit 19 may use, for example, a voice section detection technique using information on collected sound to determine whether a voice is generated (determination of a silent section). When the sound picked up by the microphone Mic includes a component of the masking sound M (three-dimensional acoustic masking sound) output from the stereo speakers Sp (speakers SpL and SpR), the background noise level estimation unit 19 uses the microphone Mic. It is desirable to estimate the background noise level after suppressing the component of the masking sound M from the collected sound. When suppressing the component of the masking sound M, the background noise level estimation unit 19 can apply various target sound emphasizing processes such as spectral subtraction.

  The output level adjustment unit 18 adjusts the output level of the signal mixing unit 14 in accordance with the background noise level estimated by the background noise level estimation unit 19. The output level adjustment unit 18 is configured such that, for example, the ratio of the power of the acoustic signal output from the signal mixing unit 14 to the power of the background noise estimated by the background noise level estimation unit 19 is constant. The power level of the audio signal to be output may be adjusted. When the power of the acoustic signal output from the signal mixing unit 14 is S and the power of the estimated background noise is N, the output level adjustment unit 18 sets, for example, an SN ratio (ratio of S to N power) to 10 dB. You may do so.

(C-2) Effects of Third Embodiment According to the third embodiment, the following effects can be achieved.

  In the third embodiment, the output level (volume) of the signal mixing unit 14 is adjusted according to the level (volume) of the background noise at the place where the user U is located (the area AS of the sweet spot). In the third embodiment, for example, the output level of the signal mixing unit 14 is increased as the background noise level increases, and the output level of the signal mixing unit 14 is reduced as the background noise level decreases. Regardless of the environment of a place (a sweet spot area AS), it is possible to keep the user U's easy to hear the input sound I and the user U's speech privacy stable.

(D) Fourth Embodiment Hereinafter, a fourth embodiment of the sound processing device, program and method according to the present invention will be described in detail with reference to the drawings.

(D-1) Configuration of Fourth Embodiment FIG. 7 is a block diagram showing the overall configuration of an acoustic signal processing device 10C according to a fourth embodiment. In FIG. 7, the same parts or symmetrical parts as those in FIG.

  Below, the difference with 3rd Embodiment is demonstrated about 10 C of acoustic signal processing apparatuses of 4th Embodiment.

  In the acoustic signal processing apparatus 10B of the third embodiment, the masking sound M input at the masking sound signal input unit 11 is subjected to stereo acoustic processing to generate a stereo acoustic masking sound. On the other hand, in the acoustic signal processing apparatus 10C of the fourth embodiment, as in the second embodiment, the masking sound database 16 and the masking sound selection unit 17 are provided, and any three-dimensional sound masking sound from the masking sound database 16 Is selected and acquired, and supplied to the signal mixing unit 14. Therefore, as shown in FIG. 7, in the acoustic signal processing device 10C, the third embodiment differs in that the input sound signal input unit 12 and the three-dimensional sound processing unit 13 are replaced by the masking sound database 16 and the masking sound selection unit 17. It differs from the embodiment of

  The masking sound database 16 and the masking sound selection unit 17 have the same configurations as those of the second embodiment, and thus detailed description will be omitted.

  In the acoustic signal processing apparatus 10C of the fourth embodiment, the masking sound selection unit 17 selects and acquires one or more acoustic signals X from the masking sound database 16 as in the second embodiment, and mixes the signals. A process of supplying to the unit 14 is performed.

(D-2) Effects of Fourth Embodiment According to the fourth embodiment, the following effects can be achieved.

  In the acoustic signal processing apparatus 10C of the fourth embodiment, the stereophonic sound processing is omitted, and in order to acquire the acoustic signal X of the stereophonic sound masking sound subjected to stereophonic sound processing from the masking sound database 16, comparison with the third embodiment Real-time throughput can be reduced.

(E) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

  (E-1) In the description of the second and fourth embodiments, an example in which one type of masking sound M is applied has been described, but a plurality of types of masking sound M may be applied. For example, in the second and fourth embodiments, the masking sound database 16 may store a set of acoustic signals X for each masking sound M. For example, when L (L is an integer of 2 or more) masking sounds M (M1 to ML) are present, N acoustic signals X1 to XN are generated for each of the masking sounds M1 to ML to perform masking. It is also possible to store in the sound database 16 (store L / N three-dimensional sound processed masking sounds).

  DESCRIPTION OF SYMBOLS 10 ... Sound signal processing apparatus, 11 ... Masking sound signal input part, 12 ... Input sound signal input part, 13 ... Three-dimensional sound processing part, 14 ... Signal mixing part, 15 ... Speaker output part, AS ... Area | region of sweet spot, D1 ... direction, D2 ... direction, F ... direction, H ... peripheral, I ... input sound, MS1 ... first stereophonic sound masking sound, MS2 ... second stereophonic sound masking sound, SP ... stereo speaker, SpL ... left side speaker , SpR ... right speaker.

Claims (8)

In an acoustic signal processing device that generates an acoustic signal to be supplied to a speaker,
A masking sound for masking an input sound to be listened to by a listener from the speaker is held, and a stereophonic sound masking sound subjected to stereophonic sound processing localized to a place different from a place where the input sound can be heard by the listener is held. Stereophonic sound masking sound holding means;
Mixing means for mixing the three-dimensional sound masking sound and the input sound to generate a mixed sound;
An acoustic signal processing apparatus, comprising: output means for outputting an acoustic signal of mixed sound mixed by the mixing means.   The stereophonic sound masking sound holding means performs stereophonic sound processing to localize the masking sound to a place different from the place where the input sound can be heard by the listener, when the masking sound is supplied, to the stereophonic sound masking The acoustic signal processing apparatus according to claim 1, which holds a sound. The three-dimensional sound masking sound holding means is
A database storing multiple 3D sound masking sounds,
The acoustic signal processing apparatus according to claim 1, further comprising: selection means for selecting and holding one or more three-dimensional sound masking sounds from the database.   The sound signal processing apparatus according to claim 1, wherein the mixing unit adjusts and mixes the volume of the input sound and / or the volume of a three-dimensional sound masking sound. Capturing means for capturing the sound of the place where the listener is located;
A background noise estimating unit that estimates the volume of background noise at the location of the listener based on the sound captured by the capturing means;
The adjusting apparatus according to any one of claims 1 to 4, further comprising: adjusting means for adjusting the volume of the mixed sound generated by the mixing means based on the volume of the background noise estimated by the background noise estimating unit. The acoustic signal processing apparatus as described.   The adjustment means adjusts the volume of the mixed sound so that the ratio of the volume of the mixed sound to the volume of the background noise estimated by the background noise estimation unit is constant. The acoustic signal processing device according to claim 1. A computer mounted on an acoustic signal processing device that generates an acoustic signal to be supplied to a speaker;
A masking sound for masking an input sound to be listened to by a listener from the speaker is held, and a stereophonic sound masking sound subjected to stereophonic sound processing localized to a place different from a place where the input sound can be heard by the listener is held. Stereophonic sound masking sound holding means;
Mixing means for mixing the three-dimensional sound masking sound and the input sound to generate a mixed sound;
A sound reproducing program characterized by functioning as an output means which outputs an acoustic signal of mixed sound mixed by the mixing means. An acoustic signal processing method performed by an acoustic signal processing device that generates an acoustic signal to be supplied to a speaker
3D sound masking sound holding means, mixing means, and output means,
The stereophonic sound masking sound holding means performs stereophonic sound processing to localize the masking sound for masking the input sound to be listened to by the listener from the speaker to a place different from the place where the input sound can be heard by the listener Hold the applied 3D sound masking sound,
The mixing means performs mixing processing for mixing the three-dimensional sound masking sound and the input sound to generate a mixed sound.
The sound reproduction method, wherein the output means outputs an acoustic signal of the mixed sound mixed by the mixing means.

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