JP5644122B2 - Maska sound generator - Google Patents

Description

  The present invention relates to a technique for generating a masker sound and preventing sound leakage.

  Various techniques have been proposed to prevent sound leakage by using the masking effect. The masking effect is that when two kinds of sound signals are propagated in the same space, the person in the space can change the sound characteristics (frequency components, time waveforms, etc.) of the two kinds of sound signals. This is a phenomenon that makes it difficult to notice the sound signal. Many of this type of technology emits masker sounds that hinder the listening of a speaker's voice toward an area where the speaker is located and an area adjacent to the area through a wall or screen. The masker sound in this case may be a noise sound having a spectrum in a wide band, but a sound having characteristics similar to a target sound to be obstructed (hereinafter referred to as a target sound) has a higher masking effect. It is known to be obtained.

  Patent Document 1 discloses a masking system configured to select and emit a sound having the highest masking effect from a plurality of types of masker sounds each time. The masking system disclosed in this document prevents leakage of speech between the acoustic spaces 20A and 20B, which are two adjacent areas across a wall. In this masking system, voices of persons with different ages, languages, genders, etc. are collected in advance. Then, the scrambled sound signal obtained by rearranging the frame arrangement of the collected sound signals of the respective voices is stored in the memory in association with acoustic characteristic information indicating the formant, power spectrum, etc. of those voices. In this masking system, the voice of the speaker in the acoustic space 20A is analyzed to obtain acoustic characteristic information of the voice, and the scrambled sound stored in the memory in association with the acoustic characteristic information closest to the obtained acoustic characteristic information. The signal is read out, and this scrambled sound signal is emitted as a masker sound into the acoustic space 20B. According to this technique, since the masker sound having the characteristics most similar to the voice of the speaker in the acoustic space 20A is emitted to the acoustic space 20B, a high masking effect can be obtained in the acoustic space 20B.

JP 2008-233672-A

In this masking system, in order to maintain the masking effect in the acoustic space 20B, it is necessary to continuously emit the scrambled sound signal selected from a plurality of types as a masker sound in the acoustic space 20B. However, when the same masker sound is repeatedly emitted over a long period of time in this way, the person in the acoustic space 20B feels that the same masker sound is repeatedly emitted and has a problem of being uncomfortable. there were.
The present invention has been devised under such a background, and the periodicity of the masker sound to be emitted is inconspicuous, and the area within the area that emits the masker sound does not give an uncomfortable feeling to the person in the area. The purpose is to obtain a high masking effect.

A masker sound generation device according to a preferred aspect of the present invention includes a buffer that stores a masker sound signal, a sound emission control unit that repeatedly reads out and outputs the masker sound signal stored in the buffer, and obtains a sound signal. And a masker sound signal obtained as a result of executing a rearrangement process for changing the arrangement order of the signals within the processing target every time a predetermined time elapses. And a generation means for changing a method of the rearrangement process each time the rearrangement process is executed.
Further, in another preferred aspect, the masker sound generation device includes an acquisition unit that acquires a sound signal having a predetermined time length, and the sound signal acquired by the acquisition unit as a processing target, and the arrangement order of the signals within the processing target The random number sequence is repeatedly changed according to the random number sequence, the process of outputting the masker sound signal obtained as a result is repeated, and each time a certain time longer than the predetermined time length elapses, the random number sequence And generating means for repeatedly changing the rearrangement processing method according to a random number sequence changed to a different type.

According to the present invention, the audibility of the masker sound signal changes every time the generating means changes the rearrangement processing method. Therefore, compared with the case where the same masker sound signal is continuously emitted, it is possible to reduce the uncomfortable feeling given to the person in the area of the sound emission destination.

  Further, the generation unit divides the sound signal acquired by the acquisition unit into a plurality of sections having a predetermined time length, and repeats a rearrangement process of rearranging the divided sections as a process of changing the arrangement order. The method of rearranging each section may be changed each time.

  According to this masker sound generation device, the arrangement order is changed for each sound signal for a certain length of time. Therefore, it is possible to generate a masker sound signal with a higher masking effect than in the case where the arrangement order of the sound signals is changed sample by sample.

  In addition, the acquisition unit acquires a plurality of types of sound signals to generate one type of masker sound signal, and the generation unit constantly determines the type of sound signal for each type of the plurality of types of sound signals. Dividing into a plurality of time length sections and rearranging the rearrangement of the sections as a process of changing the arrangement order may change the section rearrangement method for each of the plurality of types of sound signals. Good.

  According to this masker sound generation device, since a plurality of types of sound signals are mixed to form a masker sound signal, a high masking effect can be generated even when there are a plurality of masking target sounds.

  Further, the generation means performs an intra-interval reversal process for reversing the arrangement of the sound signals in each segment obtained by dividing the sound signal, and uses the signals that have undergone both the intra-interval reversal process and the segment rearrangement process, as described above. A masker sound signal may be generated.

  In addition, the generation unit adds an acoustic effect to the rearranged signals of the sections with respect to at least some types of the plurality of types of sound signals, and the signal to which the acoustic effect is added is mixed. It is good also as an object of.

  According to another aspect of the present invention, there is provided a masker sound generating apparatus that includes an acquisition unit that acquires a sound signal, an arrangement order of the sound signals acquired by the acquisition unit, and an acoustic signal that changes the arrangement order. It is characterized by comprising generating means for repeating the process of giving an effect and outputting a signal to which the acoustic effect is given as a masker sound signal, and repeatedly changing the method of giving the acoustic effect.

  According to this masker sound generating device, the audibility of the masker sound signal changes every time the generating means changes the method of applying the acoustic effect. Therefore, compared with the case where the same masker sound signal is continuously emitted, it is possible to reduce the uncomfortable feeling given to the person in the area of the sound emission destination.

  Further, the masker sound generation device according to another preferred aspect of the present invention includes an acquisition unit that acquires a plurality of types of sound signals, and an arrangement order of the plurality of types of sound signals acquired by the acquisition unit, For at least some types of sound signals among the plurality of types of sound signals that have been changed, an acoustic effect is imparted to the signal after the change of the order of arrangement, and the signal to which the acoustic effect is imparted is mixed and output as a masker sound signal And generating means for repeating the process and repeatedly changing the mixing method.

  According to this masker sound generating device, the audibility of the masker sound signal changes every time the generating means changes the mixing method. Therefore, compared with the case where the same masker sound signal is continuously emitted, it is possible to reduce the uncomfortable feeling given to the person in the area of the sound emission destination.

  According to another aspect of the present invention, there is provided a masker sound generating device that changes an arrangement order of a plurality of types of sound signals acquired by the acquisition unit, and at least one of the plurality of types of sound signals whose arrangement order is changed. For the sound signal of the part type, a sound effect is given to the signal after the change of the order of arrangement, and the signal obtained by mixing the signal to which the sound effect is added is set as the processing target of the repeated processing, and the order of the signal as the processing target is changed. And generating means for repeating the process of outputting the generated sound signal as a masker sound signal and repeatedly changing the method of changing the arrangement order.

  Also with this masker sound generating device, the audibility of the masker sound signal changes every time the generating means changes the method of changing the arrangement order. Therefore, compared with the case where the same masker sound signal is continuously emitted, it is possible to reduce the uncomfortable feeling given to the person in the area of the sound emission destination.

  According to another preferred aspect of the present invention, there is provided a program for acquiring, as a masker sound signal, an acquisition unit that acquires a sound signal and a signal obtained by changing an arrangement order of the sound signals acquired by the acquisition unit. And generating means for repeatedly changing the method of changing the arrangement order.

It is a block diagram which shows the structure of the masker sound production | generation apparatus which is 1st-5th embodiment of this invention. It is a figure which shows an example of the aspect of installation of the same masker sound production | generation apparatus. It is a data structure figure of the sound database which the same masker sound production | generation apparatus memorize | stores. It is a flowchart which shows operation | movement of the masker sound production | generation apparatus which is 1st Embodiment of this invention. It is a figure which shows the mode of the process of the sound signal by the same masker sound production | generation apparatus. It is a flowchart which shows operation | movement of the masker sound production | generation apparatus which is 2nd Embodiment of this invention. It is a figure which shows the mode of the process of the sound signal by the same masker sound production | generation apparatus. It is a flowchart which shows operation | movement of the masker sound production | generation apparatus which is 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the masker sound generation apparatus which is 4th Embodiment of this invention. It is a flowchart which shows operation | movement of the masker sound generation apparatus which is 5th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a configuration of a masker sound generation apparatus 10 according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of how the masker sound generation device 10 is installed. As shown in the example of FIG. 2, the masker sound generation device 10 is installed in a region A separated from the outside by a partition 50. This area A is provided with a human sensor 30 that detects the entry of a speaker into the area A and the exit of the speaker outside the area A. The masker sound generation device 10 moves the partition 50 from the region A until the human sensor 30 detects that the speaker has entered the region A until it detects that the speaker has left the region A. The speech that is transmitted to the region B outside the target sound T is set as the target sound T, and a masker sound signal M that prevents the target sound T from being heard is emitted from the speaker 31 in the region B.

  In FIG. 1, the masker sound generation device 10 includes a hard disk 11, a control unit 12, a buffer 13, a sound emission control unit 14, a D / A conversion unit 15, and an amplifier 16. The hard disk 11 stores a sound database 21. The sound database 21 is an aggregate of a plurality of records corresponding to voices of time length T1 (for example, T1 = 30 seconds) recorded from persons with various voice characteristics. As shown in FIG. 3, a record corresponding to one voice in the database 21 includes a “voice” field indicating a sound signal S corresponding to the time length T1 of the voice, and an “attribute” indicating attribute information of the voice. Field. The attribute information is, for example, information indicating a combination of the gender of the voice recording source person and the pitch of the voice (high, medium, and low sounds). There are six types of attribute information: “male, treble”, “male, middle tone”, “male, bass”, “female, treble”, “female, middle tone”, “female, bass”.

  The control unit 12 includes a CPU 22, a RAM 23, and a ROM 24. The CPU 22 executes the masker sound generation program 25 stored in the ROM 24 while using the RAM 23 as a work area. The masker sound generation program 25 is a program that causes the CPU 22 to execute two processes of an acquisition process and a generation process. The acquisition process is a process of acquiring a plurality of types of sound signals S from the sound database 21 and storing them in the RAM 23. In the generation process, a signal obtained by changing the arrangement order of the sound signals S stored in the RAM 23 is set as a masker sound signal M, and the output of the masker sound signal M to the buffer 13 is repeated, and the change of the arrangement order changing method is repeated. It is processing. Details of the acquisition process and the generation process will be described later. The sound emission control unit 14 is a circuit that repeats the process of reading the latest masker sound signal M written in the buffer 13 and outputting it to the D / A conversion unit 15. The D / A conversion unit 15 converts the masker sound signal M output via the sound emission control unit 14 into an analog signal and outputs the analog signal to the amplifier 16. The amplifier 16 amplifies the analog signal output from the D / A converter 15 and outputs it as sound from the speaker 31.

Next, the operation of this embodiment will be described. CPU22 of the masking sound generating apparatus 10, given the detection signal S _IN indicating that a speaker has entered the region A from the motion sensor 30, executes a generation process and acquisition process. In the acquisition process, the CPU 22 has the sound signal S associated with the attribute information “male, treble”, the sound signal S associated with the attribute information “male, medium sound”, and the attribute information “male, bass”. , The sound signal S associated with the attribute information of “female, treble”, the sound signal S associated with the attribute information of “female, medium sound”, and “female, bass” The sound signals S associated with the attribute information are selected one by one from the sound database 21, and these six types of sound signals S are acquired from the database 21 and stored in the RAM 23. Hereinafter, for convenience of explanation, each of the six types of sound signals S stored in the RAM 23 by this acquisition process will be referred to as sound signals Sa, Sb, Sc, Sd, Se, Sf.

  In the generation process, the CPU 22 performs the processing from step S100 to step S120 shown in FIG. 4 for the six types of sound signals Sa, Sb, Sc, Sd, Se, and Sf as processing targets, and thereafter, step S130 shown in FIG. The loop process of step S190 is repeated every time length T2 (for example, T2 = 1 minute). Hereinafter, details of the processing in steps S100 to S190 will be described.

First, as shown in FIG. 5A, the CPU 22 sets each of the six types of sound signals Sa, Sb, Sc, Sd, Se, and Sf to a time length T3 (for example, T3 = 100 milliseconds). Is divided into N (N = T1 / T3) frames F _i (i = 1 to N) (S100). In FIG. 5A, the case of N = 15 is shown in order to prevent the drawing from becoming complicated.

As shown in FIG. 5B, the CPU 22 performs in-frame reverse processing (S110). Frame reversal process, sound signals Sa, Sb, Sc, Sd, Se, and Sf respectively frame _F sound signals reversed the sequence of sample data in the _{i Sa} R in _{the, Sb R, Sc R, Sd} R, This is a process for generating Se _R and Sf _R.

When the CPU 22 finishes the intra-frame reverse process, as shown in FIG. 5C, the sound signals Sa _R , Sb _R , Sc _R , Sd _R , Se _R , and Sf _R that are the processing results of the intra-frame reverse process. Is multiplied by the window function ω (S120). This window function omega, is intended for waveform shaping to facilitate coupling between the divided frames F _i.

Next, as shown in FIG. 5D, the CPU 22 performs frame rearrangement processing on the sound signals Sa _W , Sb _W , Sc _W , Sd _W , Se _W , and Sf _W multiplied by the window function ω. (S130). In the frame rearrangement process, the CPU 22 randomly rearranges the arrangement of the frames F _i (i = 1 to 15) of the sound signals Sa _W , Sb _W , Sc _W , Sd _W , Se _W , and Sf _W. Sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S are generated.

Hereinafter, a specific procedure will be described with reference to an example of a frame rearrangement process using the sound signal Sa _W as a processing target. When the number of frames N obtained by dividing the sound signal Sa _W is 15, the CPU 22 generates a random number sequence consisting of numbers from 1 to 15. Then, 15 random numbers are read in order from the top, and if the first random number is 8, the first frame before the rearrangement is the eighth frame after the rearrangement, and the second random number is 4. For example, the second frame before rearrangement is set as the fourth frame after rearrangement, and so on, and the order after rearrangement of the frames is determined according to the random number sequence. A sound signal Sa _S is obtained by rearranging the first to fifteenth frames. Here, in the present embodiment, in order to change the rearrangement method, a plurality of types of random number sequences with different random number sequences (if N = 15, all are random number sequences consisting of 15 random numbers) are prepared. To do. Each time the frame rearrangement process is performed, the type of random number sequence used for rearrangement is changed.
The CPU 22 similarly performs the frame rearrangement processing for processing the sound signals Sb _W , Sc _W , Sd _W , Se _W , and Sf _W.

When the frame rearrangement process is completed, the CPU 22 performs an acoustic effect applying process on the sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S (S140). In the sound effect applying process, the CPU 22 applies a predetermined sound effect (for example, reverb) to the sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S generated as a result of the frame rearrangement process. ) To which the sound signals Sa _S ′, Sb _S ′, Sc _S ′, Sd _S ′, Se _S ′, and Sf _S ′ are added. When the sound effect applying process is finished, the CPU 22 performs a mixing process (S150). In the mixing process, the CPU 22 converts the sound signals Sa _S ', Sb _S ', Sc _S ', Sd _S ', Se _S ', and Sf _S ' subjected to the sound effect applying process into a predetermined mixing ratio (for example, 1: 1: 1: 1: 1: 1), and the mixed signal is a masker sound signal M. When the mixing process is completed, the CPU 22 performs a speech speed conversion process (S160). In the speech speed conversion process, the CPU 22 expands the time axis of the masker sound signal M corresponding to the time length T1 generated by the mixing process to obtain the masker sound signal M corresponding to the time length T1 ′ (T1 ′> T1). More specifically, in this speech speed conversion process, the CPU 22 excludes the rising portion and falling portion of the sound waveform from the frame F _i (i = 1 to 15) in the masker sound signal M to be processed. The frame F _i of the stationary part is duplicated as many times as necessary to make up the time difference between the time length T1 and the time length T1 ′, and the duplicated frame F _i ′ is inserted between the frames F _i and F _{i + 1} of the stationary part. .

The CPU 22 outputs the masker sound signal M subjected to the speech speed conversion process and overwrites the buffer 13 (S170). The CPU 22 does not receive the detection signal _SOUT indicating that the speaker has left the area A from the human sensor 30 (S180: No), and the time length T2 (T2 = 1 minute) from the execution of step S130. (S190: Yes), the process returns to step S130 and the subsequent processing is repeated. On the other hand, when the detection signal S _OUT is given from the human sensor 30 (S180: Yes), the sound emission control unit 14 is instructed to stop reading the masker sound signal M, and the process is ended.

According to the embodiment described above, the following effects can be obtained.
First, in this embodiment, a masker sound signal M is generated from six types of sound signals Sa, Sb, Sc, Sd, Se, and Sf. Therefore, even when there are a plurality of speakers having different voice characteristics in the region A, a high masking effect can be generated in the region B.

Secondly, in the present embodiment, the frame rearrangement process is performed every time length T2 by repeating the frame rearrangement process for the sound signals Sa _W , Sb _W , Sc _W , Sd _W , Se _W , and Sf _W for each time length T2. The sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _{S in} which the arrangement of the frames F _i (i = 1 to 15) is randomly changed by the above are emitted as a masker sound signal M in the region B. To do. In the present embodiment, the frame rearrangement method is changed every time the process proceeds to the frame rearrangement process (step S130). As a result, the audibility of the masker sound signal M emitted in the region B changes every time length T2. Therefore, compared with the case where the masker sound signal M having the same arrangement of the frames F _i (i = 1 to 15) is continuously emitted into the region B for a long time, it is less likely to give a strange feeling to those in the region B. can do.

Third, in the present embodiment, the sound signals Sa _S ′, Sb _S ′, Sc _S ′, Sd _S ′, Se _S ′, and Sf _S ′ are mixed to obtain a masker sound signal M, and then the masker sound After extending the time axis of the signal M, sound is output to the region B. When processing (step S110 and step S130) for changing the arrangement of sound signals indicating human speech is performed, the processed sound signal is usually similar to the speech of a person who speaks quickly. It has a characteristic of sound. However, according to the present embodiment, it is possible to relieve the impression that such a fast speech is heard. Further, according to the present embodiment, it is not necessary to carefully select and store in the sound database 21 a sound signal that is unlikely to be a quick impression when the arrangement is changed.

Fourth, in the present embodiment, the sound effect is applied after mixing the six types of sound signals Sa _S ′, Sb _S ′, Sc _S ′, Sd _S ′, Se _S ′, and Sf _S ′. The masker sound signal M to which the acoustic effect is added in this manner is acoustically similar to the voice (target sound T) to which the spatial acoustic effect (reverberation) is given by propagation in the region B. . Therefore, a high masking effect can be obtained in the region without giving a sense of incongruity to the person in the region where the masker sound is emitted.

Second Embodiment
Next, a second embodiment of the present invention will be described. As illustrated in FIG. 6, in the generation process in the present embodiment, the CPU 22 rearranges the frames F _i (i = 1 to 15) by the frame rearrangement process after performing the frame rearrangement process in step S <b> 130. The sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S are targeted for processing, and the loop processing from step S140 to step S190 is repeated for each time length T2. In this case, the CPU 22 randomly changes the reverb depth (level ratio between the direct sound and the reverberant sound), which is an acoustic effect, every time the acoustic effect applying process in step S140 in each loop process. More specifically, as shown in FIG. 7, the CPU 22 performs a process of generating a reverberation sound signal RSa _S from the sound signal Sa _{S in the} sound effect applying process. In this processing, a delayed sound signal DSa _S −n (n = 1, 2,...) Obtained by delaying the sound signal Sa _S is obtained, and the delayed sound signal DSa _S −n (n = 1, 2,...) Is added. The reverberation signal RSa _{S is} assumed. Next, a random number is generated, and a product obtained by adding the product of the random number and the reverberation sound signal RSa _S to the sound signal Sa _S is defined as a sound signal Sa _S ′ with an acoustic effect. Hereinafter, similarly, the CPU 22 calculates the product of each individually generated random number and the reverberation sound signals RSb _S , RSc _S , RSd _S , RSe _S , and RSf _S as sound signals Sb _S , Sc _S , Sd _S , Se _S. , And Sf _S are added to sound signals Sb _S ′, Sc _S ′, Sd _S ′, Se _S ′, and Sf _S ′.

  In the present embodiment, since the contents of the sound effect applying process (S140) are changed for each time length T2, the audibility of the masker sound signal M emitted in the region B changes for each time length T2. Therefore, it is possible to make it difficult for a person in the region B to feel uncomfortable.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. As shown in FIG. 8, in the generation process in the present embodiment, the CPU 22 performs the sound effect applying process in step S140, and then performs sound signals Sa _S 'and Sb _S ' to which the sound effect is applied by the sound effect applying process. , Sc _S ′, Sd _S ′, Se _S ′, and Sf _S ′ are processed, and the loop processing from step S150 to step S190 is repeated every time length T2. In this case, the CPU 22 randomly sets the mixing ratios of Sa _S ', Sb _S ', Sc _S ', Sd _S ', Se _S ', and Sf _S ' at each mixing process of step S150 in each loop process. Change. More specifically, in the mixing process, the CPU 22 generates six types of random numbers (excluding 0), and each of these random numbers is used as a sound signal Sa _S ', Sb _S ', Sc _S ', Sd _S '. , Se _S ′, and Sf _S ′.

  In the present embodiment, since the content of the mixing process (step S150) is changed for each time length T2, the audibility of the masker sound signal M emitted in the region B changes for each time length T2. Therefore, it is possible to make it difficult for a person in the region B to feel uncomfortable.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. As shown in FIG. 9, in the generation process in the present embodiment, the CPU 22 performs the mixing process in step S150, and then repeats the loop process in steps S160 to S200 every time length T2. The contents from step S160 to step S190 in this loop processing are the same as the contents from step S160 to step S190 of the first embodiment. That is, the CPU 22 does not receive the detection signal _SOUT indicating that the speaker has left the area A from the human sensor 30 (S180: No), and when the time length T2 has elapsed (S190: Yes), the step Proceed to S200.

In step S200, the CPU 22 performs a frame rearrangement process on the masker sound signal M that is the processing result of the mixing process in step S150. In the frame rearrangement process in step S200, the CPU 22 again divides the masker sound signal M into frames F _i (i = 1 to 15), and randomly rearranges the divided frames F _i (i = 1 to 15). A masker sound signal M is generated. After executing the frame rearrangement processing in step S200, the CPU 22 returns to step S160, performs speech speed conversion processing on the newly generated masker sound signal M, proceeds to step S170, and stores the masker sound signal M in the buffer 13. Overwrite.

  In the present embodiment, since the frame rearrangement method is changed every time length T2, the audibility of the masker sound signal M emitted in the region B changes every time length T2. Therefore, it is possible to make it difficult for a person in the region B to feel uncomfortable.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described. As shown in FIG. 10, in the generation process in the present embodiment, the CPU 22 performs the speech speed conversion process in step S160, and then repeats the loop process in steps S170 to S200 for each time length T2. In the frame rearrangement process of step S200 in this loop process, the CPU 22 performs the frame rearrangement process on the masker sound signal M whose time axis is expanded by the speech speed conversion process of step S160. The contents of the frame rearrangement process in step S200 are the same as the contents of the same process in the fourth embodiment.

  Also in this embodiment, since the frame rearrangement method is changed every time length T2, the audibility of the masker sound signal M emitted in the region B changes every time length T2. Therefore, it is possible to make it difficult for a person in the region B to feel uncomfortable.

The first to fifth embodiments of the present invention have been described above. However, the present invention may have other embodiments. For example, it is as follows.
(1) In the masker sound generation device 10 of the first to fifth embodiments, a plurality of selection items are presented for each of a plurality of types of attributes such as gender and voice pitch, and at least one type of selection item of attributes is presented. The CPU 22 reads from the sound database 21 one or a plurality of types of sound signals S whose recording source is a person having the attribute of the selection item selected by the selection support means. The masker sound signal M may be generated using the read sound signal S as a material.

  This embodiment is realized as follows, for example. First, in the sound database 21, high-frequency male, medium-frequency male, and low-frequency male voices are mixed with “male” attribute information, high-frequency female, medium-frequency female, and low-frequency female voices. MIX information and "female" attribute information, high-frequency male and female voice mixing information and "high-pitched" attribute information, middle-tone male and female voice mixing information and "middle sound" attribute information, bass A mix of male and female voices and attribute information of “bass” are stored in association with each other.

  Then, when one of the sex selection items (male, female) is selected by the operation support means, the CPU 22 generates a sound signal S that makes a pair with the attribute information selected from “male” and “female”. A masker sound signal M is generated by reading from the database 21 and using the sound signal S as a material. In addition, when one of the voice pitch selection items (high tone, middle tone, low tone) is selected by the operation support means, the CPU 22 selects one of “high tone”, “medium tone”, and “low tone”. The sound signal S paired with the attribute information is read from the sound database 21, and a masker sound signal M is generated using the sound signal S as a material.

  According to this embodiment, even when a user designates only some types of selection items among a plurality of types of attributes of the user, a masker sound that generates a high masking effect on the user's voice A signal M can be generated. In addition, a plurality of types of sound signals S associated with other types of attribute information (for example, language and age) are stored in the sound database 21, and the material selected for the masker sound signal M is selected according to the designation of the operating means. It is good.

(2) In the sound effect imparting process of the first to fifth embodiments, the sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and other kinds of sound effects other than reverb such as delay, harmony, and distortion are used. And Sf _S.

(3) In the first to fifth embodiments, the order of processing in step S110 and step S120 Conversely, the sound signal Sa, Sb, Sc, Sd, Se, and window function to the frame _{F i} at each of the Sf omega And the arrangement of the sample data in each frame F _i may be reversed.

(4) In the second embodiment, the sound effect is applied among the six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S each time the sound effect applying process is repeated. You may change the combination of a thing and the thing which does not provide an acoustic effect. Further, each time the sound effect applying process is repeated, the types of sound effects applied to each of the six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S may be changed. Also, each time repeating the sound effect imparting processing, six kinds of sound signals _{Sa S, Sb S, Sc S} , Sd S, Se S, and each frame _F i (i = _1~15) of Sf _S of combinations may be changed in the frame F _i that does not impart frame F _i and sound effect imparting sound effects.

(5) In the first embodiment, the frame rearrangement process for each of the sound signals Sa _W , Sb _W , Sc _W , Sd _W , Se _W , and Sf _W is repeated for each time length T2. However, the frame rearrangement process is performed for each of different time lengths T2 _a , T2 _b , T2 _c , T2 _d , T2 _e , and T2 _f that are unique to the plurality of types of sound signals Sa, Sb, Sc, Sd, Se, and Sf. It may be repeated. In this case, if the time lengths T2 _a , T2 _b , T2 _c , T2 _d , T2 _e , and T2 _f are lengths that are relatively prime to each other (length that is a prime number ratio such as 1: 3: 5). Good. In this way, the period of change in the audibility of the masker sound M emitted in the region B becomes substantially longer, and it is possible to make it more difficult to give an uncomfortable feeling to those in the region B. Similarly, it is time to repeat the acoustic effect imparting process in step S140 in the second embodiment, the mixing process in step S150 in the third embodiment, and the frame rearrangement process in step S200 in the fourth and fifth embodiments. long _{T2 a, T2 b, T2 c} , T2 d, T2 e, may be performed for each T2 _f.

(6) In the first to fifth embodiments, the time length T2 for repeating the loop processing is set longer than the time length T1 of the voice that is the material of the masker sound signal M (T2 = 1 minute, T1 = 30 seconds). However, the time length T2 may be the same as the time length T1. Alternatively, the time length T2 may be the same as the time length T1 '(the length of the masker sound signal M that has undergone the speech speed conversion process). Further, the time length T2 at which the loop process is repeated may be determined randomly using a random number.

(7) In the first to fifth embodiments, the sound effect applying process (S140) is performed on all six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S as processing targets. went. However, the acoustic effect imparting process may be performed on a part of the six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S as a processing target.

(8) In the first to fifth embodiments, intra-frame inversion processing (S110) with all six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S as processing targets. , A process of multiplying the window function (S120), a frame rearrangement process (S130), and a sound effect applying process (S140), and the sound signals Sa _S ', Sb _S ', Sc _S 'as the processing results are performed. , Sd _S ′, Se _S ′, and Sf _S ′ are mixed to obtain a masker sound signal M. However, some of the six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S (for example, sound signals Sa _S , Sb _S , Sc _S , Sd _S and On the other hand, the processes of steps S110 to S140 are performed, while the remaining sound signals Se _S and Sf _S are not subjected to any of the processes of steps S110 to S140, and the processes of steps S110 to S140 are performed. A masker sound signal M may be obtained by mixing the sound signals Sa _S ′, Sb _S ′, Sc _S ′, and Sd _S ′ and the sound signals Se _S and Sf _S , which are the processing results of the processing. In this case, for some or all of the sound signals Sa _S , Sb _S , Sc _S , Sd _S , in-frame inversion processing (S 110), processing for multiplying a window function (S 120), or The processing result obtained up to the frame rearrangement processing (S130) may be the target of mixing.

(9) In the first to fifth embodiments, the frame rearrangement process (S130) is performed after the intra-frame reverse process (S110). However, in-frame inversion processing may be performed after the frame rearrangement processing.

(10) In the first to fifth embodiments, the six types of sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S are first mixed, and the mixed sound signal is processed as a processing target. Each process of S110 to S140 may be performed, and the processing result of each process of S110 to S140 may be a masker sound signal M.

(11) In the first to fifth embodiments, the sound signal Sa _S , Sb _S , Sc _S , Sd _S , Se from the sound database 21 every time the human sensor 30 detects the speaker entering the area A. _{S 1} and Sf _S are read out, and the masker sound signal M obtained by performing each of the steps S100 to S190 with the sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S being processed is obtained. Radiated to region B. However, the masker sound signal M obtained by performing each process of step S100 to step S190 is stored in the memory, and thereafter, every time the human sensor 30 detects the speaker's entry, the masker sound signal M in the memory is stored. You may make it read and repeatedly radiate | emit to the area | region B. In this case, the sound signals Sa _S , Sb _S , Sc _S , Sd _S , Se _S , and Sf _S having a length of time length T1 (T1 = 30 seconds) are used as materials, as shown in FIGS. By repeating the series of processes of FIG. 9 or FIG. 10 a plurality of times, a masker sound signal M for a time length T4 (for example, T4 = 10 minutes) sufficiently longer than the time length T1 is generated, and this time length T4 The minute masker sound signal M may be stored in a memory and used.

(12) In the first to fifth embodiments, the present invention is applied to the prevention of sound leakage from the area A partitioned by the partitions 50 to the external area B. However, it is difficult to hear the sound generated in one area A ′ (or B ′) of the two areas A ′ and B ′ where the partition 50 or the like is not interposed, in the other area B ′ (or A ′). The present invention may be applied to. Also, a masker sound generator 10 is installed in a room separated from the outside by four walls and a ceiling, and the masker sound signal M generated by the masker sound generator 10 is emitted toward an area outside the wall. You may make it do. In addition, the present invention may be applied to a purpose of making it difficult to hear each speaker's voice in a communication device (for example, a mobile phone, an IP phone, an interphone, etc.) that realizes a call between people in different spaces. . In this embodiment, for example, the masker sound generation device 10 according to the first to fifth embodiments is built in the communication device, and the masker sound signal M generated by the masker sound generation device 10 is emitted around the speaker. It is feasible. In this case, it is more preferable to prevent the situation where the masker sound signal M is transmitted to the other party of the call and the conversation is confused by attaching the earphone to the speaker or controlling the directivity of the speaker of the communication device.

(13) In the first to fifth embodiments, a microphone may be installed in the area A. In this case, the CPU 22 may acquire a sound signal picked up by the microphone in the region A in the acquisition process, and generate a masker sound signal M from the acquired sound signal in the generation process.

(14) In the first to fifth embodiments, the human sensor 30 may be an acoustic sensor (for example, a microphone that detects sound waves, a vibration pickup that detects vibration), or a biosensor (for example, A thermal sensor for detecting the heat of the living body, an infrared sensor for detecting the infrared ray of the living body, and the like. In addition, a sound collection / detection device having both the function of the microphone and the function of the human sensor 30 shown in (15) is installed in the region A, and the speaker enters the region A by the sound collection / detection device. When the signal is detected, the masker sound signal M may be generated using a sound signal collected by the apparatus thereafter as a material.

(16) In the first to fifth embodiments, the hard disk 11 may be an external element of the masker sound generation device 10. In this embodiment, sound signals Sa, Sb, Sc, Sd, Se, and Sf are acquired from a sound database 21 in an external storage device via a network, and the sound signals Sa, Sb, Sc, Sd, Se are acquired. , And Sf may be used as a material to generate a masker sound signal M. All or some of the buffer 13, the sound emission control unit 14, the D / A conversion unit 15, and the amplifier 16 may be external elements of the masker sound generation device 10. In this embodiment, for example, the masker sound signal M generated using the sound signals Sa, Sb, Sc, Sd, Se, and Sf as a material may be output to an external storage device serving as the buffer 13 via various interfaces. .

(18) In the above first to fifth embodiment, CPU 22 of the masking sound generating apparatus 10, given the detection signal S _IN indicating that a speaker has entered the region A, and a generation process and acquisition process Executed. However, when the detection signal _SIN is given, the masking sound signal M stored in advance in the hard disk 11 or other memory may be output from the speaker 31 without executing the acquisition process and the generation process.

(19) In the frame rearrangement process of the first to fifth embodiments, a random number sequence composed of numbers 1 to N different from each other is used for frame rearrangement. However, a random number sequence in which the same random number appears multiple times in the random number sequence may be used for frame rearrangement. If the first random number is 8, the 8th frame before the rearrangement is the first frame after the rearrangement, and if the second random number is 4, the 4th frame before the rearrangement is after the rearrangement. In this way, the frame to be selected from those before rearrangement may be determined according to the random number sequence.

(20) In the second embodiment, the CPU 22 changes the reverb depth (ratio between direct sound and reverberant sound) every time the acoustic effect is applied. However, the length (decay time) of the reverberant sound may be changed every time the acoustic effect applying process is performed. In this embodiment, the CPU 22 changes the strength of the delayed sound signal DSa _S −n (n = 1, 2,...) Obtained by delaying the sound signal Sa _S every time the acoustic effect applying process is performed. The length of the sound (decay time) may be changed, or the delay of the delayed sound signal DSa _S −n (n = 1, 2,...) Obtained by delaying the sound signal Sa _S each time the sound effect is applied. The length (decay time) of the reverberant sound may be changed by changing the time.

DESCRIPTION OF SYMBOLS 10 ... Masker sound production | generation apparatus, 11 ... Hard disk, 12 ... Control part, 13 ... Buffer, 14 ... Sound emission control part, 15 ... D / A conversion part, 16 ... Amplifier, 21 ... Sound database, 22 ... CPU, 23 ... RAM, 24 ROM, 30 human sensor, 31 speaker.

Claims (6)

A buffer for storing masker sound signals;
A sound emission control unit that repeatedly reads out and outputs a masker sound signal stored in the buffer;
An acquisition means for acquiring a sound signal;
The sound signal acquired by the acquisition unit is set as a processing target, and a reordering process for changing the order of arrangement of the signals in the processing target is executed every time a predetermined time elapses, and the masker sound signal obtained as a result thereof is stored in the buffer. A masker sound generating apparatus , comprising: a means for overwriting, and a generating means for changing a method of the rearrangement process each time the rearrangement process is executed . Obtaining means for obtaining a sound signal of a predetermined time length;
A process for processing the sound signal acquired by the acquisition unit as a processing target, executing a rearrangement process for randomly changing the arrangement order of the signals in the processing target according to a random number sequence, and outputting a masker sound signal obtained as a result And generating means for repeatedly changing the rearrangement processing method according to the random number sequence changed to a different type from the random number sequence every time a predetermined time longer than the predetermined time length elapses.
A masker sound generating apparatus comprising: The generating means sets each signal obtained from a plurality of types of sound signals as a processing target, and changes a rearrangement processing method applied to each of the plurality of types of processing targets each time the predetermined time elapses. 3. The masker according to claim 1, wherein a reordering process is performed on each of the plurality of types of processing targets, and a masker sound signal is generated by mixing each processing target after the reordering process. Sound generator. The process according to claim 1, wherein the process of obtaining the processing target from the sound signal by the generating unit includes at least a division process of dividing the sound signal into a plurality of sections. Masker sound generator. The process in which the generating means obtains the processing target from the sound signal includes an intra-section reversal process for reversing the arrangement of the sound signals in each section of the plurality of sections obtained through the division process. The masker sound generation device according to claim 4. 5. The process of obtaining the processing target from the sound signal by the generating means includes a window function multiplication process of multiplying a plurality of sections obtained by the division process by a window function. Or a masker sound generating device according to 5;

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