JP2006139158A - Sound signal synthesizer and synthesizing/reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound signal synthesizer capable of creating a novel sound signal while allowing the influence of sound signals prior to synthesizing to remain in synthesizing a plurality of the sound signals, and a sound signal synthesizing/reproducing apparatus capable of reproducing the sound signals simultaneously with synthesizing the same. <P>SOLUTION: A block read means 10 reads the plurality of the sound signals in sound block unit consisting of a prescribed number of samples from a sound signal memory section 61 and a frequency conversion means 20 applies Fourier transform to the sound blocks read from the respective sound signals to obtain spectral blocks. A block read means 30 generates synthesized spectral blocks by synthesizing the spectral blocks obtained from the respective sound signals and generates the synthesized sound blocks by Fourier inverse transformation. The generated synthesized sound blocks are sequentially outputted by an output means 50 and the synthesized sound signals are recorded in a synthesized sound signal memory section 60. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a method for synthesizing an acoustic signal suitable for use in the field of package music reproduction for appreciation in consumer / business use using CD / DVD, and in the BGM field distributed for commercial purposes by broadcasters / public facility operators. Regeneration technology.

Conventionally, in general music production, a plurality of acoustic signals are often superimposed on a waveform. (For example, refer to Patent Documents 1 and 2).
Japanese Patent No. 2671825 Patent No. 3092592

  However, with the conventional method, the acoustic signal obtained after synthesis is simply the sum of the original acoustic signals. In other words, when sound signals played by different musical instruments are synthesized, an acoustic signal in a state of being played by two musical instruments is obtained, and it is impossible to create new music.

  Therefore, the present invention provides an apparatus for synthesizing an acoustic signal capable of creating a new acoustic signal while retaining the influence of the acoustic signal before synthesis when synthesizing a plurality of acoustic signals, and reproducing simultaneously with the synthesis. It is an object of the present invention to provide an apparatus for synthesizing and reproducing an acoustic signal that can be used.

  In order to solve the above problems, in the present invention, as a device for synthesizing a plurality of acoustic signals composed of time-series sample sequences and generating a synthesized acoustic signal, a predetermined number of samples are respectively obtained from the plurality of acoustic signals. A block reading means for reading as an acoustic block, a frequency converting means for performing a Fourier transform on the read acoustic block to generate a spectrum block, and corresponding components of the spectrum block obtained from each of the acoustic signals are multiplied. A block synthesizing unit that synthesizes the spectrum blocks by calculating to generate a synthesized spectrum block; a frequency inverse transform unit that performs Fourier inverse transform on the generated synthesized spectrum block and generates a synthesized acoustic block; Output means for outputting the generated synthesized sound block in time series order Wherein the structure and the.

  According to the present invention, for a plurality of acoustic signals, after frequency analysis of each acoustic signal in a predetermined unit, the obtained frequency components are synthesized with each other, and the frequency components after synthesis are frequency-inverted, Since the acoustic signal is returned to the acoustic signal, the synthesized acoustic signal has an effect of being novel while leaving the influence of each acoustic signal before the synthesis.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(1. Configuration of the synthesizer)
FIG. 1 is a functional block diagram showing a configuration of an acoustic signal synthesizer according to the present invention. In FIG. 1, 10 is a block reading means, 20 is a frequency converting means, 30 is a block synthesizing means, 40 is an inverse frequency converting means, 50 is an output means, 60 is a storage means, 61 is an acoustic signal storage section, and 62 is a synthetic sound. It is a signal storage unit.

  The block reading means 10 has a function of reading a predetermined number of samples as one block from each original acoustic signal to be synthesized. The frequency conversion means 20 has a function of generating a spectrum block by Fourier transforming the block of the acoustic signal read by the block reading means 10. The block synthesizing unit 30 has a function of synthesizing the spectrum blocks obtained for each acoustic signal to generate one synthesized spectrum block. The frequency inverse transform means 40 has a function of generating one synthesized acoustic block by performing Fourier inverse transform on the obtained synthesized spectrum block. The output unit 50 has a function of sequentially outputting the obtained synthesized sound block. The storage unit 60 includes an acoustic signal storage unit 61 that stores a plurality of acoustic signals to be synthesized, and a synthesized acoustic signal storage unit 62 that stores a synthesized acoustic signal after synthesis, and is necessary for other processing. Various types of information are stored. Each component shown in FIG. 1 is actually realized by installing a dedicated program in hardware such as a computer and its peripheral devices. That is, the computer executes the contents of each means according to a dedicated program.

(2.1. Processing operation of synthesizer)
Next, the processing operation of the acoustic signal synthesizer shown in FIG. 1 will be described. The present invention synthesizes two or more acoustic signals. In the following example, a case where two acoustic signals are synthesized will be described as the simplest example. First, the block reading means 10 reads a predetermined number of samples as one acoustic block from two externally designated acoustic signals. An operator designates one as a reference acoustic signal when reading a plurality of acoustic signals. The number of samples of one acoustic block read by the block reading means 10 can be set as appropriate. However, when the sampling frequency is 44.1 kHz, it is desirable to set the number of samples to about 4096 samples. Therefore, the block reading means 10 sequentially reads 4096 samples of the reference sound signal P and the sound signal Q as sound blocks. The acoustic block is read so that the sample overlaps with the adjacent acoustic block. For example, if the first sound block is sample numbers 1 to 4096, the second sound block is sample numbers 2049 to 6144, and the third sound block is sample numbers 4097 to 8192. In this case, in the adjacent sound block, 2048 samples are redundantly encoded. The reason for setting the acoustic block in such a manner that the sections overlap is to prevent noise from occurring at the transition of the acoustic block. In order to prevent the signal level from becoming discontinuous after synthesis for the duplicate samples, a window function is multiplied when performing Fourier transform, as will be described later.

  Subsequently, the frequency conversion means 20 performs a Fourier transform on each read acoustic block to obtain a spectrum block. Specifically, the acoustic signal x (i) is processed according to the following [Equation 1] to obtain a real part A (j) and an imaginary part B (j) of the converted data.

[Formula 1]
A (j) = Σ _{i = 0,} ... _{, N−1} x (i) · cos (2πij / N)
B (j) = Σ _{i = 0,} ... _{, N−1} x (i) · sin (2πij / N)

  In [Expression 1], i is a serial number assigned to N samples in the acoustic block, and takes an integer value of i = 0, 1, 2,... N−1. Further, j is a serial number assigned in order from the smallest value of the frequency value, and takes an integer value of j = 0, 1, 2,. At this time, the acoustic signal x (i) is multiplied by a window function (Hanning window) expressed by W (i) = 0.5−0.5 · cos (2πi / N) as a weight. Such a window function reduces the high-frequency noise generated by dividing the waveform into frequency components when performing the Fourier transform, and the signal level is discontinuous between the analysis intervals when performing the inverse Fourier transform. This is a well-known technique that is used for connection so as not to occur.

  By executing the processing according to the above [Equation 1], a spectrum block expressed by a spectrum which is a component corresponding to a frequency is obtained. Subsequently, the block synthesizing unit 30 performs a process of synthesizing the spectrum block obtained from the reference sound signal P and the spectrum block obtained from the sound signal Q. This synthesizing process is performed by a product operation between the spectrum blocks. Specifically, the real part Ap (j) of the reference acoustic signal P obtained by the above [Formula 1], the real part Aq (j) of the imaginary part Bp (j) acoustic signal Q, and the imaginary part Bq (j) are obtained. Using the following [Equation 2], the real part A ′ (j) and the imaginary part B ′ (j) are calculated as composite values.

[Formula 2]
A ′ (j) = Ap (j) · C {Eq (j) / Ep (j)} ^1/4
B ′ (j) = Bp (j) · C {Eq (j) / Ep (j)} ^1/4
However, Ep (j) = Ap (j) ² + Bp (j) ² , Eq (j) = Aq (j) ² + Bq (j) ²

  In the above [Equation 2], C is a proportional coefficient for amplitude correction and is set as appropriate. Since {Eq (j) / Ep (j)} in the first and second expressions of [Formula 2] is usually a value smaller than 1, the signal level is reduced by multiplication. In order to perform the correction, the proportional coefficient C is multiplied. Therefore, C must be a value greater than 1. Note that the product operation between spectral blocks means that the real part Ap (j) and the imaginary part Bp (j), which are the frequency components of the reference acoustic signal P, are multiplied by the spectral intensity Eq (j) of the acoustic signal Q. Is shown.

  Further, Eq (j) is calculated in units of blocks, but depending on the target acoustic signal, granular noise may occur with subsequent spectrum synthesis processing. This is because spectral discontinuities occur in the time axis direction. As a countermeasure, it is desirable to use an average value of Eq (j) calculated in several blocks near the target block. In this embodiment, the average value of three Eq (j) with Eq (j) calculated in blocks up to two past blocks of the target block is defined as Eq (j), and the first equation of the above [Expression 2] is used. It is used in the formula and the second formula.

  Next, the frequency inverse transform unit 40 performs a process of obtaining a synthesized sound block by performing Fourier inverse transform on the synthesized spectrum block obtained by the synthesis. Specifically, using the real part A ′ (j) and imaginary part B ′ (j) of the spectrum obtained by the above [Equation 2], processing according to the following [Equation 3] is performed, and x ′ (I) is calculated.

[Formula 3]
x ′ (i) = 1 / N · {Σ _{j = 0,} ... _{, N−1 A} ′ (j) · cos (2πij / N) −Σ _{j = 0,} ... _{, N−1 B} ′ (j) • sin (2πij / N)}

  Each sample x ′ (i) of the synthesized sound block is obtained by the above [Equation 3]. The output unit 50 records the obtained synthesized sound block in an output file. By executing the processing as described above over all the samples of the acoustic signal, all the synthesized acoustic blocks are recorded in the output file and obtained as a synthesized acoustic signal. The obtained synthesized acoustic signal is output to and stored in the synthesized acoustic signal storage unit 62 in the storage means 60.

  In the above example, the case of synthesizing two acoustic signals has been described. However, in the case of synthesizing three or more acoustic signals, the following [Equation 1] is used as a generalized equation of [Equation 1] to [Equation 3]. 4] to [Formula 6]. In the following [Equation 4] to [Equation 6], a number k (k = 0, 1, 2,... K−1) is assigned to each of K acoustic signals to be synthesized, and the reference acoustic signal is k. = 0.

[Formula 4]
A (k, j) = Σ _{i = 0,} ... _{, N−1} x (k, i) · cos (2πij / N)
B (k, j) = Σ _{i = 0,} ... _{, N−1} x (k, i) · sin (2πij / N)

  In the above [Formula 4], i, j, and N are the same as those used in the above [Formula 1].

[Formula 5]
A ′ (j) = A (0, j) · C {S (j) / E (0, j)} ^1/4
B ′ (j) = B (0, j) · C {S (j) / E (0, j)} ^1/4
However, S (j) = {E (1, j) · E (2, j) ···· E (K-1, j)} ^{1 / K-1} E (k, j) = A (k, j ) ² + B (k, j) ²

  In the above [Formula 5], the real part A ′ () is used as a composite value by using the real part A (k, j) and imaginary part B (k, j) of each acoustic signal obtained by the above [Formula 4]. j) and the imaginary part B ′ (j) is calculated. In [Formula 5], the correction coefficient C is the same as that used in [Formula 2].

  Further, S (j) is calculated in units of blocks, but depending on the target acoustic signal, granular noise may occur with the subsequent spectrum synthesis process. This is because spectral discontinuity occurs in the time axis direction. As a countermeasure, it is desirable to use an average value of S (j) calculated in several blocks near the target block. In the present embodiment, the average value of three S (j) with S (j) calculated in blocks up to two past blocks of the target block is set to S (j), and the first equation (5) is used. It is used in the formula and the second formula.

  Next, the acoustic signal synthesizer performs a process of obtaining a synthesized acoustic block by performing inverse Fourier transform on the synthesized spectrum block obtained by the synthesis. Specifically, using the real part A ′ (j) and imaginary part B ′ (j) of the spectrum obtained by the above [Formula 5], processing according to the following [Formula 6] is performed, and x ′ (I) is calculated.

[Formula 6]
x ′ (i) = 1 / N · {Σ _{j = 0,} ... _{, N−1 A} ′ (j) · cos (2πij / N) −Σ _{j = 0,} ... _{, N−1 B} ′ (j) • sin (2πij / N)}

  In the above [Equation 6], the real part A ′ (j) and the imaginary part B ′ (j) of the spectrum obtained by the above [Equation 5] are used for each sample constituting the synthesized acoustic signal x ′. (I) is calculated.

(2.2. Processing when performance time of each acoustic signal is different)
When the performance times of the respective acoustic signals k (k = 0, 1, 2,... K-1) to be synthesized are different from each other, there is no problem if the performance time of the reference acoustic signal is short. When the time is long or when it is desired to synchronize the time axes with each other, the following processing is performed.

  First, the number of samples of one block in the reference acoustic signal (k = 0) is set to a value N (0) (for example, 4096) that is a power of 2 in order to apply the fast Fourier transform, and the number of blocks B to be analyzed is calculated. To do. For other acoustic signals (hereinafter referred to as non-reference acoustic signals) other than the reference acoustic signal, the number of samples N (k) that needs to be analyzed once is determined so that the number of blocks is B. When Fourier analysis is performed on a non-reference acoustic signal, N (k) samples are extracted as acoustic blocks, and resampling processing (time axis scaling) is performed so that N (0) samples are obtained. The specific processing of resampling is as follows. For each sample x (k, i) (i = 0,..., N−1) of the non-reference acoustic signal with k ≧ 1, x ″ according to [Equation 7] This processing is executed by obtaining (k, i), which is performed by the block reading means 10.

[Formula 7]
x ″ (k, i) = x (k, INT {i · N (k) / N (0)})

  In the above [Equation 7], INT {} indicates an integer value obtained by rounding down the decimals in {}. This x ″ (k, i) is a resampled sample.

  Subsequently, Fourier transform is performed on the resampled N (0) samples. This is performed by substituting the above x ″ (k, i) in place of x (k, i) in [Formula 4]. Thereafter, the obtained A (k, j) and B (k, i) j) is scaled by N (0) / N (k) with respect to the frequency dimension element consisting of j) to correct the frequency scaling caused by the time base scaling of the acoustic signal. ≧ 1, j = 0,..., N (0) / 2-1 by executing processing according to the following [Equation 8] for the real part and imaginary part components.

[Formula 8]
A ″ (k, j) = A (k, j · N (0) / N (k))
B ″ (k, j) = B (k, j · N (0) / N (k))

  By the above [Equation 8], a spectrum which is a set of corrected frequency components A ″ (k, j) and B ″ (k, j) is obtained. This processing is performed by the frequency conversion means 20. When synthesizing the spectrum, A ″ (k, j) and B ″ (k, j) obtained for each non-acoustic signal are converted into A (k, j) and B (k , J), each frequency component of the combined spectrum block is obtained.

  The acoustic signal synthesizer according to the present invention can perform processing on each channel regardless of whether each acoustic signal is composed of one channel or a plurality of channels. In addition, if the signal level of each channel is different in the original acoustic signal, the frequency component of the spectrum block obtained for each channel is scaled with a different weight for each channel, and the corresponding channels are different. It is synthesized with the acoustic signal. Specifically, scaling is performed on E (k, j) calculated in the above [Equation 5].

(3.1 Configuration of playback device)
Next, a sound signal reproducing apparatus according to the present invention will be described. FIG. 2 is a block diagram showing an embodiment of a sound signal reproducing apparatus according to the present invention. In FIG. 2, 70 is a synthesis block storage means, 80 is a sound device driver, 81 is a sound device, 82 is a timer, and 90 is a synthesis ratio setting means.

  The block reading means 10 to the frequency reverse conversion means 40 are exactly the same as those in the acoustic signal synthesizer shown in FIG. Unlike the output unit 50 shown in FIG. 1, the synthetic block input unit 51 is not the synthetic acoustic signal storage unit 62 but the synthetic block storage unit 70, unlike the output unit 50 shown in FIG. 1. However, the synthesis block input unit 51 not only simply inputs a synthetic sound block, but also has a function of controlling the input of the synthetic sound block when the synthesis block storage unit 70 has no space, as will be described later. ing. The synthesized block storage means 70 has a plurality of buffer memories for storing synthesized acoustic blocks, and the synthesized acoustic blocks stored in these buffer memories are stored in the FIFO (first in first out) method, that is, first in. It has a function to process the received information in a way that goes out first. That is, the synthesized block accumulating unit 70 has a function of accumulating the synthesized sound blocks input from the synthesized block input unit 51 in the input order and passing them to the sound device driver 80 in that order. The sound device driver 80 has a function of driving the sound device 81 to reproduce sound of the synthesized sound block. The sound device 81 performs D / A conversion on the synthesized sound block that is digital data and reproduces it as sound. It has a function. That is, the sound device driver 80 and the sound device 81 function as synthetic sound block reproduction means. The timer 82 is a timer used for timing the reproduction of the acoustic signal by the sound device and the reproduction of the acoustic signal of the external device, and is shared with a timer that performs time management in the computer. The synthesis ratio setting means 90 has a function of setting a ratio at which a plurality of acoustic signals are synthesized.

(3.2 Processing operation of playback device)
Next, the processing operation of the playback device shown in FIG. 2 will be described. First, the user of the playback device sets the synthesis ratio of a plurality of sound signals by the synthesis ratio setting means 90. Specifically, a value corresponding to the proportional coefficient C in the above [Equation 2] is set. The set composition ratio is given from the composition ratio setting means 90 to the block composition means 30.

  After the setting, the acoustic signal reproduction device starts processing. First, the block reading means 10 reads a plurality of acoustic signals in units of blocks. Subsequently, the frequency conversion means 20 converts the acoustic block into a spectrum block.

  Next, the block synthesizing unit 30 synthesizes the spectrum blocks according to the above [Equation 5]. At this time, when the synthesis ratio is set, the ratio set to the spectrum intensity E (k, j) of each acoustic signal is multiplied in calculating the above S (j).

  Subsequently, the frequency inverse transform unit 40 inversely transforms the obtained plurality of spectrum blocks to generate a synthesized acoustic block. The synthesized sound block obtained by the frequency inverse transform means 40 is accumulated in the synthesized block accumulation means 70 by the synthesis block input means 51. In the present embodiment, since up to 4 blocks can be stored in the synthesized block storage unit 70, processing by the sound device driver 80 is not started until 4 blocks are stored. As shown in FIG. 3, when four synthesized sound blocks are accumulated in the synthesized block accumulating unit 70, the sound device driver 80 reproduces the first block among the synthesized acoustic blocks accumulated in the synthesized block accumulating unit 70. To do. Specifically, the sound device 81 D / A converts the data of the synthesized sound block and outputs it to the speaker. The synthesized sound block that has been reproduced is deleted from the synthesized block storage means 70.

  When the synthesized sound block is deleted and there is room in the synthesized block storage unit 70, the synthesized block is put into the synthesized block storage unit 70 from the synthesized block input unit 51. As a result, the combined block storage means 70 is stored up to the maximum capacity again. The synthesized synthesized sound block is actually put into the synthesized block accumulating means 70 when the CPU functions as the synthesized block throwing means 51. This synthetic block input means 51 not only simply inputs the synthetic sound block to the synthetic block storage means 70, but also when the synthetic block storage means 70 has no free space, the block reading means 10, the frequency conversion means 20, the block synthesis. A message for interrupting the processing is sent to the means 30 and the frequency inverse transform means 40 to control the input of the synthesized sound block to the synthesized block storage means 70.

  On the other hand, the sound device driver 80 sequentially plays back the first block among the synthesized sound blocks stored in the synthesized block storing means 70. At this time, each time the sound device driver 80 finishes the sound reproduction of one synthesized sound block, the sound reading is performed by the block reading means 10, the frequency converting means 20, the block synthesizing means 30, the frequency inverse converting means 40, and the synthesized block input means 51. A message that permits execution of each process is sent to the server.

  Here, the outline of the processing in the reproducing apparatus is organized and shown in the flowchart of FIG. First, the composite block input unit 51 searches for a free buffer memory in the composite block storage unit 70 (step S1). If there is no free buffer memory, a message for interrupting the process is sent to the block reading means 10, the frequency converting means 20, the block synthesizing means 30, the frequency inverse converting means 40, and the synthesizing block input means 51, and the sound device A reception end message is waited for from the driver 80 (step S2). If there is a playback end message from the sound device driver 80, the playback end buffer is set as an empty buffer by deleting from the buffer memory storing the synthesized sound block that has been played back (step S3). Since the reproduction end message from the sound device driver 80 is simultaneously transmitted to the block reading means 10, the frequency converting means 20, the block synthesizing means 30, the frequency reverse converting means 40, and the synthesized block inputting means 51, the block reading means 10, The frequency conversion unit 20, the block synthesis unit 30, the frequency inverse conversion unit 40, and the synthesis block input unit 51 resume processing, and the synthesis of the acoustic signal is performed (step S4). Subsequently, the synthesized sound block is stored in an empty buffer memory (step S5). On the other hand, the sound device 81 always searches for the buffer memory in the synthetic block storage means 70 (step S6), and when the synthetic acoustic block exists, the synthetic acoustic block is reproduced (step S7). Waiting for the reproduction of one synthesized sound block (step S8), when the reproduction is completed, a reproduction end message is sent to the block reading means 10, the frequency converting means 20, the block synthesizing means 30, the frequency reverse converting means 40, and the synthetic block input means 51. Transmit (step S9).

It is a functional block diagram of the synthesis apparatus of the acoustic signal which concerns on this invention. It is a functional block diagram of the synthetic | combination reproduction | regeneration apparatus of the acoustic signal which concerns on this invention. It is a figure which shows the synthetic | combination reproduction | regeneration apparatus of the acoustic signal of the state in which the synthetic | combination acoustic block was accumulate | stored. It is a flowchart which shows the processing operation of the synthetic | combination reproduction | regeneration apparatus of an acoustic signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Block reading means 20 ... Frequency conversion means 30 ... Block synthesis means 40 ... Frequency reverse conversion means 50 ... Output means 51 ... Synthesis block input means 60 ... Storage means 61 ... Acoustic signal storage unit 62 ... Synthetic acoustic signal storage unit 70 ... Synthetic block storage means 80 ... Sound device driver 81 ... Sound device 82 ... Timer 90 ... Synthesis ratio setting means

Claims (11)

A device for synthesizing a plurality of acoustic signals composed of time-series sample sequences to generate a synthesized acoustic signal,
A block reading means for reading a predetermined number of samples as acoustic blocks from a plurality of acoustic signals,
Frequency transforming means for performing Fourier transform on the read acoustic block and generating a spectrum block;
Block synthesis means for synthesizing spectrum blocks to generate a synthesized spectrum block by performing a product operation on the corresponding components of the spectrum blocks obtained from the respective acoustic signals;
Frequency inverse transform means for performing inverse Fourier transform on the generated synthesized spectrum block and generating a synthesized acoustic block;
Output means for outputting the generated synthesized sound block in chronological order;
An apparatus for synthesizing an acoustic signal, comprising: In claim 1,
The block reading means reads the acoustic block by overlapping a predetermined number of samples on the time axis in the acoustic signal, and changes the value of the sample in the acoustic block read by a predetermined weight function. An apparatus for synthesizing acoustic signals. In claim 1,
The block synthesizing unit synthesizes the spectrum blocks by using an average value of corresponding components of one or more spectrum blocks located in the past in time from the spectrum blocks obtained from the respective acoustic signals. An apparatus for synthesizing an acoustic signal. In claim 1,
The block reading means reads the sound block with a different number of samples for each sound signal as one sound block so that the number of blocks is the same for each sound signal, and then reads one of the plurality of sound signals. A process for deleting a part of the samples in the acoustic block in order to make the other acoustic signal coincide with the number of samples of the acoustic block of the reference acoustic signal, as a reference acoustic signal,
The frequency conversion means performs a Fourier transform on the acoustic block from which some samples are deleted, and performs a scaling process in the frequency axis direction on the obtained spectrum block,
The apparatus for synthesizing an acoustic signal characterized in that the block synthesizing means performs processing on a spectrum block that has been subjected to scaling processing in the frequency axis direction. In claim 1,
The block synthesizing unit synthesizes the frequency component of the spectrum block obtained from each acoustic signal by scaling based on the weight set in advance for each acoustic signal. Synthesizer. In claim 5,
The block synthesizing means, when each acoustic signal is composed of a plurality of channels,
An apparatus for synthesizing an acoustic signal, characterized in that the frequency component of a spectrum block obtained for each channel is scaled with a different weight for each channel. A device that synthesizes a plurality of sound signals composed of time-series sample sequences and reproduces the sound,
A block reading means for reading a predetermined number of samples as acoustic blocks from a plurality of acoustic signals,
Frequency transforming means for performing Fourier transform on the read acoustic block and generating a spectrum block;
Block synthesis means for synthesizing spectrum blocks to generate a synthesized spectrum block by performing a product operation on the corresponding components of the spectrum blocks obtained from the respective acoustic signals;
Frequency inverse transform means for performing inverse Fourier transform on the generated synthesized spectrum block and generating a synthesized acoustic block;
Synthetic block accumulating means for accumulating two or more synthetic acoustic blocks;
Synthetic block input means for inputting the generated synthetic acoustic block into the synthetic block storage means;
Of the synthesized sound blocks existing in the synthesized block storage means, the first synthesized sound block is played back, and after the playback is finished, the synthesized sound block is deleted from the synthesized block storage means, so that a new synthesized sound block is obtained. In addition to providing room for the block to be inserted in the synthetic block accumulating unit, if there is a synthetic acoustic block stored next, the next synthetic acoustic block is acoustically connected to the first synthetic acoustic block. Synthetic block reproduction means for reproducing;
An apparatus for synthesizing and reproducing acoustic signals, comprising: In claim 7,
When the synthetic block input means inputs a synthetic acoustic block,
When the synthesized block storage means cannot afford to newly accept a synthesized sound block, a message for interrupting each operation is sent to the block reading means, the frequency converting means, the block synthesizing means, and the frequency inverse converting means. The sound signal reproducing apparatus is characterized in that each of the means performs control to be interrupted in a current state. In claim 7,
Each time the synthetic block reproducing means finishes reproducing one synthetic acoustic block, the block reading means, the frequency converting means, the block synthesizing means, and the frequency inverse converting means are interrupted by the respective means. An apparatus for reproducing an acoustic signal, wherein control for resuming an operation is resumed. On the computer,
A block reading means for reading a predetermined number of samples as acoustic blocks from a plurality of acoustic signals,
Frequency conversion means for performing Fourier transform on the read acoustic block and generating a spectrum block,
Block synthesizing means for synthesizing spectrum blocks to generate a synthesized spectrum block by multiplying corresponding components of the spectrum blocks obtained from the respective acoustic signals;
Frequency inverse transform means for performing inverse Fourier transform on the generated synthesized spectrum block and generating a synthesized acoustic block;
A computer program for executing output means for outputting the generated synthetic sound block in time series order. On the computer,
Block reading means for reading a predetermined number of samples as acoustic blocks from a plurality of acoustic signals,
Frequency conversion means for performing Fourier transform on the read acoustic block and generating a spectrum block,
Block synthesizing means for synthesizing spectrum blocks to generate a synthesized spectrum block by multiplying corresponding components of the spectrum blocks obtained from the respective acoustic signals,
Frequency inverse transform means for performing inverse Fourier transform on the generated synthesized spectrum block and generating a synthesized acoustic block;
Synthetic block accumulating means for accumulating two or more synthetic acoustic blocks;
Synthetic block input means for inputting the generated synthetic acoustic block into the synthetic block storage means;
Of the synthesized sound blocks existing in the synthesized block storage means, the first synthesized sound block is played back, and after the playback is finished, the synthesized sound block is deleted from the synthesized block storage means, so that a new synthesized sound block is obtained. In addition to providing the synthetic block accumulating means with a room where a block can be inserted, if there is a synthetic acoustic block stored next, the next synthetic acoustic block is continuously acoustically connected to the first synthetic acoustic block. A computer program for executing synthetic block reproduction means for reproduction.

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