JP6554769B2 - Acoustic signal processing device - Google Patents

Description

  The present invention relates to an acoustic signal processing device that adjusts the level of an acoustic signal.

  A dynamic range of an acoustic signal is compressed so as to suppress a level (amplitude) of a signal component exceeding a preset threshold value (see, for example, Patent Document 1). Such dynamic range compression is performed on the sound signals of individual instrument sounds (individual tracks) or finally mixed sound signals. The dynamic range is compressed to increase the sound density audibly. For this reason, dynamic range compression is actively used to impart musicality to acoustic signals. Hereinafter, a method of compressing the level of the signal component of the entire band of the acoustic signal based on a parameter such as a set threshold value is referred to as single-band compression.

  In recent years, various techniques for dividing an acoustic signal into signal components of a plurality of bands and compressing the signal components for each band have been developed (see, for example, Patent Document 2). Hereinafter, a method of dividing an acoustic signal into signal components of a plurality of bands and compressing the signal component level of each band based on parameters such as a set threshold value is referred to as multiband compression. According to multiband compression, the level of a large signal component in a specific band can be efficiently compressed without affecting the signal components in other bands.

Japanese Patent Laid-Open No. 3-218109 JP 2012-1000019

  The present inventor has paid attention to the fact that according to the single band compression, a specific acoustic effect is obtained in which the sound of the other band is modulated according to the change of the sound of each band. In addition, the inventor has paid attention to the fact that, according to multiband compression, large dynamics can be imparted to an acoustic signal. And the structure which gives various acoustic effects to an acoustic signal without unnaturalness was considered.

  An object of the present invention is to provide an acoustic signal processing apparatus capable of imparting various acoustic effects to an acoustic signal without causing unnaturalness.

(1) An acoustic signal processing device according to the present invention is an acoustic signal processing device that generates an output acoustic signal by adjusting a level of an input acoustic signal, and a band that divides the input acoustic signal into signal components of a plurality of bands. Dividing means, setting means for setting a plurality of first parameters corresponding to a plurality of bands and a second parameter corresponding to a single band including the plurality of bands, and levels of signal components in the plurality of bands And a plurality of first adjustment value generating means for generating a plurality of first adjustment values based on the plurality of first parameters, and a first band based on the level of the signal component of the single band and the second parameter. a second adjustment value generation means for generating a second adjustment value to adjust the level of the signal components of the plurality of bands based on the plurality of first adjustment value, a single band on the basis of the second adjustment value Adjust the signal component level of It includes a level adjusting unit, and a sound signal generating means for generating an output sound signal based on the signal component which is adjusted by the level adjusting means, setting means, one adjustment of the first and second parameters Thus, the first parameter and the second parameter are interlocked so that the other changes complementarily.

  In the acoustic signal processing device, the levels of signal components in a plurality of bands or a single band are adjusted based on the plurality of first adjustment values and the second adjustment value, respectively. Here, the plurality of first adjustment values are generated based on the levels of the signal components in the plurality of bands and the plurality of first parameters, respectively. Adjustment of the level of the signal component by the plurality of first adjustment values is referred to as multiband adjustment. In multiband adjustment, signal components in each band are not affected by signal components in other bands. Thereby, it becomes possible to give large dynamics. The second adjustment value is generated based on the level of the signal component of a single band including a plurality of bands and the second parameter. Adjustment of the level of the signal component by the second adjustment value is referred to as single band adjustment. In the single band adjustment, a specific acoustic effect is obtained by mutually modulating signal components in various bands. In this case, each first parameter and the second parameter are interlocked so that the other of the first parameter and the second parameter changes in a complementary manner by adjustment. “Complementarily changing” means that when one increases, the other decreases, and when one decreases, the other increases. This prevents the level of the output acoustic signal from being unnaturally adjusted as a whole. As a result, various acoustic effects can be imparted to the acoustic signal without unnaturalness.

(2) The plurality of first adjustment value generation means respectively generate a plurality of first adjustment coefficients based on the levels of the signal components in the plurality of bands, and generate the plurality of first adjustment coefficients and the plurality of first adjustment coefficients. A plurality of first adjustment values are generated based on one parameter, and the second adjustment value generation means is a total value of the plurality of first adjustment coefficients generated by the plurality of first adjustment value generation means or The second adjustment value is generated based on the minimum value and the second parameter , and the level adjustment means is based on a plurality of addition values obtained by adding the second adjustment value to each of the plurality of first adjustment values. The level of the signal component of each of the plurality of bands may be adjusted, and the acoustic signal generation unit may generate the output acoustic signal by combining the signal components of the plurality of bands adjusted by the level adjustment unit.

  In this case, since the second adjustment value is generated based on the plurality of first adjustment coefficients generated by the first adjustment value generation unit, the configuration of the second adjustment value generation unit is simplified. Thereby, it is possible to reduce the calculation amount and the cost.

( 3 ) The second adjustment value generation means generates a second adjustment coefficient based on the level of the signal component of the single band, and the second adjustment value generation means generates the second adjustment coefficient based on the generated second adjustment coefficient and the second parameter. The adjustment value may be generated.

  In this case, since the second adjustment value is generated based on the second adjustment coefficient different from the plurality of first adjustment coefficients and the second parameter, the level of the entire band of the input sound signal is output as the output sound. It is possible to sufficiently reflect the level of the signal component of each band in the signal.

( 4 ) The second adjustment value generation means generates a second adjustment coefficient based on the level of the input acoustic signal, and the level adjustment means applies the second adjustment value to each of the plurality of first adjustment values . The level of each signal component of the plurality of bands is adjusted based on the added value , and the acoustic signal generation unit generates an output acoustic signal by synthesizing the signal components of the plurality of bands adjusted by the level adjustment unit. May be.

In this case, multiband adjustment by the plurality of first adjustment value generation means and single band adjustment by the second adjustment value generation means are performed in parallel on the input acoustic signal. Thereby, it is possible to accurately control the level of the signal components in the entire band. In addition, after the adjustment using the first adjustment value and the second adjustment value is performed on each signal component of the plurality of bands, the plurality of adjusted signal components are synthesized. Thereby, the single band adjustment can be sufficiently reflected in the signal component of each band.
(5) The level adjustment means includes a plurality of first multipliers for adjusting the levels of signal components in a plurality of bands based on the plurality of first adjustment values, and a single band based on the second adjustment values. A second multiplier for adjusting the level of the signal component.
(6) The level adjustment means includes a plurality of multipliers that adjust the level of each signal component in the plurality of bands based on a plurality of addition values obtained by adding the second adjustment value to each of the plurality of first adjustment values. May be included.

  According to the present invention, various acoustic effects can be imparted to an acoustic signal without unnaturalness.

It is a block diagram which shows the structure of the acoustic signal processing apparatus which concerns on 1st Embodiment. It is a figure which shows the function which calculates | requires a compression coefficient from a signal level. It is a schematic diagram which shows an example of an operation part, and another example. 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. It is a block diagram which shows the structure of the acoustic signal processing apparatus which concerns on 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(1) First Embodiment FIG. 1 is a block diagram showing a configuration of an acoustic signal processing device according to a first embodiment. The acoustic signal processing device 1 in FIG. 1 functions as a sound effect applying device (compressor) that compresses the dynamic range of the input acoustic signal SI. The input sound signal SI is a sample series indicating a time waveform of sound such as voice or musical sound. The acoustic signal processing device 1 includes a band dividing unit 10, a plurality of adjustment value generation units 21 to 23, an adjustment value generation unit 30, a synthesis unit 40, a plurality of multipliers 51 to 53, and a ratio setting unit 100.

  The band dividing unit 10 includes a plurality of band pass filters 11 to 13. In this example, the band pass filter 11 is a low pass filter (LPF), the band pass filter 12 is a band pass filter (BPF), and the band pass filter 13 is a high pass filter (HPF). The bandpass filters 11 to 13 are provided with the input acoustic signal SI. The band pass filter 11 extracts and outputs a signal component S1 in a frequency band lower than the first frequency (hereinafter referred to as a first band) from the input acoustic signal SI. The band pass filter 12 extracts and outputs a signal component S2 of a frequency band (hereinafter referred to as a second band) that is equal to or higher than the first frequency and equal to or lower than the second frequency from the input acoustic signal SI. The band pass filter 13 extracts and outputs a signal component S3 in a frequency band higher than the second frequency (hereinafter referred to as a third band) from the input acoustic signal SI.

  In the adjustment value generating units 21 to 23 and 30, a threshold value, an attack time, a release time, and a ratio are set as variable parameters. The attack time is the time from when the level of the signal component reaches the threshold until the actual compression starts. The release time is the time from when the level of the signal component after compression falls below the threshold value until it returns to the level before compression. The ratio is a ratio representing the degree of compression.

  The signal component S1 output from the bandpass filter 11 is supplied to the multiplier 51 and to the adjustment value generation unit 21. The adjustment value generation unit 21 includes a threshold value setting unit 2a, a full wave rectification unit 2b, an attack / release setting unit 2c, a gain adjustment unit 2d, and a ratio adjustment unit 2e. In FIG. 1, the threshold value setting unit 2a is expressed as “THD”, the full wave rectification unit 2b is expressed as “AWD”, and the attack / release setting unit 2c is expressed as “A / R”. The gain adjusting unit 2d is expressed as “GR”, and the ratio adjusting unit 2e is expressed as “RA”.

  In the threshold setting unit 2a, a threshold TH1 adjusted by the user using the operation unit 110 of FIG. The threshold value setting unit 2a determines whether or not the level of the signal component S1 exceeds the set threshold value TH1. The full wave rectification unit 2b performs full wave rectification on the signal component S1. In the attack / release setting unit 2c, the attack time A1 and the release time R1 adjusted using the operation unit 110 of FIG. 3 are set. The attack / release setting unit 2c activates the gain adjusting unit 2d when the attack time A1 has elapsed from the time when the level of the signal component S1 exceeds the threshold value TH1. The attack / release setting unit 2c stops the gain adjusting unit 2d when the release time R1 has elapsed from the time when the level of the signal component S1 falls below the threshold value TH1. The gain adjusting unit 2d stores a function for obtaining a compression coefficient from the signal level in advance.

  FIG. 2 is a diagram showing a function for obtaining a compression coefficient from the signal level. In FIG. 2A, the horizontal axis indicates the signal level (signal component level) by a value in the linear region, and the vertical axis indicates the compression coefficient by a value in the linear region. The horizontal axis in FIG. 2B indicates the signal level as a logarithmic value (decibel value), and the vertical axis indicates the compression coefficient as a logarithmic value (decibel value). In the function of FIG. 2A, when the signal level is equal to or lower than the threshold value, the value of the compression coefficient is 1 and constant. When the signal level exceeds the threshold value, the value of the compression coefficient decreases nonlinearly. In the function of FIG. 2B, when the signal level is equal to or lower than the threshold value, the value of the compression coefficient is constant at 0 [dB]. When the signal level exceeds the threshold, the value of the compression factor decreases linearly.

  In the present embodiment, the gain adjusting unit 2d in FIG. 1 acquires the compression coefficient c1 corresponding to the signal component S1 from the function in FIG. Specifically, the gain adjusting unit 2d acquires 1 as the compression coefficient c1 when the level of the signal component S1 is equal to or less than the threshold value TH1, and when the level of the signal component S1 exceeds the threshold value TH1, the compression coefficient A value smaller than 1 is acquired as c1. As the excess amount from the threshold value TH1 increases, the compression coefficient c1 decreases.

  In the ratio adjuster 2e of FIG. 1, a ratio Ra1 'is set by a ratio setting unit 100 described later. The ratio adjustment unit 2e adjusts the compression coefficient c1 acquired by the gain adjustment unit 2d based on the set ratio Ra1 ', and supplies the adjusted compression coefficient to the multiplier 51 as the adjustment value C1. Specifically, the ratio adjustment unit 2e adjusts the compression coefficient so that the larger the ratio Ra1 'is, the larger the slope of the part exceeding the threshold value of the function in FIG. In the example of FIG. 2A, when the ratio Ra1 ′ is small, the slope of the compression coefficient is as small as a solid line, and as the ratio Ra1 ′ increases, the slope of the compression coefficient becomes a broken line, a one-dot chain line, and a two-dot chain line. As shown in

  The multiplier 51 of FIG. 1 multiplies the signal component S1 provided from the band pass filter 11 by the adjustment value C1 provided from the adjustment value generation unit 21. The adjustment value C1 becomes smaller than 1 when the signal component S1 exceeds the threshold value TH1. Thereby, the level of the signal component S1 exceeding the threshold value TH1 is compressed. The multiplication result of the multiplier 51 is given to the synthesis unit 40 as a signal component S1 '.

  The signal component S2 output from the band pass filter 12 is supplied to the multiplier 52 and to the adjustment value generation unit 22. The configuration and operation of the adjustment value generation unit 22 are the same as those of the adjustment value generation unit 21. The threshold value TH2 adjusted using the operation unit 110 of FIG. 3 is set in the threshold value setting unit 2a of the adjustment value generating unit 22, and the attack time A2 and the release time R2 are set in the attack / release setting unit 2c. The The gain adjusting unit 2d outputs a compression coefficient c2. In the ratio adjusting unit 2e, a ratio Ra2 'is set by a ratio setting unit 100 described later. The adjustment value C2 is given to the multiplier 52 by the ratio adjustment unit 2e of the adjustment value generation unit 22. The multiplier 52 multiplies the signal component S2 provided from the bandpass filter 12 by the adjustment value C2 provided from the adjustment value generation unit 22, and provides the multiplication result to the synthesis unit 40 as the signal component S2 '.

  The signal component S3 output from the band pass filter 13 is supplied to the multiplier 53 and also to the adjustment value generation unit 23. The configuration and operation of the adjustment value generation unit 23 are the same as those of the adjustment value generation unit 21. The threshold value TH3 adjusted using the operation unit 110 of FIG. 3 is set in the threshold value setting unit 2a of the adjustment value generation unit 23, and the attack time A3 and the release time R3 are set in the attack / release setting unit 2c. The The gain adjusting unit 2d outputs a compression coefficient c3. In the ratio adjusting unit 2e, a ratio R3 'is set by a ratio setting unit 100 described later. The adjustment value C3 is given to the multiplier 53 by the ratio adjustment unit 2e of the adjustment value generation unit 23. The multiplier 53 multiplies the signal component S3 given from the band pass filter 13 by the adjustment value C3 given from the adjustment value generation unit 23, and gives the multiplication result to the synthesis unit 40 as the signal component S3 '.

  The synthesizer 40 synthesizes the signal components S1 to S3 given from the multipliers 51 to 53, thereby generating a synthesized acoustic signal SF for the entire band. The synthesized acoustic signal SF generated by the synthesizer 40 is supplied to the multiplier 50 and to the adjustment value generator 30. The band division unit 10, the adjustment value generation units 21 to 23, the synthesis unit 40, and the multipliers 51 to 53 compress the levels of the signal components S1 to S3 in the first to third bands based on the adjustment values C1 to C3, respectively. Multiband compression (MBC) is performed. According to multiband compression, the level of signal components in each band does not affect the level of signal components in other bands, so that large dynamics can be imparted to the input acoustic signal SI.

  The adjustment value generation unit 30 includes a threshold value setting unit 3a, a full wave rectification unit 3b, an attack / release setting unit 3c, a gain adjustment unit 3d, and a ratio adjustment unit 3e. The configuration and operation of the adjustment value generation unit 30 are the same as those of the adjustment value generation unit 21. The threshold value TH0 adjusted using the operation unit 110 of FIG. 3 is set in the threshold value setting unit 3a, and the attack time A0 and the release time R0 are set in the attack / release setting unit 3c. The gain adjusting unit 3d outputs a compression coefficient c0. In the ratio adjusting unit 3e, a ratio Ra0 'is set by a ratio setting unit 100 described later. An adjustment value C0 is given to the multiplier 50 by the ratio adjustment unit 3e.

  Multiplier 50 multiplies synthesized acoustic signal SF given from synthesizing unit 40 by adjustment value C0 given from adjustment value generating unit 30, and outputs the multiplication result as output acoustic signal SO. The adjustment value generation unit 30 and the multiplier 50 perform single band compression (SBC) that compresses the level in the entire band of the synthesized acoustic signal SF based on the adjustment value C0. According to the single band compression, a specific acoustic effect can be obtained by mutually modulating signal components of a plurality of bands.

  FIG. 3A is a schematic diagram illustrating an example of the operation unit 110, and FIG. 3B is a schematic diagram illustrating another example of the operation unit 110. The operation unit 110 shown in FIG. 3A includes adjustment knobs V11 to V13 for adjusting threshold values TH1 to TH3 in multiband compression (MBC), and adjustment knobs V21 to V3 for adjusting attack times A1 to A3. Adjustment knobs V31 to V33 for adjusting V23, release times R1 to R3 and adjustment knobs V41 to V43 for adjusting the ratios Ra1 to Ra3 are provided. The operation unit 110 also includes an adjustment knob V10 for adjusting the threshold value TH0 in single band compression (SBC), an adjustment knob V20 for adjusting the attack time A0, and an adjustment knob V30 for adjusting the release time R0. And an adjustment knob V40 for adjusting the ratio Ra0.

  The operation unit 110 in FIG. 3B is different from the operation unit 110 in FIG. 3A in that it further includes an adjustment knob V50 for adjusting the balance BAL between the multiband compression and the single band compression.

  Here, a first operation example of the ratio setting unit 100 of FIG. 1 will be described. In the first operation example, the ratio setting unit 100 in FIG. 1 is provided with the ratios Ra1 to Ra3 and the ratio Ra0 adjusted using the operation unit 110 in FIG. The ratio setting unit 100 calculates multiband compression ratios Ra1 'to Ra3' according to the following equations (1) to (4).

Ra1 ′ = Ra1-Ra0 (1)
Ra2 ′ = Ra2-Ra0 (2)
Ra3 ′ = Ra3-Ra0 (3)
Ra0 ′ = Ra0 (4)
The calculated multiband compression ratios Ra1 ′ to Ra3 ′ are set in the ratio adjustment units 2e of the adjustment value generation units 21 to 23, respectively. Further, the ratio Ra0 adjusted using the operation unit 110 is set in the ratio adjustment unit 3e of the adjustment value generation unit 30 as it is as the single-band compression ratio Ra0 ′. In this case, when the ratio Ra0 ′ of the single band compression increases, the ratios Ra1 ′ to Ra3 ′ of the multiband compression decrease. Conversely, when the single-band compression ratio Ra0 ′ decreases, the multi-band compression ratios Ra1 ′ to Ra3 ′ increase. Thus, the ratio Ra0 ′ of the single band compression and the ratios Ra1 ′ to Ra3 ′ of the multiband compression are linked so as to change complementarily. Accordingly, it is possible to prevent the input acoustic signal SI from being excessively compressed by the multiband compression and the single band compression.

  Next, a second operation example of the ratio setting unit 100 in FIG. 1 will be described. In the second operation example, the ratio setting unit 100 in FIG. 1 is provided with the ratios Ra1 to Ra3, the ratio Ra0, and the balance BAL adjusted using the operation unit 110 in FIG. The ratio setting unit 100 calculates the ratios Ra1 'to Ra3' of the multiband compression and the ratio Ra0 'of the single band compression according to the following formulas (5) to (8).

Ra1 ′ = (1-BAL) × Ra1 (5)
Ra2 ′ = (1-BAL) × Ra2 (6)
Ra3 ′ = (1-BAL) × Ra3 (7)
Ra0 ′ = BAL × Ra0 (8)
Here, the balance BAL is an arbitrary value between 0 and 1. The calculated multiband compression ratios Ra1 ′ to Ra3 ′ are set in the ratio adjustment units 2e of the adjustment value generation units 21 to 23, respectively. Further, the calculated ratio Ra0 ′ of the single band compression is set in the ratio adjustment unit 3e of the adjustment value generation unit 30. In this case, when the balance BAL is increased, the multiband compression ratios Ra1 ′ to Ra3 ′ are decreased, and the single band compression ratio Ra0 ′ is increased. Conversely, when the balance BAL decreases, the multiband compression ratios Ra1 ′ to Ra3 ′ increase, and the single band compression ratio Ra0 ′ decreases. Thus, the ratio Ra0 ′ of the single band compression and the ratios Ra1 ′ to Ra3 ′ of the multiband compression are linked so as to change complementarily. Accordingly, it is possible to prevent the input acoustic signal SI from being excessively compressed by the multiband compression and the single band compression. The user can easily and intuitively adjust the ratio between the multi-band compression and the single-band compression using the adjustment knob V50.

  In the acoustic signal processing device 1 according to the present embodiment, multi-band compression is performed on the input acoustic signal SI, and single-band compression is performed on the synthesized acoustic signal SF on which the multi-band compression is performed. Thereby, the dynamic effect by a multiband compression and the acoustic effect peculiar to a single band compression are acquired. In this case, since the multiband compression ratios Ra1 ′ to Ra3 ′ and the singleband compression ratio Ra0 ′ change in a complementary manner, the level of the output acoustic signal SO is prevented from being unnaturally adjusted as a whole. . As a result, it is possible to easily obtain the output acoustic signal SO to which various acoustic effects are imparted without causing unnaturalness.

(2) Second Embodiment FIG. 4 is a block diagram showing a configuration of an acoustic signal processing device according to a second embodiment. The acoustic signal processing device 1 in FIG. 4 is different from the acoustic signal processing device 1 in FIG. 1 in the following points. The acoustic signal processing apparatus 1 in FIG. 4 includes a multiplier 50a instead of the multiplier 50 in FIG.

  The input acoustic signal SI is given to the band dividing unit 10 and the threshold value setting unit 3a of the adjustment value generating unit 30. The adjustment value CS is output from the ratio adjustment unit 3e of the adjustment value generation unit 30. Multiplier 50a multiplies synthesized acoustic signal SF output from synthesizing unit 40 by adjustment value CS output from adjustment value generating unit 30, and outputs the multiplication result as output acoustic signal SO.

  In the acoustic signal processing device 1 according to the present embodiment, the band dividing unit 10, the adjustment value generation units 21 to 23, the synthesis unit 40, and the multipliers 51 to 53 are based on the adjustment values C1 to C3. Multiband compression is performed to compress the levels of the signal components S1 to S3 in the three bands. In addition, the adjustment value generation unit 30 and the multipliers 51 to 53 perform single band compression that compresses the level in the entire band of the input acoustic signal SI based on the adjustment value CS. In this case, since the multiband compression and the single band compression are performed in parallel with respect to the input acoustic signal SI, it is possible to accurately control the level of the signal components in the entire band. As a result, it is possible to easily and accurately obtain the output acoustic signal SO to which various acoustic effects are imparted without causing unnaturalness.

(3) Third Embodiment FIG. 5 is a block diagram showing a configuration of an acoustic signal processing device according to a third embodiment. The acoustic signal processing device 1 of FIG. 5 differs from the acoustic signal processing device 1 of FIG. 4 in the following points. In the acoustic signal processing device 1 of FIG. 5, a logarithmic conversion unit 2 f is provided between the attack / release setting unit 2 c and the gain adjustment unit 2 d of the adjustment value generation units 21 to 23. The logarithmic conversion unit 2f converts the signal components S1 to S3 into logarithmic domain values (decibel values) (logarithmic conversion). In FIG. 5, a logarithmic conversion unit 2 f and a logarithmic conversion unit 3 f described later are represented as “LOG”.

  The gain adjusting unit 2d of the adjustment value generating units 21 to 23 obtains logarithmic domain compression coefficients c1 'to c3' corresponding to the logarithmically transformed signal components S1 to S3 from the function of Fig. 2B. The ratio adjusting unit 2e of the adjustment value generating units 21 to 23 adjusts the compression coefficients c1 ′ to c3 ′ based on the ratios Ra1 ′ to Ra3 ′, and uses the adjusted values as logarithmic domain adjustment values C1 ′ to C3 ′. Output each. Further, adders 61 to 63 and exponent conversion units 271 to 273 are provided between the adjustment value generating units 21 to 23 and the multipliers 51 to 53, respectively.

  Between the attack / release setting unit 3c and the gain adjustment unit 3d of the adjustment value generation unit 30, a logarithmic conversion unit 3f that performs logarithmic conversion of the input acoustic signal SI that has been full-wave rectified is provided. The gain adjustment unit 3d of the adjustment value generation unit 30 obtains a logarithmic domain compression coefficient c0 'corresponding to the logarithmically transformed input acoustic signal SI from the function of Fig. 2B. The ratio adjuster 3e of the adjustment value generator 30 adjusts the compression coefficient c0 'based on the ratio Ra0', and outputs the adjusted value as the logarithmic domain adjustment value CS '.

  The adders 61 to 63 add the adjustment values C1 'to C3' output from the adjustment value generation units 21 to 23 and the adjustment value CS 'output from the adjustment value generation unit 30, respectively. Exponential conversion units 271 to 273 convert the addition results of adders 61 to 63 into values in the linear region (exponential conversion), and output the exponent-converted values as adjustment values Ce1 to Ce3, respectively. In FIG. 5, the exponent conversion units 271 to 273 are expressed as “EXP”.

  Multipliers 51 to 53 multiply the signal components S1 to S3 output from the bandpass filters 11 to 13 by the adjustment values Ce1 to Ce3 output from the exponent conversion units 271 to 273, and the multiplication results are multiplied by the signal components SM1 to SM3. To the synthesis unit 40. The synthesizer 40 synthesizes the signal components SM1 to SM3 and outputs a synthesized output acoustic signal SO. In the acoustic signal processing device 1 of FIG. 5, since the adjustment values C1 'to C3' and CS change as values in the logarithmic region, the amount of change matches human hearing.

  In the acoustic signal processing device 1 according to the present embodiment, the band dividing unit 10, the adjustment value generation units 21 to 23, the synthesis unit 40, and the multipliers 51 to 53 are mainly based on the adjustment values C1 ′ to C3 ′. Multiband compression is performed to compress the levels of the signal components S1 to S3 in the first to third bands, respectively. Further, mainly the adjustment value generation unit 30, the multipliers 51 to 53, and the adders 61 to 63 perform pseudo single band compression for compressing the level in the entire band of the input acoustic signal SI based on the adjustment value CS '. In this case, since the multiband compression and the single band compression are performed in parallel with respect to the input acoustic signal SI, the levels of the signal components in all the bands can be accurately controlled. As a result, it is possible to easily and accurately obtain the output acoustic signal SO to which various acoustic effects are imparted without causing unnaturalness.

  Further, since the adjustment value CS ′ of the logarithmic domain of the single band compression is added to the adjustment values C1 ′ to C3 ′ of the logarithmic domain of the multiband compression, an expensive exponential conversion unit is provided corresponding to the adjustment value generating unit 30. There is no need. Thereby, the cost can be reduced.

(4) Fourth Embodiment FIG. 6 is a block diagram showing a configuration of an acoustic signal processing device according to a fourth embodiment. The acoustic signal processing device 1 in FIG. 6 is different from the acoustic signal processing device 1 in FIG. 5 in the following points. In the acoustic signal processing device 1 of FIG. 6, the adjustment value generation unit 30 of FIG. 5 is not provided, but the total value calculation unit 34 and the ratio adjustment unit 35 are provided. In FIG. 5, the total value calculation unit 34 is represented by “Σ”.

  The total value calculation unit 34 calculates the total value of the compression coefficients c1 'to c3' output from the gain adjustment unit 2d of the adjustment value generation units 21 to 23, respectively. In the ratio adjustment unit 35, the ratio Ra0 'is set by the ratio setting unit 100. The ratio adjustment unit 35 adjusts the total value calculated by the total value calculation unit 34 based on the set ratio Ra0 ', and outputs the adjusted value as the adjustment value CSa. The adders 61 to 63 add the adjustment values C1 'to C3' output from the adjustment value generation units 21 to 23 and the adjustment value CSa output from the ratio adjustment unit 35, respectively.

  In the acoustic signal processing device 1 according to the present embodiment, the band dividing unit 10, the adjustment value generation units 21 to 23, the synthesis unit 40, and the multipliers 51 to 53 are mainly based on the adjustment values C1 ′ to C3 ′. Multiband compression is performed to compress the levels of the signal components S1 to S3 in the first to third bands, respectively. Further, a pseudo single band in which the total value calculation unit 34, the ratio adjustment unit 35, the multipliers 51 to 53, and the adders 61 to 63 mainly compress the level in the entire band of the input acoustic signal SI based on the adjustment value CSa. Perform compression. In this case, the adjustment value generation unit 30 of FIG. 5 is not necessary, and the amount of calculation and cost can be significantly reduced. As a result, it is possible to easily and accurately obtain the output acoustic signal SO to which various acoustic effects are imparted without causing unnaturalness at low cost.

(5) Fifth Embodiment FIG. 7 is a block diagram showing a configuration of an acoustic signal processing device according to a fifth embodiment. The acoustic signal processing device 1 in FIG. 7 is different from the acoustic signal processing device 1 in FIG. 6 in the following points. In the acoustic signal processing device 1 of FIG. 7, a minimum value selection unit 36 is provided instead of the total value calculation unit 34 of FIG. 6. The minimum value selection unit 36 selects a minimum value from the compression coefficients c1 ′ to c3 ′ output from the gain adjustment unit 2d of the adjustment value generation units 21 to 23, respectively. The ratio adjuster 35 adjusts the minimum value selected by the minimum value selector 36 based on the set ratio Ra0 ′, and outputs the adjusted value as the adjustment value CSb. The adders 61 to 63 add the adjustment values C1 ′ to C3 ′ output from the adjustment value generation units 21 to 23 and the adjustment value CSb output from the ratio adjustment unit 35, respectively.

  In the acoustic signal processing device 1 according to the present embodiment, the band dividing unit 10, the adjustment value generation units 21 to 23, the synthesis unit 40, and the multipliers 51 to 53 are mainly based on the adjustment values C1 ′ to C3 ′. Multiband compression is performed to compress the levels of the signal components S1 to S3 in the first to third bands, respectively. Further, a pseudo single band in which the minimum value selection unit 36, the ratio adjustment unit 35, the multipliers 51 to 53, and the adders 61 to 63 mainly compress the level in the entire band of the input acoustic signal SI based on the adjustment value CSb. Perform compression. In this case, the adjustment value generation unit 30 of FIG. 5 is not necessary, and the amount of calculation and cost can be significantly reduced.

  Further, since the compression amount of the signal component in the single band compression is suppressed, the distortion in the output acoustic signal SO is reduced. Specifically, in single band compression, the same attack time and release time are set for all bands. On the other hand, in multiband compression, an appropriate attack time and release time are set for each band. For example, according to multiband compression, a short attack time and a short release time can be set for the high band, and a long attack time and a long release time can be set for the low band. In this case, the minimum value selection unit 36 selects the minimum compression coefficient in the multiband compression. Thereby, generation | occurrence | production of distortion is suppressed in a single band compression. Therefore, in the output acoustic signal SO, both small distortion and fast response can be achieved. As a result, it is possible to easily and accurately obtain a low distortion output acoustic signal SO to which various acoustic effects are imparted without causing unnaturalness at low cost.

(6) Other Embodiments In the first to fifth embodiments, the band dividing unit 10 is configured by the three band pass filters 11 to 13, but the band dividing unit 10 is two or four. You may comprise the above band pass filter. In this case, the same number of adjustment value generation units as the number of bandpass filters and portions related thereto are provided.

  Instead of the total value calculation unit 34 in FIG. 6, an average value calculation unit that calculates the average value of the compression coefficients c <b> 1 ′ to c <b> 3 ′ output from the gain adjustment unit 2 d of the adjustment value generation units 21 to 23 may be used. Further, instead of the total value calculation unit 34 in FIG. 6 or the minimum value selection unit 36 in FIG. 7, a combination of the total value calculation unit 34 and the minimum value selection unit 36 is used, and the total value and the minimum value are set at an appropriate ratio. You may mix.

  Furthermore, threshold values TH1 to TH3 and threshold value TH0 may be linked, attack times A1 to A3 and attack time A0 may be linked, and release times R1 to R3 and release time R0 are linked. May be.

  In the first to sixth embodiments, feed-forward multiband compression and single-band compression are performed. However, feedback multi-band compression and single-band compression may be performed. For example, the multipliers 51 to 53 of FIG. 1 are provided between the band pass filters 11 to 13 and the threshold value setting unit 2a. The multipliers 51 to 53 multiply the signal components S1 to S3 output from the bandpass filters 11 to 13 by the adjustment values C1 to C3 output from the ratio adjustment unit 2e, and the multiplication results are signal components S1 ′ to S3. It is given to the threshold value setting unit 2a and the synthesis unit 40 as'. Similarly, a multiplier 50 is provided between the combining unit 40 and the threshold setting unit 3a. The multiplier 50 multiplies the synthesized acoustic signal SF output from the synthesizing unit 40 and the adjustment value C0 output from the ratio adjusting unit 3e, and outputs the multiplication result as the output acoustic signal SO and the threshold setting unit 3a. To give.

(7) Correspondence between each constituent element of claims and each element of the embodiment Hereinafter, an example of correspondence between each constituent element of the claims and each element of the embodiment will be described. It is not limited to.

  In the first to fifth embodiments, the band dividing unit 10 is an example of a band dividing unit, the ratio setting unit 100 is an example of a setting unit, and the adjustment value generating units 21 to 23 generate a first adjustment value. It is an example of a means. In the first to third embodiments, the adjustment value generation unit 30 is an example of a second adjustment value generation unit. In the fourth embodiment, the adjustment value generation units 21 to 23 and the total value calculation unit 34. The ratio adjustment unit 35 is an example of the second adjustment value generation unit. In the fifth embodiment, the adjustment value generation units 21 to 23, the minimum value selection unit 36, and the ratio adjustment unit 35 are the second adjustment values. It is an example of a production | generation means. In the first embodiment, the synthesizer 40 and the multipliers 50 to 53 are examples of acoustic signal generation means. In the second embodiment, the synthesizer 40 and the multipliers 51 to 53, 50a generate acoustic signals. In the third to fifth embodiments, the synthesis unit 40, the multipliers 51 to 35, and the adders 61 to 63 are examples of acoustic signal generation means.

  Furthermore, in the fifth embodiment, the minimum value selection unit 36 is an example of a selection unit, and in the fourth embodiment, the total value calculation unit 34 is an example of a calculation unit. Further, the ratios Ra1 ′ to Ra3 ′ are examples of the first parameter, the ratio Ra0 ′ is an example of the second parameter, and the adjustment values C1 to C3 and C1 ′ to C3 ′ are examples of the first adjustment value. The adjustment values C0, CS, CS′CSa, CSb are examples of the second adjustment value, the compression coefficients c1 to c3, c1 ′ to c3 ′ are examples of the first compression coefficient, and the compression coefficient c0 , C0 ′ is an example of the second compression coefficient.

  As each constituent element in the claims, various other elements having configurations or functions described in the claims can be used.

  The present invention can be used for adjusting the level of an acoustic signal.

  DESCRIPTION OF SYMBOLS 1 ... Acoustic signal processing apparatus, 10 ... Band division part, 21-23, 30 ... Adjustment value production | generation part, 34 ... Total value calculation part, 36 ... Minimum value selection part, 40 ... Synthesis | combination part, 50-53, 50a ... Multiplication 61-63 ... adder, 100 ... ratio setting unit, 110 ... operation unit

Claims (6)

An acoustic signal processing device that generates an output acoustic signal by adjusting a level of an input acoustic signal,
Band dividing means for dividing the input acoustic signal into signal components of a plurality of bands;
Setting means for setting a plurality of first parameters corresponding to the plurality of bands and a second parameter corresponding to a single band including the plurality of bands;
A plurality of first adjustment value generating means for respectively generating a plurality of first adjustment values based on the levels of the signal components of the plurality of bands and the plurality of first parameters;
Second adjustment value generation means for generating a second adjustment value based on the level of the signal component of the single band and the second parameter;
Level adjusting means for adjusting the level of the signal components of the plurality of bands based on the plurality of first adjustment values, and adjusting the level of the signal component of the single band based on the second adjustment values; ,
Acoustic signal generating means for generating the output acoustic signal based on the signal component adjusted by the level adjusting means,
The setting means is an acoustic signal processing device which links each first parameter and the second parameter so that the other changes complementarily by adjusting one of the first parameter and the second parameter. . The plurality of first adjustment value generation units respectively generate a plurality of first adjustment coefficients based on levels of signal components in the plurality of bands, and generate the plurality of first adjustment coefficients and the plurality of first adjustment coefficients. Generating the plurality of first adjustment values based on one parameter;
The second adjustment value generation means is configured to output the second adjustment value based on a total value or minimum value of a plurality of first adjustment coefficients generated by the plurality of first adjustment value generation means and the second parameter. Generate an adjustment value for
The level adjusting means adjusts the level of each signal component of the plurality of bands based on a plurality of addition values obtained by adding the second adjustment value to each of the plurality of first adjustment values,
The acoustic signal processing apparatus according to claim 1, wherein the acoustic signal generation unit generates the output acoustic signal by combining the signal components of the plurality of bands adjusted by the level adjustment unit. The second adjustment value generation means generates a second adjustment coefficient based on the level of the signal component of the single band, and the second adjustment value generation means generates the second adjustment coefficient based on the generated second adjustment coefficient and the second parameter. The acoustic signal processing device according to claim 1, wherein the adjustment value of 2 is generated. The second adjustment value generating means generates the second adjustment coefficient based on the level of the input acoustic signal,
The level adjustment means adjusts the level of each signal component of the plurality of bands based on an addition value obtained by adding the second adjustment value to each of the plurality of first adjustment values,
The acoustic signal processing apparatus according to claim 3, wherein the acoustic signal generation unit generates the output acoustic signal by combining signal components of a plurality of bands adjusted by the level adjustment unit. The level adjustment means includes a plurality of first multipliers that adjust levels of signal components in the plurality of bands based on the plurality of first adjustment values, and the single adjustment unit based on the second adjustment values. and a second multiplier for adjusting the level of the signal component of the band, the sound signal processing apparatus according to claim 1 or 3 wherein. The level adjusting unit is configured to adjust a level of each signal component of the plurality of bands based on a plurality of addition values obtained by adding the second adjustment value to each of the plurality of first adjustment values. The acoustic signal processing apparatus according to any one of claims 1 to 4, comprising a container.

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