JP2013201564A - Acoustic processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust localization direction of respective frequency components of an acoustic signal precisely with ease.SOLUTION: An acoustic processing device 100 generates a 5-channel acoustic signal Y from a 2-channel acoustic signal X. A display control part 36 causes a display device 26 to display a sound image distribution picture 50 representing sound image distribution of respective frequency components within a sound image plane in which a radial direction whose center is a reference point P0 corresponds to a frequency while a circumferential direction corresponds to a localization direction. The display control part 36 shifts the sound image distribution in an operational target region B corresponding to a frequency range AF set in radial direction in the sound image plane and a localization range AP set in the circumferential direction, to the circumferential direction according to instruction from a user. An acoustic signal Y is generated from an acoustic signal X in such a manner as the sound image distribution of respective frequency components of the acoustic signal Y corresponds to the sound image distribution which is represented by the sound image distribution picture 50 after the operational target region B is shifted.

Description

  The present invention relates to a technique for controlling a sound field formed by acoustic signals of a plurality of channels.

  Various techniques have been proposed in the past for variably controlling a sound field formed by reproducing sound signals of a plurality of channels in accordance with instructions from a user. For example, in Non-Patent Document 1, as shown in FIG. 8, a sound field formed by a plurality of sound emitting devices 94 is represented by a circular region 92 centered on a reference point 90 corresponding to the position of the listener of the reproduced sound. A technique for displaying on a display device as a GUI (Graphical User Interface) is disclosed. The user can arbitrarily specify the localization direction 96 of the reproduced sound by operating the circular area 92.

Waves Audio Ltd., S360 ° Surround Panner, [online], [Search January 23, 2012], Internet <URL: http://www.waves.com/Content.aspx?id=229>

  However, in the technique of Non-Patent Document 1 in which the user specifies the localization position of the entire reproduced sound, the localization direction of the component within a specific band of the acoustic signal is selectively controlled, or the specific position of the acoustic signal is specified. It is not assumed that the localization direction of the component localized in the direction is selectively controlled. Therefore, for example, about the sound (for example, the performance sound of a specific musical instrument) from a sound source in a desired range located in a desired direction among the mixed sound of sounds generated in parallel by a plurality of sound sources installed at different positions. It is not possible to make precise adjustments such as selectively changing the orientation direction. In view of the above circumstances, an object of the present invention is to precisely and easily adjust the localization direction of each frequency component of an acoustic signal.

  Means employed by the present invention to solve the above problems will be described. In order to facilitate the understanding of the present invention, in the following description, the correspondence between the elements of the present invention and the elements of the embodiments described later will be indicated in parentheses, but the scope of the present invention will be exemplified in the embodiments. It is not intended to be limited.

  The acoustic processing device of the present invention is a device that generates a plurality of channels of second acoustic signals (for example, acoustic signal Y) from a first acoustic signal (for example, acoustic signal X), and a radial direction centered on a reference point is a frequency. And a sound image distribution image (for example, a sound image distribution image 50) representing the sound image distribution of each frequency component of the first acoustic signal in the sound image plane whose circumferential direction corresponds to the localization direction. An operation target area (for example, operation target area B) corresponding to a frequency range (for example, frequency range AF) set in the radial direction and a localization range (for example, localization range AP) set in the circumferential direction in the sound image plane. ) In the circumferential direction in accordance with an instruction from the user, and the sound image distribution of each frequency component of the second acoustic signal is moved in the operation target area. Of such sound image distribution image corresponding to the sound distribution of representing comprises a signal processing means for generating a second audio signal from the first acoustic signal (e.g. the signal processor 42).

  In the above configuration, since the sound image distribution in the operation target region corresponding to the specific frequency range and the specific localization range in the sound image plane moves according to the instruction from the user, it is compared with the technique of Non-Patent Document 1. Thus, the localization direction of each frequency component can be precisely adjusted. Also, since the sound image distribution in the operation target area moves in the circumferential direction around the reference point, the user can determine the localization direction of each frequency component while visually and intuitively checking the sound image distribution in the sound image plane. There is also an advantage that it can be easily adjusted. The “movement” of the operation target area (sound image distribution) implies both “move” in a narrow sense that does not maintain the operation target area before the operation and “duplication” that maintains the operation target area before the operation.

  In a preferred aspect of the present invention, the display control means uses an operation target area defined inside an initial distribution area (for example, the initial distribution area A0) in which each frequency component of the first acoustic signal is distributed in the sound image plane. In response to an instruction from the person, it moves outside the initial distribution area. In the above aspect, since the sound image distribution in the operation target area moves from the inside to the outside of the initial distribution area, it is possible to extend the range in which the sound image of the reproduced sound is distributed.

  In a preferred aspect of the present invention, the display control means variably sets the frequency range and the localization range in accordance with an instruction from the user. In the above aspect, since the frequency range and the localization range that define the operation target region are variably set in accordance with an instruction from the user, the frequency components (in a desired band localized in the user's desired direction) ( For example, various and precise adjustments such as selectively changing the localization direction of the performance sound of a musical instrument arranged in a specific direction are realized.

  In a preferred aspect of the present invention, the display control means arranges the intensity value (for example, the intensity value E) of each frequency component in the operation target area at a position corresponding to the operation target area, and in response to an instruction from the user. The signal processing unit adjusts the intensity of each frequency component in the operation target area according to the intensity value corresponding to the operation target area. In the above aspect, the intensity value corresponding to the operation target region is changed according to an instruction from the user, and is applied to the adjustment of the first acoustic signal by the signal processing means. Therefore, there is an advantage that the user can visually and intuitively adjust the intensity of each frequency component within the desired frequency range and the desired localization range. In the case where the operation target area is duplicated at another position, a configuration in which intensity values are arranged for both the operation target area before duplication and the operation target area after duplication is preferable.

  In a preferred aspect of the present invention, the display control means uses a sound emission point image (for example, the sound emission point image 60) representing the sound emission device of each channel of the second acoustic signal in the circumferential direction around the reference point. And the position of the sound emitting point image in the circumferential direction is variably set according to an instruction from the user, and the signal processing means is configured to output the sound emitting sound arranged at each position of the sound emitting point image. The second sound signal is generated from the first sound signal so that the sound image distribution of each frequency component when the apparatus reproduces the second sound signal corresponds to the sound image distribution represented by the sound image distribution image. In the above aspect, the position of the sound emission point image is variably set according to an instruction from the user and reflected in the sound image distribution of the reproduced sound. Therefore, by adjusting the position of the sound emission point image so as to correspond to the actual arrangement of the sound emission device, it is possible to faithfully reproduce the sound image distribution represented by the sound image distribution image in the actual acoustic space. is there.

  The sound processing apparatus according to each of the above aspects is realized by hardware (electronic circuit) such as a DSP (Digital Signal Processor) dedicated to processing of an acoustic signal, or a general-purpose operation such as a CPU (Central Processing Unit). This is also realized by cooperation between the processing device and the program. In order to generate a second acoustic signal of a plurality of channels from the first acoustic signal, the program of the present invention is in the sound image plane in which the radial direction around the reference point corresponds to the frequency and the circumferential direction corresponds to the localization direction. Display the sound image distribution image representing the sound image distribution of each frequency component of the first acoustic signal in the display device, the frequency range set in the radial direction and the circumferential direction set in the sound image plane Display control processing for moving the sound image distribution in the operation target area corresponding to the localization range in the circumferential direction according to an instruction from the user, and the sound image distribution of each frequency component of the second acoustic signal are A computer is caused to execute signal processing for generating a second acoustic signal from the first acoustic signal so as to correspond to the sound image distribution represented by the moved sound image distribution image. According to the above program, the same operation and effect as the sound processing apparatus of the present invention are exhibited. The program of the present invention is provided in a form stored in a computer-readable recording medium and installed in the computer, or is provided in a form distributed via a communication network and installed in the computer.

1 is a block diagram of a sound processing apparatus according to a first embodiment of the present invention. It is a schematic diagram of a localization setting image. It is a schematic diagram of the localization setting image after the movement of the operation target area. It is a schematic diagram of the localization setting image in 2nd Embodiment. It is a schematic diagram of the localization setting image in 3rd Embodiment. It is a schematic diagram of the localization setting image in a modification. It is a schematic diagram of the localization setting image in a modification. 10 is a schematic diagram of a display screen of Non-Patent Document 1. FIG.

<First Embodiment>
FIG. 1 is a block diagram of a sound processing apparatus 100 according to the first embodiment of the present invention. As shown in FIG. 1, a signal supply device 12 and five sound emitting devices 14 (14C, 14L, 14R, 14LS, and 14RS) are connected to the sound processing device 100. The signal supply device 12 supplies an acoustic signal X indicating a waveform of a mixed sound of a plurality of sounds (singing sound and instrument sound) generated by a plurality of sound sources to the sound processing device 100. The sound signal X is collected and processed (for example, processing for changing the intensity ratio and the delay amount between the left and right channels) so that the sound images corresponding to the sound sources are localized at different positions, and the sound signal XL and the right It is a stereo signal composed of the channel acoustic signal XR. A sound collection device that collects ambient sound to generate an acoustic signal X (XL, XR), a playback device that acquires the acoustic signal X from a portable or built-in recording medium, and an acoustic signal X from a communication network A receiving communication device may be employed as the signal supply device 12. Note that the acoustic processing device 100 and the signal supply device 12 can be configured integrally.

  Each sound emitting device 14 is arranged at a position surrounding the listener H. The sound emitting device 14C is arranged in front of the listener H, the sound emitting device 14L is arranged in front of the listener H, the sound emitting device 14R is arranged in front of the listener H, and the sound emitting device 14LS is received. The sound emitting device 14RS is disposed on the right rear side of the listener H. That is, the first embodiment is a 5-channel surround system using the sound processing apparatus 100. Note that a 5.1 channel surround system can be configured by adding a low-frequency sound emitting device (woofer).

  The sound processing apparatus 100 is a signal processing apparatus that generates a surround-type 5-channel sound signal Y (YC, YL, YR, YLS, YRS) from left and right 2-channel sound signals X. Each sound emitting device 14 reproduces a sound wave corresponding to the acoustic signal Y generated by the acoustic processing device 100. Specifically, the sound emitting device 14C reproduces the acoustic signal YC, the sound emitting device 14L reproduces the acoustic signal YL, the sound emitting device 14R reproduces the acoustic signal YR, and the sound emitting device 14LS reproduces the acoustic signal YLS. The sound emitting device 14RS reproduces the acoustic signal YRS. The acoustic signal XL is generated assuming reproduction from the sound emitting device 14L, and the acoustic signal XR is generated assuming reproduction from the sound emitting device 14R.

  As shown in FIG. 1, the sound processing device 100 is realized by a computer system including an arithmetic processing device 22, a storage device 24, a display device 26, and an input device 28. The display device 26 (for example, a liquid crystal display panel) displays various images according to instructions from the arithmetic processing device 22. The input device 28 is a device that receives an instruction from the user to the sound processing device 100, and includes, for example, a plurality of operators operated by the user. Note that a touch panel configured integrally with the display device 26 can be used as the input device 28.

  The storage device 24 stores programs executed by the arithmetic processing device 22 and various types of information used by the arithmetic processing device 22. A known recording medium such as a semiconductor recording medium or a magnetic recording medium or a combination of a plurality of types of recording media is arbitrarily adopted as the storage device 24. A configuration in which each acoustic signal X is stored in the storage device 24 (therefore, the signal supply device 12 is omitted) may be employed.

  The arithmetic processing unit 22 executes a program stored in the storage device 24, thereby performing a 5-channel acoustic signal Y (YC, YL, YR, YLS, YRS) from the left-right 2-channel acoustic signal X (XL, XR). A plurality of functions (frequency analysis unit 32, localization analysis unit 34, display control unit 36, signal processing unit 42, waveform synthesis unit 44) are generated. A configuration in which each function of the arithmetic processing device 22 is distributed to a plurality of devices, or a configuration in which a dedicated electronic circuit (DSP) realizes a part of the functions of the arithmetic processing device 22 may be employed.

  The frequency analysis unit 32 sequentially calculates a plurality of frequency components (frequency spectra) corresponding to different frequencies F [k] for each of the acoustic signal XL and the acoustic signal XR for each unit period on the time axis. The symbol k is a variable indicating one arbitrary frequency among a plurality of frequencies (frequency bands) set on the frequency axis. For calculation of each frequency component of the acoustic signal XL and the acoustic signal XR, a known frequency analysis such as short-time Fourier transform is arbitrarily employed. A filter bank composed of a plurality of bandpass filters having different passbands may be employed as the frequency analysis unit 32.

The localization analysis unit 34 calculates the localization direction θ [k] of each frequency component of the acoustic signal X. A known technique can be arbitrarily employed for calculating the localization direction θ [k]. For example, the intensity | XL [k] | of each frequency component of the acoustic signal XL and the intensity | XR of each frequency component of the acoustic signal XR The calculation of the following formula (1) to which [k] | is applied is preferable. In the localization direction θ [k] calculated by Expression (1), the numerical value 0 means the front direction of the listener H, and the left side with respect to the front direction is expressed as a negative number and the right side is expressed as a positive number. The formula (1) is also described in detail in, for example, M. Vinyes, J. Bonada, A. Loscos, “Demixing Commercial Music Productions via Human-Assisted Time-Frequency Masking”, Audio Engineering Society 120th Convention, France, 2006. It is stated.

  The display control unit 36 in FIG. 1 causes the display device 26 to display the localization setting image G in FIG. 2 expressing the analysis result by the localization analysis unit 34. As shown in FIG. 2, the localization setting image G includes a sound image distribution image 50 representing a distribution of sound images of each frequency component (hereinafter referred to as “sound image distribution”) and five sound emission devices 14 representing each channel. The sound emission point image 60 (60C, 60L, 60R, 60LS, 60RS) is included.

  The sound image distribution image 50 is a circular image representing a sound image distribution in a coordinate plane centered on the reference point P0 (hereinafter referred to as “sound image plane”). The reference point P0 corresponds to the position (listening point) of the listener H of the reproduced sound. In the sound image plane, the radial direction centered on the reference point P0 means the frequency, and the circumferential direction centered on the reference point P0 means the localization direction. That is, an arbitrary straight line extending in the radial direction from the reference point P0 corresponds to the frequency axis, and an arbitrary concentric circle centered on the reference point P0 corresponds to the coordinate axis in the localization direction. The radial straight line DC shown in FIG. 2 means the front direction of the listener H located at the reference point P0, and the opposite side of the front direction DC across the reference point P0 means the back direction of the listener H. . Therefore, a semicircular range extending 180 ° counterclockwise with respect to the front direction DC corresponds to the left side of the listener H (from the left front to the left rear), and half a range extending 180 ° clockwise with respect to the front direction DC. A circular range corresponds to the right side (right front to right rear) of the listener H.

  Each sound emitting point image 60 is arranged at a position corresponding to each sound emitting device 14 (on the circumference centering on the reference point P0) in the region around the sound image distribution image 50. Specifically, the sound emitting point image 60C representing the sound emitting device 14C is arranged in the front direction DC, and the sound emitting point image 60L representing the sound emitting device 14L is located on the left front of the reference point P0 (for example, in the front direction DC). On the other hand, the sound emission point image 60R, which is arranged in the counterclockwise direction 30 °) DL and represents the sound emission device 14R, is the right front of the reference point P0 (for example, the direction 30 ° clockwise relative to the front direction DC). ) It is arranged in DR. The sound emission point image 60LS representing the sound emission device 14LS is arranged at the left rear DLS of the reference point P0, and the sound emission point image 60RS representing the sound emission device 14RS is arranged at the right rear DRS of the reference point P0. .

  The display control unit 36 arranges a plurality of sound image figures Q representing each frequency component in a specific section (hereinafter referred to as “display target section”) of the acoustic signal X on the sound image plane. The display target section is composed of one or more unit periods selected by, for example, the user operating the input device 28 in the acoustic signal X. The sound image figure Q corresponding to the frequency component of the frequency F [k] in the acoustic signal X in the display target section includes a point corresponding to the frequency F [k] among a plurality of points along the radial direction in the sound image plane, Of the plurality of points along the circumferential direction in the sound image plane, the localization analysis unit 34 is located at coordinates defined by the point corresponding to the localization direction θ [k] calculated for the frequency F [k]. That is, the frequency component of the frequency F [k] is applied to the intersection of the circular arc having the radius corresponding to the frequency F [k] with the reference point P0 as the center and the straight line extending from the reference point P0 in the localization direction θ [k]. A sound image figure Q to be represented is arranged. As understood from the above description, the sound image distribution of each frequency component of the acoustic signal X is expressed by each sound image figure Q in the sound image plane. That is, the user visually and intuitively confirms the relationship (sound image distribution) between the frequency F [k] of each frequency component of the acoustic signal X and the localization direction θ [k] by visually recognizing the sound image distribution image 50. Is possible. Note that the display mode of the sound image figure Q of each frequency component (for example, visually recognizable properties such as color, gradation, size, etc.) is determined according to the intensity of each frequency component (eg, intensity | XL [k] | and intensity | XR [ A configuration in which control is variably performed in accordance with one of k] | and the average of both is also preferable.

  The localization direction θ [k] of each frequency component is calculated by the calculation of Equation (1) using the left channel acoustic signal XL and the right channel acoustic signal XR. Accordingly, each localization direction θ [k] calculated by the localization analysis unit 34 is a sector area (hereinafter referred to as “initial distribution area”) A0 sandwiched between the left front DL and the right front DR in front of the reference point P0. Is contained within. That is, in the sound image distribution image 50 in an initial state in which the instruction from the user is not reflected in the sound image distribution, all sound image figures Q corresponding to each frequency component are distributed inside the initial distribution area A0.

  The display control unit 36 divides the initial distribution area A0 in the sound image plane into a plurality of operation target areas B in accordance with an instruction from the user to the input device 28. Each operation target area B is an arc-shaped (arch-shaped) area obtained by dividing the initial distribution area A0 in the radial direction and the circumferential direction. Specifically, the display control unit 36 divides the initial distribution region A0 into a plurality of ranges (hereinafter referred to as “frequency ranges”) AF in the radial direction with each arc-shaped dividing line SC centered on the reference point P0 as a boundary. Then, the initial distribution region A0 is divided into a plurality of ranges (hereinafter referred to as "localization ranges") AP in the circumferential direction, with each of the straight dividing lines SR extending in the radial direction from the reference point P0 as a boundary. The radial position (each frequency range A F) of each segment line SC and the circumferential position (localization range AP) of each segment line SR are variably set according to instructions from the user.

  Each operation target area B is an area surrounded by each division line SR and each division line SC. That is, the display control unit 36 sets the operation target area B corresponding to the frequency range A F defined by each segment line SC and the localization range AP defined by each segment line SR according to an instruction from the user. . The user includes the operation target region B (including a desired frequency) so as to include a desired frequency component (for example, a musical instrument sound in a desired sound range localized in a desired localization direction) of the acoustic signal X in the initial distribution region A0. A frequency range AF and a localization range AP including a desired localization direction are designated.

  The user can instruct the acoustic processing device 100 to move an arbitrary operation target region B in the sound image plane by appropriately operating the input device 28 (for example, dragging with the mouse). The display control unit 36 moves the sound image distribution (a set of a plurality of sound image figures Q) in the operation target area B instructed by the user in the circumferential direction in accordance with the instruction from the user. Specifically, as shown by the broken-line arrows in FIG. 3, the sound image distribution in each operation target area B in the initial distribution area A0 is arbitrarily moved along the circumferential direction to the area outside the initial distribution area A0. Move by the amount. That is, the localization direction θ [k] of each frequency component of the acoustic signal X is changed for each operation target region B in an arbitrary direction selected from all directions (360 °) around the reference point P0.

  The signal processing unit 42 in FIG. 1 generates each frequency component (frequency spectrum) of the acoustic signal Y (YC, YL, YR, YLS, YRS) for each channel by signal processing for each frequency component of the acoustic signal X. Specifically, the signal processing unit 42 represents the sound image distribution of each frequency component of the acoustic signal Y of each channel as a sound image distribution image 50 reflecting an instruction from the user (movement of the operation target region B). Each frequency component for each channel of the acoustic signal Y is generated from each frequency component of the acoustic signal X so as to correspond to the sound image distribution. For example, in the sound image distribution image 50 after movement of the operation target region B, the frequency component (sound image) of the frequency F [k] where the localization direction θ [k] is located between the left rear DLS and the right rear DRS of the reference point P0. For the frequency component in which the graphic Q is located behind the reference point P0, the frequency component of the frequency F [k] in the acoustic signal X is a phase difference and intensity ratio corresponding to the localization direction θ [k] after the change. It is distributed to the frequency components of the frequency F [k] in each of the acoustic signal YLS and the acoustic signal YRS. Similarly, the frequency component of the frequency F [k] in which the localization direction θ [k] after the change is located to the left of the reference point P0 (between the left front DL and the left rear DLS) The frequency component of the frequency F [k] is distributed to the frequency component of the frequency F [k] in each of the acoustic signal YL and the acoustic signal YLS with a phase difference and an intensity ratio according to the changed localization direction θ [k]. .

  The waveform synthesizer 44 generates acoustic signals Y (YC, YL, YR, YLS, YRS) of each channel from the frequency components generated for each channel by the signal processor 42. Specifically, the waveform synthesis unit 44 connects the time domain signals generated by the short-time inverse Fourier transform for each frequency component (frequency spectrum) of the acoustic signal YC to each other in the unit period before and after the acoustic signal YC. Is generated. The sound signal Y of each channel is supplied to each sound emitting device 14 and reproduced as a sound wave. Therefore, a sound field in which the sound image of each frequency component of the reproduced sound is localized at the localization position θ [k] specified in the sound image distribution image 50 after movement of each operation target region B is formed around the listener H. .

  In the first embodiment described above, the localization direction θ [k] (sound image distribution) of each frequency component in the operation target area B defined on the sound image plane by the frequency range AF and the localization range AP is determined from the user. Changed according to instructions. That is, the localization direction θ [k] is selectively changed only for a specific frequency component in the acoustic signal X. Therefore, compared with the technique of Non-Patent Document 1, it is possible to finely adjust the localization direction θ [k] of each frequency component. Further, since the sound image distribution in the operation target area B moves in the circumferential direction around the reference point P0 corresponding to the listener H, the user can grasp the sound image distribution in the sound image plane visually and intuitively. However, there is an advantage that the localization direction θ [k] of each frequency component can be easily adjusted.

  In the first embodiment, the frequency range A F and the localization range AP that define the operation target region B are variably set according to an instruction from the user. Therefore, the localization direction θ [k] is selectively changed only for sound from a sound source in a desired range localized in a desired direction (for example, a performance sound of an instrument arranged in a specific direction during recording). Adjustment is possible.

Second Embodiment
A second embodiment of the present invention will be described below. In addition, about the element which an effect | action and function are the same as that of 1st Embodiment in each form illustrated below, the reference | standard referred by description of 1st Embodiment is diverted and each detailed description is abbreviate | omitted suitably.

  FIG. 4 is a schematic diagram of a localization setting image G in the second embodiment. As shown in FIG. 4, the sound image distribution image 50 displayed on the display device 26 by the display control unit 36 of the second embodiment adds the intensity value E of each operation target region B to the sound image distribution image 50 of the first embodiment. It is an image. Each intensity value E is a numerical value of the average intensity (volume) of each frequency component in the operation target area B, and is arranged in or near the operation target area B.

  The user appropriately operates the input device 28 (for example, by operating an operator such as a slider displayed when the desired operation target area B is selected by the input device 28 such as a mouse or a touch panel). It is possible to instruct to change the intensity value E of the operation target area B. The display control unit 36 changes the intensity value E of each operation target region B in accordance with an instruction from the user to the input device 28. Each intensity value E is arranged in or near the operation target area B even after the operation target area B is moved according to an instruction from the user. The signal processing unit 42 controls the intensity (amplitude) of each frequency component in the operation target area B in the acoustic signal Y according to the intensity value E specified for the operation target area B.

  In the second embodiment, the same effect as in the first embodiment is realized. Further, the second embodiment has an advantage that the user can easily adjust the intensity value E of each frequency component while visually and intuitively grasping the sound image distribution in the sound image plane together with the intensity value E.

<Third Embodiment>
FIG. 5 is a schematic diagram of a localization setting image G in the third embodiment. As illustrated by arrows in FIG. 5, the display control unit 36 of the third embodiment variably controls the position of each sound emission point image 60 with respect to the sound image distribution image 50. The user can instruct to move the desired sound emitting point image 60 by appropriately operating the input device 28. The display control unit 36 moves each sound emission point image 60 in the circumferential direction around the reference point P 0 in accordance with an instruction from the user to the input device 28.

  In the signal processing unit 42, the sound image distribution of each frequency component when the sound emitting device 14 arranged at each position of the sound emitting point image 60 reproduces the acoustic signal Y of each channel is represented by the sound image distribution image 50. Each frequency component of the acoustic signal Y of each channel is generated from each frequency component of the acoustic signal X so as to correspond to the sound image distribution. Specifically, the frequency component of each frequency F [k] of the acoustic signal X with a phase difference and an intensity ratio according to the positional relationship between each position of the sound emission point image 60 and the localization direction θ [k] of each frequency component. Are distributed to the acoustic signal Y of each channel.

  In the third embodiment, the same effect as in the first embodiment is realized. In the third embodiment, since the position of each sound emitting point image 60 adjusted according to the instruction from the user is reflected in the generation of the acoustic signal Y, the actual arrangement position of each sound emitting device 14 is reflected. By adjusting the sound emission point image 60 accordingly, the sound image distribution expressed by the sound image distribution image 50 can be faithfully reproduced in the actual acoustic space.

  In the above description, the case where the user individually changes the position of each sound emission point image 60 is exemplified. However, a plurality of pieces of position information (templates) for specifying different positions for each sound emission point image 60 are provided. A configuration stored in advance in the storage device 24 may also be employed. The position of each sound emission point image 60 is set according to the position information selected by the user from among the plurality of position information.

<Modification>
Various modifications can be made to each of the forms exemplified above. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined.

(1) In each of the above-described embodiments, the case where the operation target region B is moved in the circumferential direction is illustrated, but the display control unit 36 moves the operation target region B in the radial direction (frequency axis direction) in response to an instruction from the user. ) Is also possible. Movement in the radial direction of the operation target region B (sound image distribution of each frequency component) means a change in pitch (pitch shift) of the frequency component. Therefore, the signal processing unit 42 generates the acoustic signal Y of each channel by adjusting the pitch of each frequency component in each operation target region B according to the amount of movement of the operation target region B in the radial direction.

  In addition, as shown in FIG. 6, the operation target area B can be expanded and contracted in the circumferential direction in accordance with an instruction from the user. FIG. 6 illustrates a case where one operation target region B in the localization setting image G illustrated in FIG. 2 is extended in the circumferential direction. The display control unit 36 expands and contracts the sound image distribution in the operation target region B in conjunction with the expansion and contraction of the operation target region B. That is, when the operation target area B is expanded in the circumferential direction, the circumferential interval between the sound image figures Q in the operation target area B is expanded according to the expansion rate, and the operation target area B is expanded in the circumferential direction. When the sound image figure Q is shrunk, the interval between the sound image figures Q in the operation target area B in the circumferential direction is reduced according to the reduction ratio. Before and after expansion / contraction of the operation target area B, each operation target area B is moved in the circumferential direction (or radial direction) according to an instruction from the user. For example, the operation target region B is contracted to a substantially linear shape (a shape in which each sound image figure Q is linearly arranged) and appropriately moved in the circumferential direction, so that each frequency component in the operation target region B is It is possible to control the sound image distribution so that the reproduced sound is emitted from only one specific sound emitting device 14.

(2) Although all frequency components are reproduced from each sound emitting device 14 in each of the above-described embodiments, one or more operation target regions B selected from the sound image distribution image 50 (for example, the operation target region B selected by the user). It is also possible to selectively reproduce only the frequency components in () from each sound emitting device 14.

(3) In each of the above-described embodiments, the 5-channel acoustic signal Y (YC, YL, YR, YLS, YRS) corresponding to each sound emitting device 14 is generated from the 2-channel acoustic signal X (XL, XR). The number of channels of the acoustic signal X and the acoustic signal Y is changed as appropriate. For example, in the configuration in which the acoustic signal X of 3 channels or more (for example, 5 channels) is supplied to the acoustic processing device 100, the localization direction θ [k] of each frequency component is calculated from the acoustic signal X of each channel. Therefore, the initial distribution area A0 is an area extending around the entire circumference with the reference point P0 as the center. In addition, a configuration in which the number of channels to be processed by the sound processing apparatus 100 among the sound signals X of three or more channels is variably set according to an instruction from a user, for example, is also suitable.

  Also, by convolving the head-related transfer function with the 5-channel acoustic signal Y generated in the same manner as in the above-described embodiments, a 2-channel acoustic signal that virtually forms a sound field similar to those in the above-described embodiments is obtained. It is also possible to generate. Further, in each of the above-described embodiments, the localization direction of each frequency component is controlled for all the channels of the acoustic signal Y, but it is also possible to exclude a specific channel from the localization direction adjustment target. For example, in the case of a video work such as a movie, the front acoustic signal YC often includes voices such as characters of the characters, and the recorded sound of the song includes the front acoustic signal YC including the singing sound (main vocal). There is a tendency that there are many. Under the above tendency, a configuration in which the acoustic signal YC is excluded from the adjustment target by the signal processing unit 42 and is localized in the intended direction is preferable.

  It is also possible to supply a monaural (one channel) acoustic signal X to the acoustic processing apparatus 100. When the monaural sound signal X is supplied to the sound processing apparatus 100, the sound signal X can be distributed to two channels and the localization direction θ [k] of each frequency component can be calculated. In the above configuration, in the initial state of the localization setting image G, a plurality of sound image figures Q corresponding to each frequency component are arranged linearly along the front direction DC. It is also possible to process the monaural sound signal X after converting it to a stereo sound signal X (XL, XR). For example, a stereo acoustic signal X is generated by applying an acoustic effect such as stereo reverb to the acoustic signal X (and adjusting the balance of each channel).

(4) In each of the above-described embodiments, the case where each sound emitting device 14 emits sound to the inner listener H is exemplified, but each sound emitting device 14 is arranged such that the sound emitting surface faces outward. The present invention can also be applied when a sound field is formed around the sound emitting device 14. In the localization setting image G when the sound emitting devices 14 are arranged outward, sound emitting point images 60 representing the sound emitting devices 14 facing outward with respect to the reference point P0 are arranged. Each sound image figure Q is arranged on the sound image plane around the.

(5) In each embodiment described above, the initial distribution area A0 is divided into a plurality of operation target areas B in the radial direction and the circumferential direction. However, the selection method of each operation target area B and the shape of each operation target area B are as described above. It is not limited to the illustration. For example, a configuration in which an operation target region B having an arbitrary shape is set in accordance with an instruction from the user to the input device 28, or a configuration in which a plurality of operation target regions B overlap each other in the radial direction or the frequency direction may be employed. .

(6) As illustrated in FIG. 7, the sound image distribution in each operation target region B can be copied (copied) to the position while the sound image distribution in each operation target region B is maintained. The intensity value E exemplified in the second embodiment is arranged in both the duplication source operation target area B and the duplication destination operation target area B. The signal processing unit 42 generates the acoustic signal Y so as to correspond to the reproduced sound image distribution of each operation target region B. However, simply duplicating the frequency component in each operation target area B may increase the volume of the acoustic signal Y compared to the acoustic signal X, resulting in an unnatural impression. Therefore, in order that the volume of the acoustic signal Y does not increase excessively even when the operation target area B is duplicated, the intensity of each frequency component of the operation target area B that is the duplication source and each frequency component of the operation target area B that is the duplication destination It is also possible to adjust (reduce) the strength of the material. For example, the signal processing unit 42 multiplies the intensity of each frequency component in the duplication source operation target area B by a predetermined adjustment value (gain) of about 0.9, for example, in the duplication destination operation target area B. Is multiplied by an adjustment value (for example, about 0.4) lower than the adjustment value of the copy source. As can be understood from the above description, the “movement” of the sound image distribution in the present invention includes both “moving” in a narrow sense that does not maintain the sound image distribution before the operation and “duplication” that maintains the sound image distribution before the operation. It is a concept that includes Note that the duplication of the operation target region B (sound image distribution) can be repeated a plurality of times.

  When the sound image distribution in the operation target area B is duplicated at another position, the signal processing unit 42 can also apply various acoustic effects to each frequency component in the operation target area B that is the duplication destination. is there. For example, according to the configuration in which the signal processing unit 42 applies sound effects such as a delay or reverb of about 0.1 second to each frequency component in the operation target area at the duplication destination, the sound field can be easily operated by the user. It is possible to increase the feeling of spreading. In addition, a configuration in which the signal processing unit 42 extracts a reverberation component from each frequency component in the operation target area B that is the copy destination is also suitable. For example, the operation target area B located in front of the reference point P0 is duplicated behind the reference point P0, and the reverberation component is extracted from each frequency component in the duplication destination operation target area B. If reproduced together with each frequency component in B, it is possible to make the listener H perceive a sense of sound field expansion similar to an acoustic space such as an acoustic hall. It should be noted that any known technique (reverberation extraction technique, dereverberation suppression technique) can be arbitrarily employed for the process of extracting the reverberation component from each frequency component. When the reverberation suppression technique is used, for example, a direct sound component is estimated by reverberation suppression for each frequency component in the duplication source operation target area B, and a direct sound component is obtained from each frequency component in the duplication source operation target area B By subtracting, the reverberation component in the operation target area B can be estimated. It should be noted that the presence or absence of reverberation suppression for each frequency component in the operation target area B that is the copy source is not questioned.

(7) In the above-described embodiments, the sound image distribution in each operation target area B is moved while maintaining the sound image distribution. However, the sound image distribution before and after the movement (duplication) of the operation target area B needs to be strictly matched. Absent. For example, when the operation target area B is moved to the opposite side with respect to the reference point P 0, the sound image distribution in the operation target area B after the movement is changed, and the sound image distribution in the operation target area B before the movement is set in the circumferential direction. It is possible to set an inverted distribution. According to the above configuration, it is possible to increase the sense of expansion of the sound field with a simple operation by the user.

(8) The outer shape of the sound image distribution image 50 is not limited to a circle. For example, even when a fan-shaped (semicircle, 3/4 circle, etc.) or elliptical sound image distribution image 50 is displayed, the above-described embodiments can be similarly adopted. Further, the outer shape of the sound image distribution image 50 can be a polygonal shape (for example, a square or a triangle). For example, a configuration that displays a rectangular sound image distribution image 50 that represents an acoustic space in which each sound emitting device 14 is actually installed is suitable. As understood from the above description, the sound image distribution image 50 is included as an image representing the sound image distribution of each frequency component in the sound image plane, and the external shape of the sound image distribution image is arbitrary. As can be understood from the examples of the above-described embodiments, the sound image plane typically has a radial direction (a direction of a straight line extending radially from the reference point P0) corresponding to a frequency, and a circumferential direction ( The arc around the reference point P0 (the direction of the elliptical arc is also included) is a plane corresponding to the localization direction.

(9) In each of the above embodiments, the sound image distribution image 50 is displayed as a planar image. However, the sound image distribution image 50 is a three-dimensional shape such as a spherical shape or a cubic shape (for example, the internal shape of the acoustic space in which each sound emitting device 14 is installed). It is also possible to display on the display device 26 as an image. A plane that crosses the solid representing the sound image distribution image 50 and passes through the reference point P0 corresponds to the sound image plane. In the configuration in which the sound image distribution image 50 is displayed as a stereoscopic image, it is possible to adjust the vertical sound image localization relative to the reference point P0 in addition to the horizontal sound image localization relative to the reference point P0. Therefore, it is particularly suitable for a configuration in which the sound image is localized in the vertical direction of the listener H as in the 9.1 channel surround system.

(10) The selection method of the position which arrange | positions each sound emission point image 60 is arbitrary. For example, a configuration in which the position of each sound emission point image 60 is automatically selected according to the number of channels of the acoustic signal Y (number of sound emission point images 60) is suitable. For example, the user has selected a configuration in which the sound emission point images 60 are arranged at positions corresponding to the standard of ITU-R BS.775-1 or a plurality of templates that define the positions of the sound emission point images 60. A configuration in which the sound emission point image 60 is arranged at each position defined by the template is suitable.

(11) In the second embodiment, the intensity value E of each frequency component in the operation target region B is displayed. However, a configuration for adjusting each frequency component in the operation target region B (for example, imparting an acoustic effect to each frequency component) In this configuration, instead of the intensity value E (or together with the intensity value E), it is also possible to display parameters for adjusting each frequency component corresponding to the operation target region B.

(12) In each of the above-described embodiments, the acoustic processing device 100 that processes the acoustic signal X in accordance with an instruction from the user with respect to the localization setting image G is exemplified. However, the result (localization) of the sound image distribution of the acoustic signal X is analyzed. The present invention can also be realized as an acoustic analysis device that displays the setting image G). The acoustic analysis device displays the localization analysis unit 34 that calculates the localization direction θ [k] of each frequency component of the acoustic signal X, and the display control that displays the localization setting image G that represents the sound image distribution of each frequency component on the display device 26. Part 36. As can be understood from the above description, the signal processing unit 42 exemplified in each of the above embodiments can be omitted.

DESCRIPTION OF SYMBOLS 100 ... Sound processing device, 12 ... Signal supply device, 14 ... Sound emission device, 22 ... Arithmetic processing device, 24 ... Storage device, 26 ... Display device, 28 ... Input device, 32 ... Frequency Analysis unit 34... Localization analysis unit 36... Display control unit 42... Signal processing unit 44... Waveform synthesis unit G G. Localization setting image 50 50 Sound image distribution image 60 (60C, 60L) , 60R, 60LS, 60RS) …… Sound emission point image, B …… Operation target area.

Claims (5)

An apparatus for generating a second acoustic signal of a plurality of channels from a first acoustic signal,
A sound image distribution image representing a sound image distribution of each frequency component of the first acoustic signal in a sound image plane in which the radial direction centered on the reference point corresponds to the frequency and the circumferential direction corresponds to the localization direction is displayed on the display device. A means for displaying a sound image distribution in an operation target region corresponding to a frequency range set in the radial direction and a localization range set in the circumferential direction in the sound image plane, based on an instruction from a user; Display control means for moving in the circumferential direction accordingly,
The second sound signal is generated from the first sound signal so that the sound image distribution of each frequency component of the second sound signal corresponds to the sound image distribution represented by the sound image distribution image after movement of the operation target region. A sound processing apparatus comprising: signal processing means. The display control means sets the operation target area defined inside an initial distribution area in which each frequency component of the first acoustic signal is distributed in the sound image plane according to an instruction from a user. The sound processing apparatus according to claim 1. The sound processing apparatus according to claim 1, wherein the display control unit variably sets the frequency range and the localization range according to an instruction from a user. The display control means arranges the intensity value of each frequency component in the operation target area at a position corresponding to the operation target area and changes it according to an instruction from the user,
The acoustic processing apparatus according to claim 1, wherein the signal processing unit adjusts the intensity of each frequency component in the operation target area according to an intensity value corresponding to the operation target area. The display control means arranges sound emitting point images representing sound emitting devices of the respective channels of the second acoustic signal at respective positions in the circumferential direction around the reference point, and also releases the sound emitting points in the circumferential direction. The position of the sound spot image is variably set according to the instruction from the user,
The signal processing means converts the sound image distribution of each frequency component when a sound emitting device arranged at each position of the sound emitting point image reproduces the second acoustic signal into a sound image distribution represented by the sound image distribution image. The acoustic processing device according to claim 1, wherein the second acoustic signal is generated from the first acoustic signal so as to correspond.

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