Audio signal processing method and audio signal processing apparatus

Abstract

To provide a sound signal processing method and a sound signal processing device that improve the quality of early reflected sound.SOLUTION: A sound signal processing device 10 receives sound signals S1-S96 of a plurality of sound sources OBJ1-OBJ96. A grouping unit 40 groups the sound sources OBJ1-OBJ96 into a plurality of areas Area1 to Area8, and uses the sound signals S1-S96 of the sound sources OBJ1 to OBJ96 to generate area-specific sound signals SA1 to SA8 for each of the areas Area1 to Area8. An early reflected sound control signal generation unit 50 sets an imaginary sound source for each group using the positions of speakers SP1 to SP64 arranged in a reproduction space and the geometric shape of the virtual space, and generates early reflection control signals ER1 to ER64 that simulates the early reflected sound in the virtual space. At this time, the early reflected sound control signal generation unit performs desired tone color adjustment on the early reflected sound control signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One embodiment of the present invention relates to a sound signal processing method and a sound signal processing apparatus for performing predetermined processing on sound input from a sound source.

Background Art

[0002] In an acoustic system for a hall or the like, various techniques for controlling reflected sound have been put into practical use.

[0003] For example, the reflected sound generation device described in Patent Document 1 includes a first FIR filter and a second FIR filter. The first FIR filter performs a convolution operation on an audio signal with a first reflected sound parameter to generate first reflected sound data. The second FIR filter performs a convolution operation on the first reflected sound data with a second reflected sound parameter to generate second reflected sound data.

[0004] Thereby, the reflected sound generation device described in Patent Document 1 generates reflected sound composed of early reflected sound and late reverberation sound.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, with the above-described conventional configuration, it is difficult to improve the sound quality of early reflected sound.

[0007] Therefore, an object of one embodiment of the present invention is to improve the sound quality of early reflected sound.

Means for Solving the Problems

[0008] The audio signal processing method acquires an audio signal of a sound source, performs a first filter process on the audio signal to generate a virtual sound source in a virtual space, performs a second filter process on the audio signal to adjust the timbre of the virtual sound source, and outputs an initial reflected sound control signal generated by the audio signal subjected to the first filter process and the second filter process.

Effect of the Invention

[0009] The audio signal processing method can improve the sound quality of the initial reflected sound.

Brief Description of the Drawings

[0010]

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DETAILED DESCRIPTION OF THE INVENTION

[0011] A sound signal processing method and a sound signal processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, first, an overview of the sound signal processing method and the sound signal processing apparatus will be described, and then, specific details of each process and each configuration will be described.

[0012] In this embodiment, the playback space is a space where a user (listener) listens to sound (direct sound, early reflection sound, reverberation sound) from a sound source using a speaker or the like. The virtual space is a space having a sound field (acoustics) different from the playback space, and is a space where early reflection sound and reverberation sound due to this sound field are reproduced (simulated) in the playback space.

[0013] [Schematic Configuration of Sound Signal Processing Apparatus] FIG. 1 is a functional block diagram showing the configuration of an acoustic system including a sound signal processing apparatus according to an embodiment of the present invention.

[0014] As shown in FIG. 1, the audio signal processing apparatus 10 includes a region setting unit 30, a grouping unit 40, an early reflection sound control signal generation unit 50, a mixer 60, a reverberation sound control signal generation unit 70, an adder 80, and an output adjustment unit 90. The audio signal processing apparatus 10 is realized by, for example, an electronic circuit that realizes each of the region setting unit 30, the grouping unit 40, the early reflection sound control signal generation unit 50, the mixer 60, the reverberation sound control signal generation unit 70, the adder 80, and the output adjustment unit 90, or an arithmetic processing device such as a computer. The part composed of the adder 80 and the output adjustment unit 90 corresponds to the "output signal generation unit" of the present invention.

[0015] The audio signal processing apparatus 10 is connected to a plurality of speakers SP1 - SP64. Note that FIG. 1 shows an embodiment using 64 speakers, but the number of speakers is not limited to this.

[0016] Audio signals S1 - S96 of a plurality of sound sources OBJ1 - OBJ96 are input to the audio signal processing apparatus 10. Note that FIG. 1 shows an embodiment using 96 sound sources, but the number of sound sources is not limited to this.

[0017] The region setting unit 30 divides the reproduction space into a plurality of regions and sets information (region information) regarding the divided regions. The region information is the position coordinates that determine the boundaries of the regions and the position coordinates of the representative points set in the regions.

[0018] The region setting unit 30 outputs the region information of the plurality of set regions Area1 - Area8 to the grouping unit 40. Note that FIG. 1 shows an embodiment in which the regions are set to eight, but the number of regions is not limited to this.

[0019] The grouping unit 40 groups the sound sources OBJ1 - OBJ96 into a plurality of regions Area1 - Area8. Based on the grouping result, the grouping unit 40 generates region - specific audio signals SA1 - SA8 for each of the regions Area1 - Area8 using the audio signals S1 - S96 of the sound sources OBJ1 - OBJ96. For example, the grouping unit 40 mixes the audio signals of the plurality of sound sources grouped in the region Area1 to generate the region - specific audio signal SA1.

[0020] The grouping unit 40 outputs the plurality of sound signals SA1 - SA8 for each region to the initial reflected sound control signal generation unit 50. Also, the grouping unit 40 outputs the sound signals S1 - S96 of the sound sources OBJ1 - OBJ96 to the mixer 60.

[0021] The initial reflected sound control signal generation unit 50 generates initial reflected sound control signals ER1 - ER64 for each of the plurality of speakers SP1 - SP64 from the plurality of sound signals SA1 - SA8 for each region. The initial reflected sound control signals ER1 - ER64 are signals output to each of the speakers SP1 - SP64 to simulate the initial reflected sound in the virtual space in the reproduction space. The initial reflected sound control signal generation unit 50 outputs the generated initial reflected sound control signals ER1 - ER64 to the adder 80.

[0022] Roughly (detailed configuration and processing will be described later), the initial reflected sound control signal generation unit 50 sets virtual sound sources (virtual sound sources) on the reproduction space using the positions of the speakers SP1 - SP64 arranged in the reproduction space and the geometric shape of the virtual space. Note that the specific setting of the virtual sound sources will be described later. The initial reflected sound control signal generation unit 50 generates the initial reflected sound control signals ER1 - ER64 that simulate the initial reflected sound in the virtual space by using the virtual sound sources. At this time, the initial reflected sound control signal generation unit 50 performs a desired tone color adjustment on the initial reflected sound control signals ER1 - ER64.

[0023] The mixer 60 is a summing mixer. The mixer 60 mixes the sound signals S1 - S96 of the sound sources OBJ1 - OBJ96 to generate a reverberation sound generation signal Sr. The mixer 60 outputs the reverberation sound generation signal Sr to the reverberation sound control signal generation unit 70.

[0024] The reverberation sound control signal generation unit 70 generates reverberation sound control signals REV1 - REV64 for each of the plurality of speakers SP1 - SP64 from the reverberation sound generation signal Sr. The reverberation sound control signals REV1 - REV64 are signals output to each of the speakers SP1 - SP64 to simulate the reverberation sound (rear reverberation sound) in the virtual space in the reproduction space. The reverberation sound control signal generation unit 70 outputs the generated reverberation sound control signals REV1 - REV64 to the adder 80.

[0025] Roughly (detailed configuration and processing will be described later), the reverberation sound control signal generation unit 70 divides the reproduction space into a plurality of reverberation sound setting areas, and generates reverberation sound control signals for each of the plurality of reverberation sound setting areas. The reverberation sound control signal generation unit 70 assigns the plurality of speakers SP1 - SP64 to the plurality of reverberation sound setting areas. The reverberation sound control signal generation unit 70 sets the reverberation sound control signals for each reverberation sound setting area to the plurality of speakers SP1 - SP64 based on this assignment.

[0026] At this time, the reverberation sound control signal generation unit 70 sets the connection timing between the early reflection sound and the reverberation sound based on the geometric shape of the reproduction space. The reverberation sound control signal generation unit 70 gradually increases the level (amplitude) of the reverberation sound control signal in the period before the connection timing, and gradually decreases the level (amplitude) of the reverberation sound control signal in the period after the connection timing.

[0027] The adder 80 adds the early reflection sound control signals and the reverberation sound control signals generated for each of the plurality of speakers SP1 - SP64 to generate speaker signals Sat1 - Sat64 for the plurality of speakers. For example, the adder 80 adds the early reflection sound control signal for speaker SP1 and the reverberation sound control signal for speaker SP1 to generate the speaker signal Sat1. The adder 80 outputs the speaker signals Sat1 - Sat64 for the plurality of speakers to the output adjustment unit 90.

[0028] The output adjustment unit 90 performs gain control and delay control on the plurality of speaker signals Sat1 - Sat64 to generate output signals So1 - So64. The output adjustment unit 90 outputs the output signals So1 - So64 to the plurality of speakers SP1 - SP64. For example, the output adjustment unit 90 performs gain control and delay control for speaker SP1 on the speaker signal Sat1 to generate the output signal So1. The output adjustment unit 90 outputs the output signal So1 to the speaker SP1.

[0029] Schematically (detailed configuration and processing will be described later), the output adjustment unit 90 receives an input of acoustic parameters in the reproduction space. The acoustic parameters are, for example, parameters for setting adjustments such as the spread of the space in the width direction in the sound space, the spread of the space behind the sound reception point in the sound space, and the spread of the space in the ceiling direction in the sound space. Based on the position coordinates of the plurality of speakers SP1 - SP64 and the acoustic parameters, the output adjustment unit 90 collectively sets the gain values and delay amounts (delay quantities) of the plurality of speaker signals Sat1 - Sat64. Collectively setting means not setting individually for each speaker, but rather, for example, by simply inputting the position coordinates of each speaker into a specific calculation formula common to all speakers, the gain values and delay amounts of each speaker are set. The output adjustment unit 90 performs gain control and delay control on the plurality of speaker signals Sat1 - Sat64 using the set gain values and delay values.

[0030] [Outline Processing of Sound Signal Processing Method] FIG. 2 is a flowchart of the sound signal processing method according to an embodiment of the present invention. FIG. 2 shows the sound signal processing method realized by the sound signal processing apparatus 10 of FIG. 1. Note that the content of each process shown in FIG. 2 is described briefly because it has been explained in the description of FIG. 1 above.

[0031] (Grouping of Sound Sources OBJ1 - OBJ96) The grouping unit 40 groups the plurality of sound sources OBJ1 - OBJ96 for each of the plurality of regions Area1 - Area8 (S11).

[0032] (Generation of Early Reflection Sound Control Signal) The early reflection sound control signal generation unit 50 sets the timbre for early reflection sound for each group ( S12 ). The early reflection sound control signal generation unit 50 sets virtual sound sources for each group (S13). The early reflection sound control signal generation unit 50 generates early reflection sound control signals for each of the plurality of speakers SP1 - SP64 using the timbre and the virtual sound sources (S14).

[0033] (Generation of Reverberation Sound Control Signal) The mixer 60 sums the sound signals S1 - S96 of the plurality of sound sources OBJ1 - OBJ96 (S21). The reverberation sound control signal generation unit 70 sets the connection timing between the early reflection sound and the reverberation sound based on the geometric shape of the reproduction space (S22). The reverberation sound control signal generation unit 70 generates a reverberation sound control signal using the set connection timing (S23). The reverberation sound control signal generation unit 70 assigns the generated reverberation sound control signal to the plurality of speakers SP1 - SP64 based on the position coordinates of the plurality of speakers SP1 - SP64 in the reproduction space (S24).

[0034] (Output Processing to a Plurality of Speakers) The adder 80 adds the early reflection sound control signal and the reverberation sound control signal for each of the plurality of speakers SP1 - SP64 to generate speaker signals Sat1 - Sat64 (S31).

[0035] The output adjustment unit 90 generates output signals So1 - So64 from the speaker signals Sat1 - Sat64 using acoustic parameters that realize the localization of reverberation and the spread of the space in the reproduction space (S32). The output adjustment unit 90 outputs the output signals So1 - So64 to the plurality of speakers SP1 - SP64 (S33).

[0036] By using the above - described configuration and processing, the sound signal processing apparatus 10 (sound signal processing method) can obtain the following various effects.

[0037] (1) The sound signal processing apparatus 10 (sound signal processing method) can achieve clear sound image localization and rich spatial expansion by grouping sound sources for each region obtained by dividing the reproduction space to generate early reflection sounds. At this time, the reverberation sound is constant throughout the reproduction space, and only the early reflection sound changes depending on the position of the sound source. Therefore, for example, when the position of the sound source moves, the movement of the sound of this sound source becomes smoother.

[0038] (2) The sound signal processing apparatus 10 (sound signal processing method) can more faithfully simulate the early reflection sound due to the geometric shape of the virtual space in the reproduction space by generating an early reflection sound control signal using virtual sound sources.

[0039] (3) The sound signal processing apparatus 10 (sound signal processing method) can eliminate the unnaturalness of the timbre of the early reflection sound simulated only by virtual sound sources, for example, by performing timbre adjustment of the early reflection sound control signal.

[0040] (4) The sound signal processing apparatus 10 (sound signal processing method) can make the connection from the early reflection sound to the reverberation sound smoother and more natural by setting the connection timing between the early reflection sound control signal and the reverberation sound control signal based on the geometric shape of the reproduction space.

[0041] (5) The sound signal processing apparatus 10 (sound signal processing method) can realize the sound field desired by the user in the reproduction space with easier operation input by collectively adjusting the gain values and delay amounts of the speaker signals Sat1 - Sat64 including the early reflection sound control signal and the reverberation sound control signal.

[0042] [Specific Explanation of Each Signal Processing Unit and Each Process] Hereinafter, a specific explanation of each of the above-mentioned signal processing units and each process will be described. First, for the early reflection sound, reverberation sound, and virtual sound sources necessary for understanding the invention, an explanation will be given with reference to the drawings.

[0043] [Early Reflection Sound and Reverberation Sound] FIG. 3 is a diagram showing a discrete waveform of sound including general direct sound, early reflected sound, and reverberant sound (late reverberant sound). For example, a hall where performance or content playback is performed has an enclosed space surrounded by walls. When sound is generated in this enclosed space, direct sound, early reflected sound, and reverberant sound (late reverberant sound) reach the sound receiving point.

[0044] Direct sound is the sound that directly reaches the sound receiving point from the sound generation position.

[0045] Early reflected sound is the sound that reaches the sound receiving point at an early time after the sound generated at the generation position is reflected by the wall, floor, or ceiling. Therefore, the early reflected sound reaches the sound receiving point following the direct sound. Also, the volume (level) of the early reflected sound is smaller than the volume (level) of the direct sound. If the number of reflections is 1, it is the first-order reflected sound, and if it is n, it is the nth-order reflected sound. The arrival direction and volume of the early reflected sound at the sound receiving point are greatly affected by the sound generation position.

[0046] Reverberant sound reaches the sound receiving point following the early reflected sound. Reverberant sound is the sound that reaches the sound receiving point after the sound generated at the generation position is multiply reflected. That is, reverberant sound is the sound that reaches the sound receiving point while the reflected sound is reflected and attenuated a large number of times. Therefore, the volume (level) of the reverberant sound is smaller than the volume (level) of the early reflected sound. Furthermore, the arrival direction and volume of the reverberant sound are less affected by the sound generation position compared to the early reflected sound.

[0047] [Virtual sound source] FIGS. 4(A) and 4(B) are diagrams showing the setting concept of a virtual sound source. Note that in FIGS. 4(A) and 4(B), for ease of explanation, the setting concept of the virtual sound source in two dimensions is shown, but the virtual sound source can be set with the same concept in three dimensions. That is, in the actual playback space, when the sound sources are not aligned on a plane but are spatially arranged and the virtual space is set three-dimensionally, the virtual sound source is set three-dimensionally.

[0048] In the reproduction space, there are a sound source SS and a sound reception point RP. Note that the sound source SS shown in FIGS. 4(A) and 4(B) has a different meaning from the sound source OBJ in the above description, and means a device that generates general sound. Also, in the reproduction space, a virtual wall IWL for realizing the sound field of the virtual space is set. The virtual wall IWL is obtained from the geometric shape of the virtual space.

[0049] The sound source SS and the sound reception point RP exist within the space surrounded by the virtual wall IWL. The virtual wall IWL includes a virtual wall IWL1, a virtual wall IWL2, a virtual wall IWL3, and a virtual wall IWL4. The virtual wall IWL1 and the virtual wall IWL4 are arranged so as to sandwich the sound source SS and the sound reception point RP in the first direction (the vertical direction in FIGS. 4(A) and 4(B)) of the reproduction space. The virtual wall IWL1 is arranged on the side closer to the sound source SS than the sound reception point RP, and the virtual wall IWL4 is arranged on the side closer to the sound reception point RP than the sound source SS. The virtual wall IWL2 and the virtual wall IWL3 are arranged so as to sandwich the sound source SS and the sound reception point RP in the second direction (the horizontal direction in FIGS. 4(A) and 4(B)) of the reproduction space. The virtual wall IWL2 is arranged on the side closer to the sound source SS than the sound reception point RP, and the virtual wall IWL3 is arranged on the side closer to the sound reception point RP than the sound source SS.

[0050] If the virtual walls IWL1, IWL2, IWL3, and IWL4 were walls that actually reflect sound, as shown in FIG. 4(B), the sound emitted from the sound source SS would be reflected by the virtual walls IWL1, IWL2, and IWL3 and reach the sound reception point RP. Note that although the reflection from the virtual wall IWL4 is not shown in FIG. 4(B), reflection also occurs at the virtual wall IWL4 in the same manner as the virtual walls IWL1, IWL2, and IWL3.

[0051] However, the virtual walls IWL1, IWL2, IWL3, and IWL4 do not actually exist in the reproduction space. Therefore, as shown in FIG. 4(A), the sound signal processing device 10 sets virtual sound sources IS1, IS2, and IS3 assuming that the reflection of sound on the wall surface is specular reflection.

[0052] Specifically, the sound signal processing device 10 sets a virtual sound source IS1 at a position that is line-symmetric with respect to the sound source SS with the virtual wall IWL1 as the reference line. The sound signal processing device 10 sets a virtual sound source IS2 at a position that is line-symmetric with respect to the sound source SS with the virtual wall IWL2 as the reference line. A virtual sound source IS3 is set at a position that is line-symmetric with respect to the sound source SS with the virtual wall IWL3 as the reference line. Note that by adjusting the acoustic power of each virtual sound source IS, the energy loss in the reflection at the virtual wall IWL can be simulated.

[0053] By making such settings, the sound generated by the virtual sound source IS1 becomes the same as the sound generated by the sound source SS and reflected by the virtual wall IW1. The sound generated by the virtual sound source IS2 becomes the same as the sound generated by the sound source SS and reflected by the virtual wall IW2. The sound generated by the virtual sound source IS3 becomes the same as the sound generated by the sound source SS and reflected by the virtual wall IW3. Note that in FIGS. 4(A) and 4(B), the virtual sound sources with respect to the virtual wall IWL4 are not shown, but for the virtual wall IWL4 as well, virtual sound sources can be set in the same manner as the virtual wall IWL1, the virtual wall IWL2, and the virtual wall IWL3.

[0054] By setting the virtual sound sources in this way, the sound signal processing device 10 can simulate the early reflected sound in the virtual space in a playback space where there is no actual wall in the virtual space.

[0055] [Configuration and Processing of Grouping Unit 40] FIG. 5 is a functional block diagram showing an example of the configuration of the grouping unit 40. FIG. 6 is a flowchart showing a method for grouping sound sources.

[0056] As shown in FIG. 5, the grouping unit 40 includes a sound source position detection unit 41, a region determination unit 42, and a matrix mixer 400.

[0057] The sound source position detection unit 41 detects the position coordinates of a plurality of sound sources OBJ1-OBJ96 in the reproduction space (Fig. 6: S111). For example, the sound source position detection unit 41 detects the position coordinates of the sound sources OBJ1-OBJ96 by an operation input from the user. Alternatively, the sound source position detection unit 41 is provided with position detection sensors for detecting the sound sources OBJ1-OBJ96, and detects the position coordinates of the sound sources OBJ1-OBJ96 based on the positions detected by the position detection sensors.

[0058] The sound source position detection unit 41 outputs the position coordinates of the sound sources OBJ1-OBJ96 to the region determination unit 42.

[0059] The region determination unit 42 groups the sound sources OBJ1-OBJ96 into a plurality of regions Area1-Area8 using the region information of the plurality of regions Area1-Area8 from the region setting unit 30 and the position coordinates of the sound sources OBJ1-OBJ96 from the sound source position detection unit 41 (Fig. 6: S112). More specifically, the region determination unit 42 performs grouping as follows.

[0060] Fig. 7 is a diagram showing the concept of grouping a plurality of sound sources into a plurality of regions. In Fig. 7, the upper part of the figure is the front of the hall which is the reproduction space, and the lower part of the figure is the rear of the hall.

[0061] The region setting unit 30 sets a reference point Pso for region division with respect to the reproduction space. For example, as shown in Fig. 7, the region setting unit 30 sets the center position of the hall that realizes the reproduction space as the reference point Pso. Note that the region setting unit 30 can also use a point (position) set by the user as the reference point. For example, the region setting unit 30 can use a sound reception point or the like set by the user as the reference point.

[0062] The area setting unit 30 sets eight areas Area1 - Area8 so as to divide the entire circumference on the plane into eight parts with the reference point Pso for area division as the center. For example, in the case of FIG. 7, the area setting unit 30 sets a plurality of areas Area1, Area2, and Area3 in front of the reference point Pso in the hall (reproduction space). Also, the area setting unit 30 sets the area Area4 to the left from the reference point Pso facing forward in front of the hall, and sets the area Area5 to the right from the reference point Pso facing forward in front of the hall. Further, the area setting unit 30 sets a plurality of areas Area6, Area7, and Area8 behind the reference point Pso in the hall (reproduction space).

[0063] Note that this area setting is an example, and other settings may be used as long as the entire reproduction space can be covered by the set plurality of areas. Also, this description shows the setting of planar areas, but spatial areas can be set in the same way. For example, the vertical range of the area Area1 is also included in the area Area1.

[0064] The area setting unit 30 sets representative points RP1 - RP8 for each of the plurality of areas Area1 - Area8. For example, the area setting unit 30 sets the plurality of representative points RP1 - RP8 at the center positions of the plurality of areas Area1 - Area8. Or, in the case of an area that spreads radially as shown in FIG. 7, for example, the area setting unit 30 sets the representative point at a position at a predetermined distance from the reference point Pso on a straight line passing through the center of the radially spreading angle. Note that these methods of setting the representative points are examples, and other methods may be used as long as one representative point can be set for one area and the grouping process of the sound sources can be surely performed.

[0065] The area setting unit 30 outputs the area information of the plurality of areas Area1 - Area8 to the area determination unit 42 of the grouping unit 40 and the matrix mixer 400. The area information of the plurality of areas Area1 - Area8 is the position coordinates of the representative points RP1 - RP8 of the areas Area1 - Area8, the coordinate information representing the boundary lines forming the shapes of the areas Area1 - Area8, and the like.

[0066] (Method for grouping sound sources into regions using representative points) FIG. 8(A) is a flowchart showing a method for grouping sound sources using representative points.

[0067] The region determination unit 42 acquires the position coordinates of the representative points RP1 - RP8 from the region information of the plurality of regions Area1 - Area8 ( S1121 ). The region determination unit 42 calculates the distances between the position coordinates of the sound source to be determined for grouping and the position coordinates of the representative points RP1 - RP8 ( S1122 ). The region determination unit 42 groups the sound source into the region including the representative point with the shortest distance ( S1123 ).

[0068] For example, in the case of the sound source OBJ1 in the example of FIG. 7, the region determination unit 42 detects the position coordinates of the sound source OBJ1 and acquires the position coordinates of the plurality of representative points RP1 - RP8. The region determination unit 42 calculates the distances between the sound source OBJ1 and the plurality of representative points RP1 - RP8 from the position coordinates of the sound source OBJ1 and the position coordinates of the plurality of representative points RP1 - RP8, respectively. The region determination unit 42 detects that the distance between the sound source OBJ1 and the representative point RP1 is shorter than the distances between the sound source OBJ1 and the other representative points RP2 - RP8. In other words, the region determination unit 42 detects that the distance between the sound source OBJ1 and the representative point RP1 is the shortest distance. The region determination unit 42 groups the sound source OBJ1 into the region Area1 associated with the representative point RP1.

[0069] (Method for grouping sound sources into regions using the boundaries of regions) FIG. 8(B) is a flowchart showing a method for grouping sound sources using the boundaries of regions.

[0070] The region determination unit 42 acquires the coordinate information (boundary coordinates) representing the boundary lines of the respective regions Area1 - Area8 from the region information of the plurality of regions Area1 - Area8 ( S1124 ). The region determination unit 42 determines whether the position coordinates of the sound source to be determined for grouping are inside the respective regions Area1 - Area8 ( S1125)。For example, the area determination unit 42 uses the Crossing Number Algorithm to determine whether the sound source is inside or outside the area. If the sound source is inside the area ( S1125: YES ), it groups the sound source into this area ( S1126 ).

[0071] For example, in the case of the sound source OBJ1 in the example of FIG. 7, the area determination unit 42 detects the position coordinates of the sound source OBJ1 and acquires the coordinate information (boundary coordinates) representing the boundary lines of the plurality of areas Area1 - Area8. The area determination unit 42 performs an inside / outside determination of the sound source OBJ1 with respect to the plurality of areas Area1 - Area8 based on the position coordinates of the sound source OBJ1 and the boundary coordinates of the plurality of areas Area1 - Area8. The area determination unit 42 detects that the sound source OBJ1 is inside the area Area1. The area determination unit 42 groups the sound source OBJ1 into the area Area1.

[0072] The area determination unit 42 groups the plurality of input sound sources OBJ1 - OBJ96 into the plurality of areas Area1 - Area8. For example, in the example of FIG. 7, the area determination unit 42 groups the sound sources OBJ1 and OBJ4 into the area Area1, groups the sound source OBJ2 into the area Area2, and groups the sound source OBJ3 into the area Area5.

[0073] The area determination unit 42 outputs the grouping information to the matrix mixer 400. The grouping information is the information indicating which sound source is grouped into which area as described above.

[0074] The matrix mixer 400 generates area-specific audio signals SA1 - SA8 for each of the plurality of areas Area1 - Area8 using the audio signals S1 - S96 of the plurality of sound sources OBJ1 - OBJ96 based on the grouping information. For example, if a plurality of sound sources are grouped in an area, the matrix mixer 400 mixes the audio signals of these plurality of sound sources to generate the area-specific audio signal for this area. The matrix mixer 400 outputs the area-specific audio signal of each area to the early reflection sound control signal generation unit 50. Note that if even one sound source is grouped in an area, the matrix mixer 400 outputs the audio signal of this sound source as the area-specific audio signal of this area to the early reflection sound control signal generation unit 50.

[0075] In the example of FIG. 7, in area Area1, sound sources OBJ1 and OBJ4 are grouped. The matrix mixer 400 mixes the audio signal S1 of sound source OBJ1 and the audio signal S4 of sound source OBJ4 to generate and output the area-specific audio signal SA1 of area Area1. Also, in area Area2, sound source OBJ2 is grouped. The matrix mixer 400 outputs the audio signal S2 of sound source OBJ2 as the area-specific audio signal SA2 of area Area2. Also, in area Area5, sound source OBJ3 is grouped. The matrix mixer 400 outputs the audio signal S3 of sound source OBJ3 as the area-specific audio signal SA5 of area Area5.

[0076] By realizing such a configuration and processing, the audio signal processing apparatus 10 can group a plurality of sound sources for each of the plurality of areas that divide the sound space and generate an early reflection sound control signal. Thereby, the audio signal processing apparatus 10 can reproduce the early reflection sound according to the position of the sound source, and realize clear sound image localization and a rich spatial spread.

[0077] Note that in the above description, the case where the sound source moves is not shown in detail. However, when the sound source moves, the grouping unit 40 performs the processing shown in FIG. 9. FIG. 9 is a flowchart showing an example of a method of grouping due to the movement of the sound source.

[0078] The sound source position detection unit 41 detects the movement of the sound source (S104). The sound source position detection unit 41 detects the movement of the sound source, for example, by an operation input from the user. Alternatively, the sound source position detection unit 41 detects the movement of the sound source by continuously detecting the sound source position with a position detection sensor. Then, the area determination unit 42 performs grouping again on the moved sound source (S105). The sound source position detection unit 41 detects the position coordinates of the sound source after the movement and outputs them to the area determination unit 42.

[0079] The area determination unit 42 performs grouping into a plurality of areas Area1 - Area8 as described above using the position coordinates of the sound source after the movement. (S105) .

[0080] By performing such processing, the sound signal processing device 10 can generate an initial reflected sound control signal corresponding to the position of the sound source after the movement even if the sound source moves. Thereby, the sound signal processing device 10 can reproduce the change in the initial reflected sound according to the movement of the sound source, and can realize a clear sound image localization and a rich spatial expansion corresponding to the movement of the sound source even if there is a movement of the sound source.

[0081] Also, when such a movement of the sound source occurs, the sound signal processing device 10 can perform cross-fade processing on the initial reflected sound control signal before the movement and the initial reflected sound control signal after the movement. For example, when the sound source moves, the sound signal processing device 10 gradually lowers the component of the sound signal of this sound source in the area-specific sound signal where the sound source before the movement is included. On the other hand, the sound signal processing device 10 gradually raises the component of the sound signal of this sound source in the area-specific sound signal where the sound source after the movement is included.

[0082] By performing such processing, the sound signal processing device 10 can suppress a discontinuous change in the initial reflected sound when the sound source moves. Thereby, the sound signal processing device 10 can change the initial reflected sound more smoothly according to the movement of the sound source when the sound source moves.

[0083] Also, the matrix mixer 400 outputs the sound signals S1 - S96 of a plurality of sound sources OBJ1 - OBJ96 to the mixer 60. As described above, the mixer 60 AdditionIt generates a signal Sr for generating reverberation sound and outputs it to the reverberation sound control signal generation unit 70. The reverberation sound control signal generation unit 70 generates reverberation sound control signals REV1-REV64 using the signal Sr for generating reverberation sound.

[0084] Through such processing, the reverberation sound is not affected by the position or movement of the sound source. Therefore, the sound signal processing apparatus 10 can more clearly reproduce the movement of the sound source due to the change in the early reflection sound while keeping the reverberation sound in the reproduction space constant even when the sound source moves.

[0085] [Generation of Early Reflection Sound Control Signal] FIG. 10 is a functional block diagram showing an example of the configuration of the early reflection sound control signal generation unit 50. FIG. 11 is a diagram showing an example of the GUI.

[0086] As shown in FIG. 10, the early reflection sound control signal generation unit 50 includes an FIR filter circuit 51, an LDtap circuit 52, an addition processing unit 53, a timbre setting unit 501, an imaginary sound source setting unit 502, and an operation unit 500. The LDtap circuit 52 is a circuit that amplifies and delays an input signal and outputs it. The FIR filter circuit 51 includes a plurality of FIR filters 511-518. The LDtap circuit 52 includes a plurality of LDtaps 521-528, an output speaker setting unit 5201, and a coefficient setting unit 5202. Note that the connection order of the FIR filter circuit 51 and the LDtap circuit 52 may be reversed.

[0087] [Timbre Adjustment of Early Reflection Sound] The operation unit 500 receives designation information of the timbre to be added to the early reflection sound from the user and outputs it to the timbre setting unit 501. The designation information of the timbre is, for example, information (information representing filter characteristics) specifying emphasis on the low frequency range, emphasis on the high frequency range, volume of the early reflection sound, attenuation characteristics of the early reflection sound, etc.

[0088] As a specific example, the operation unit 500 receives operations through a GUI100 (Graphical User Interface) as shown in FIG. 11.

[0089] GUI 100It includes a setting display window 111, a plurality of operators 112, a knob 1131, and an adjustment value display window 1132.

[0090] The setting display window 111 displays the shape of the virtual wall IWL of the virtual space set by the plurality of operators 112 and the knob 1131. At this time, the setting display window 111 can display the position of the separately set sound source SS, the position of the speaker SP, the position of the sound reception point RP, and the coordinate axes of the reproduction space together with the virtual wall IWL.

[0091] The plurality of operators 112 are associated with samples (various halls, rooms, etc.) of the preset virtual space. Although not shown in the figure, each of the plurality of operators 112 has an index (for example, hall name, etc.) that indicates the sample of the virtual space associated with that operator 112.

[0092] The knob 1131 is Of the virtual space for setting the room size (Size of the space) The adjustment value display window 1132 displays the set value of the room size. Of the virtual space

[0093] The GUI 100 accepts various operations for adjusting the tone color. For example, the GUI 100 includes a plurality of operators 112, an operator for the bass range, an operator for the treble range, an operator for volume adjustment, an operator for attenuation characteristic adjustment, etc., and accepts operations by these operators.

[0094] When the user operates a desired operator using the GUI 100, the operation unit 500 detects this operation and sets the specified information of the tone color according to these operations.

[0095] For example, when the operation unit 500 accepts the selection of a plurality of operators 112, it acquires the specified information of the tone color preset in the virtual space associated with this operator 112. Also, when the operation unit 500 accepts operations by an operator for the bass range, an operator for the treble range, an operator for volume adjustment, an operator for attenuation characteristic adjustment, etc., it acquires the specified information of the tone color set by these operators.

[0096] Although not shown in the figure, the GUI 100 can also display the tone color designation information using, for example, the filter coefficients of the FIR filters 511 - 518 described later, a schematic waveform, etc. In this case, when the GUI 100 receives an adjustment of the tone color designation information, it can also change the display according to this adjustment. For example, the GUI 100 can change the display of the waveform according to the adjustment.

[0097] The tone color setting unit 501 sets the filter coefficients of the FIR filters 511 - 518 of the FIR filter circuit 51 based on the tone color designation information. For example, when the tone color setting unit 501 receives the designation information emphasizing the bass range, it sets the filter coefficients with the low frequency range of the FIR filters 511 - 518 of the FIR filter circuit 51 boosted. Also, when the tone color setting unit 501 receives the designation information emphasizing the high frequency range, it sets the filter coefficients with the high frequency range of the FIR filters 511 - 518 of the FIR filter circuit 51 boosted. The tone color setting unit 501 outputs the set filter coefficients to the FIR filter circuit 51. Note that the tone color setting unit 501 can set and adjust not only the filter coefficients but also the sampling frequency and filter length as filter characteristics.

[0098] Also, the tone color setting unit 501 sets the gain values of each tap of the FIR filters 511 - 518 of the FIR filter circuit 51 based on the tone color designation information. The tone color setting unit 501 outputs the set gain values to the FIR filter circuit 51.

[0099] The plurality of FIR filters 511 - 518 are filters corresponding to the sound signals SA1 - SA8 for each region. The sound signals SA1 - SA8 for each region are input to the FIR filters 511 - 518. For example, as shown in FIG. 10, the sound signal SA1 for each region is input to the FIR filter 511, the sound signal SA2 for each region is input to the FIR filter 512, the sound signal SA3 for each region is input to the FIR filter 513, and the sound signal SA4 for each region is input to the FIR filter 514. The sound signal SA5 for each region is input to the FIR filter 515, the sound signal SA6 for each region is input to the FIR filter 516, the sound signal SA7 for each region is input to the FIR filter 517, and the sound signal SA8 for each region is input to the FIR filter 518.

[0100] The plurality of FIR filters 511 - 518 have the same number of taps. For example, the plurality of FIR filters 511 - 518 have 16000 taps. Note that this number of taps is an example, and it may be set based on the resource conditions of the sound signal processing device 10, the accuracy of the timbre of the initial reflected sound to be reproduced, etc.

[0101] The plurality of FIR filters 511 - 518 perform filtering processing (convolution operation) on the plurality of sound signals SA1 - SA8 for each region according to the filter coefficients and gain values set by the timbre setting unit 501. As a result, the plurality of FIR filters 511 - 518 generate the sound signals SA1f - SA8f for each region after the filtering process. For example, the FIR filter 511 performs filtering processing (convolution operation) on the sound signal SA1 for each region according to the filter coefficients and gain values set by the timbre setting unit 501, and generates the sound signal SA1f for each region after the filtering process. Similarly, the plurality of FIR filters 512 - 518 individually generate the sound signals SA2f - SA8f for each region after the filtering process from the sound signals SA2 - SA8 for each region.

[0102] The plurality of FIR filters 511 - 518 output the region - specific sound signals SA1f - SA8f after filter processing to the plurality of LDtaps 521 - 528. For example, the FIR filter 511 outputs the region - specific sound signal SA1f after filter processing to the LDtap 521. Similarly, the plurality of FIR filters 512 - 518 output the region - specific sound signals SA2f - SA8f after filter processing to the plurality of LDtaps 522 - 528.

[0103] Note that the tone color designation information is not limited to the importance information of the sound range, but also includes information for making the waveform of the early reflected sound have the desired characteristics of the user. By using such tone color designation information, the sound signal processing apparatus 10 can realize more diverse early reflected sounds with tones according to the user's preferences.

[0104] [Virtual sound source setting and LDtap setting] The virtual sound source setting unit 502 sets a virtual sound source based on the position coordinates of the sound receiving point in the reproduction space and the geometric shape of the virtual space.

[0105] FIG. 12 is a flowchart showing an example of the virtual sound source setting process. The virtual sound source setting unit 502 acquires the position coordinates of the sound receiving point in the reproduction space (S131). For example, the virtual sound source setting unit 502 acquires the position coordinates of the sound receiving point in the reproduction space by an operation input from the user, detection of the position by a position detection sensor, etc.

[0106] The virtual sound source setting unit 502 acquires the geometric shape of the virtual space (S132). For example, the virtual sound source setting unit 502 acquires the geometric shape of the virtual space by an operation input from the user, etc. The geometric shape of the virtual space includes a coordinate group representing the shape of the wall arranged in the virtual space, etc.

[0107] The virtual sound source setting unit 502 is connected to the GUI 100. When the user selects a desired operator 112 from the plurality of operators 112, the GUI 100 reads and acquires the geometric shape of the virtual space associated with this operator 112. Also, when the user adjusts the room size using the knob 1131, the GUI 100 acquires the adjustment value of this room size.

[0108] Based on each setting thus obtained by the GUI 100, the virtual sound source setting unit 502 acquires the position coordinates of the geometric shape of the virtual space in which the room size is set. Further, the virtual sound source setting unit 502 acquires the position coordinates of the sound source SS and the receiving point RP (room center (Center position of the space) ). Using these acquired pieces of information, the virtual sound source setting unit 502 sets a virtual sound source as follows . Virtual The sound source setting unit 502 aligns the coordinate system of the reproduction space with the coordinate system of the virtual space. Using the position coordinates of the receiving point in the reproduction space and the geometric shape of the virtual space, the virtual sound source setting unit 502 sets the position coordinates of the virtual sound source in the reproduction space according to the concept using FIGS. 4(A) and 4(B) described above (S133).

[0109] FIGS. 13(A) and 13(B) are diagrams showing setting examples of respective virtual sound sources when the geometric shapes are different. In FIG. 13(A), it is a rectangular virtual wall IWL, and in FIG. 13(B), it is a hexagonal virtual wall IWLh.

[0110] As described above, when the geometric shape of the virtual space is different, even if the position coordinates of the sound source SSa and the receiving point RP do not change, the positional relationships between the sound source SSa and the receiving point RP and the virtual wall IWL, and between the sound source SSa and the receiving point RP and the virtual wall IWLh are different. Thereby, the positions of the virtual sound sources IS1a, IS2a, and IS3a set in the case of FIG. 13(A) are different from the positions of the virtual sound sources IS1ah, IS2ah, and IS3ah set in FIG. 13(B).

[0111] FIGS. 14(A), 14(B), and 14(C ) is are diagrams showing setting examples of virtual sound sources. FIGS. 14(A), 14(B), and 14(C) are Of the virtual sound sourceThis is a diagram showing the change in the plane. Fig. 14(B) shows a case where the position of the sound source SSa with respect to the reference point (sound reception point RP) is the same as that in Fig. 14(A), but the size of the virtual space is different. Fig. 14(C) shows a case where the size of the virtual space is the same as that in Fig. 14(A), but the positional relationship between the reference point of the virtual space and the reference point (sound reception point) of the reproduction space has changed (when the room center of the reproduction space has changed).

[0112] As can be seen from the comparison results between Fig. 14(A) and Fig. 14(B), due to the difference in the size of the virtual space on the reproduction space (described as the virtual wall IWL in Fig. 14(A) and the virtual wall IWLc in Fig. 14(B)), the distance and positional relationship between the sound source that is the origin of the virtual sound source SSa and the virtual wall are different. As a result, the positions of the virtual sound sources IS1a, IS2a, and IS3a set in the case of Fig. 14(A) are different from the positions of the virtual sound sources IS1c, IS2c, and IS3c set in the case of Fig. 14(B).

[0113] Also, as can be seen from the comparison results between Fig. 14(A) and Fig. 14(C), due to the change in the positional relationship between the reference point of the virtual space and the sound reception point RP, the positions of the virtual sound sources on the reproduction space (the positions of the virtual sound sources with respect to the sound reception point RP and the speakers) move. As a result, the positions of the virtual sound sources IS1a, IS2a, and IS3a set in the case of Fig. 14(A) are different from the positions of the virtual sound sources IS1as, IS2as, and IS3as set in the case of Fig. 14(C).

[0114] Figs. 15(A), 15(B), and 15(C) are diagrams showing examples of setting virtual sound sources. . Figure Figs. 15(A), 15(B), and 15(C) show the height Position of the virtual sound source in the direction of change.

[0115] The ceiling heights are different between Fig. 15(A) and Fig. 15(B). That is, the distance (height) from the virtual floor wall IWFL of the floor to the virtual ceiling wall IWCL of the virtual wall IWL shown in Fig. 15(A) is different from the distance (height) from the virtual floor wall IWFL of the floor to the virtual ceiling wall IWCLL of the virtual wall IWLL shown in Fig. 15(B).

[0116] As can be seen from the comparison results between FIGS. 15(A) and 15(B), the height of the ceiling is different, so the distances and positional relationships between the sound source that is the origin of the virtual sound source and the virtual walls IWCL and IWCLL of the ceiling are different. As a result, the position of the virtual sound source IS1Ca set in the case of FIG. 15(A) is different from the position of the virtual sound source IS1CaL set in the case of FIG. 15(B).

[0117] In FIGS. 15(A) and 15(C), the shapes of the ceilings are different. That is, the shape of the virtual wall IWCL of the ceiling in the virtual wall IWL shown in FIG. 15(A) is different from the shape of the virtual wall IWCLx of the ceiling in the virtual wall IWLx shown in FIG. 15(C).

[0118] As can be seen from the comparison results between FIGS. 15(A) and 15(C), the shape of the ceiling is different, so the positional relationships between the sound source that is the origin of the virtual sound source and the virtual walls IWCL and IWCLx of the ceiling are different. As a result, the position of the virtual sound source IS1Ca set in the case of FIG. 15(A) is different from the position of the virtual sound source IS1Cax set in the case of FIG. 15(C).

[0119] In this way, the virtual sound source setting unit 502 can optimally set the position of the virtual sound source in the reproduction space corresponding to the geometric shape of the virtual space and the positional relationship between the reproduction space and the virtual space. As a result, the sound signal processing device 10 can clarify the sound image localization of the early reflected sound corresponding to the position coordinates of the speakers in the reproduction space, the geometric shape of the virtual space, and the positional relationship between the reproduction space and the virtual space.

[0120] The virtual sound source setting unit 502 outputs the position coordinates of the virtual sound source set for each of the plurality of regions Area1 - Area8 to the output speaker setting unit 5201 of the LDtap circuit 52.

[0121] The output speaker setting unit 5201 sets the virtual sound source IS to be assigned to each speaker based on the position coordinates of the virtual sound source IS, the position coordinates of the sound reception point RP, and the position coordinates of the plurality of speakers SP1 - SP64. FIG. 16 is a flowchart showing the process of assigning the virtual sound source to the speakers.

[0122] The output speaker setting unit 5201 acquires the position coordinates of the virtual sound source from the virtual sound source setting unit 502 (S141). The output speaker setting unit 5201 acquires the position coordinates of the sound reception point in the playback space, for example, by an operation input from the user or the like (S142). The output speaker setting unit 5201 acquires the position coordinates of a plurality of speakers SP1 - SP64, for example, by an operation input from the user or the like (S143).

[0123] The output speaker setting unit 5201 sets the responsible area of the virtual sound source for each speaker based on the positional relationship between the sound reception point RP and the plurality of speakers SP1 - SP64 in the playback space (S144).

[0124] More specifically, the output speaker setting unit 5201 sets the responsible area of the virtual sound source for each speaker as follows. FIGS. 17(A) and 17(B) are diagrams showing the concept of allocating virtual sound sources to speakers. FIG. 17(A) shows the concept of allocation using the azimuth angle φ, and FIG. 17(B) shows the concept of allocation using the elevation angle θ. Also, hereinafter, the speaker SP1 will be described as an example, but the output speaker setting unit 5201 sets the responsible area for the other speakers SP2 - SP64 in the same manner.

[0125] The output speaker setting unit 5201 sets a straight line (the dashed line in FIG. 17(A)) passing through the sound reception point RP and the speaker SP1 using the position coordinates of the sound reception point RP and the position coordinates of the speaker SP1. As shown in FIG. 17(A), the output speaker setting unit 5201 sets an azimuth angle φ that spreads toward the speaker SP1 side with the sound reception point RP as the reference point on the plane with respect to this straight line (the dashed line in FIG. 17(A)). The azimuth angle φ is the angle made in the horizontal direction with respect to the straight line passing through the sound reception point RP and the speaker SP1. Also, as shown in FIG. 17(B), the output speaker setting unit 5201 sets an elevation angle θ that spreads in the vertical direction perpendicular to the plane with respect to the above-mentioned straight line (the dashed line in FIG. 17(B)). The elevation angle θ is the angle made in the vertical direction (the direction perpendicular to the horizontal direction) with respect to the straight line passing through the sound reception point RP and the speaker SP1.

[0126] The output speaker setting unit 5201 is determined by this azimuth angle φ and elevation angle θ Boundary (the boundary surface that determines the horizontal area, the boundary that determines the vertical area plane ) The space on the speaker SP1 side rather than this plane is set as the assigned area RGSP1 of the speaker SP1.

[0127] The output speaker setting unit 5201 acquires the position coordinates of a plurality of virtual sound sources IS (in the case of FIG. 17, a plurality of virtual sound sources ISa - ISg).

[0128] The output speaker setting unit 5201 determines whether or not the plurality of virtual sound sources ISa - ISg are within the assigned area RGSP1 by using the position coordinates of the plurality of virtual sound sources ISa - ISg and the coordinates representing the assigned area RGSP1. This determination can be realized by the same method as the grouping of the above-described sound sources into areas.

[0129] By performing this determination process, the output speaker setting unit 5201, for example, in the case shown in FIG. 14 (A), Figure 14 (B), Figure 14 (C) determines that the plurality of virtual sound sources ISa, ISb, ISc, ISd are within the assigned area RG sp 1, and determines that the plurality of virtual sound sources ISe, ISf, ISg are outside the assigned area RG sp 1.

[0130] The output speaker setting unit 5201 assigns the plurality of virtual sound sources ISa, ISb, ISc, ISd determined to be within the assigned area RG sp 1 to the speaker SP1. (S145) .

[0131] The output speaker setting unit 5201 outputs the assignment information of the plurality of virtual sound sources with respect to the plurality of speakers SP1 - SP64 to the coefficient setting unit 5202. At this time, the output speaker setting unit 5201 outputs the position coordinates of the sound reception point RP, the position coordinates of the plurality of speakers SP1 - SP64, and the position coordinates of the plurality of virtual sound sources to the coefficient setting unit 5202 together with the assignment information.

[0132] Incidentally, the azimuth angle φ is, for example, 60°, and the elevation angle θ is, for example, 45°. The angles of the azimuth angle φ and the elevation angle θ are just examples and can be set and adjusted, for example, by an operation input from the user.

[0133] The coefficient setting unit 5202 sets the tap coefficients to be given to LDtap521 - 528 using the distances between the sound reception point RP and the plurality of speakers SP1 - SP64 and the distance between the sound reception point RP and the virtual sound source IS. The tap coefficients to be given to LDtap521 - 528 are the gain values and delay amounts of LDtap521 - 528.

[0134] FIG. 18 is a flowchart showing the coefficient setting process of LDtap. FIGS. 19(A) and 19(B) are diagrams for explaining the concept of coefficient setting.

[0135] The coefficient setting unit 5202 calculates the distances (speaker distances) between the sound reception point PR and the plurality of speakers SP1 - SP64 using the position coordinates of the sound reception point RP and the position coordinates of the plurality of speakers SP1 - SP64 (S151).

[0136] The coefficient setting unit 5202 calculates the distances (virtual sound source distances) between the sound reception point PR and the plurality of virtual sound sources IS (S152).

[0137] The coefficient setting unit 5202 compares the speaker distances with the virtual sound source distances for the plurality of speakers SP1 - SP64 and the plurality of virtual sound sources IS respectively assigned to these speakers SP1 - SP64 (S153). For example, in the example of FIG. 17(A), the speaker distances and the virtual sound source distances are compared for the speaker SP1 and the plurality of virtual sound sources ISa, ISb, ISc, ISd.

[0138] If the speaker distance is less than or equal to the virtual sound source distance (S153: YES), the coefficient setting unit 5202 uses the virtual sound source distance as it is to set the tap coefficient (S154).

[0139] For example, in the case shown in FIG. 19(A), the virtual sound source ISa is farther from the sound reception point RP than the speaker SP1, and the virtual sound source distance Lia between the sound reception point RP and the virtual sound source ISa is greater than the speaker distance Ls1 between the sound reception point RP and the speaker SP1.

[0140] In this case, the coefficient setting unit 5202 sets the tap coefficient using the distance Da1 between the virtual sound source ISa and the speaker SP1. Specifically, the coefficient setting unit 5202 sets the gain value and the delay amount to be set for the virtual sound source ISa according to the distance Da1. The coefficient setting unit 5202 sets the gain value to be smaller as the distance Da1 is larger, and sets the delay amount to be larger as the distance Da1 is larger.

[0141] If the speaker distance is greater than the virtual sound source distance (S153: NO), the coefficient setting unit 5202 determines whether to reproduce this virtual sound source. In other words, the coefficient setting unit 5202 determines whether to reproduce the virtual sound source on the sound reception point side of the speaker (S155).

[0142] If the coefficient setting unit 5202 is to reproduce the virtual sound source closer to the sound reception point than the speaker (S155: YES), it moves the position of this virtual sound source (S156). More specifically, the coefficient setting unit 5202 moves the position of the virtual sound source on the sound reception point side of the speaker to a position farther from the sound reception point than the speaker. At this time, the coefficient setting unit 5202 moves the position of the virtual sound source using the distance difference between the virtual sound source and the speaker. The coefficient setting unit 5202 sets the tap coefficient using the position coordinates of the virtual sound source after the movement (S157).

[0143] For example, in the case shown in FIG. 19(B), the virtual sound source ISd is closer to the sound reception point RP than the speaker SP1, and the virtual sound source distance Lid between the sound reception point RP and the virtual sound source ISd is smaller than the speaker distance Ls1 between the sound reception point RP and the speaker SP1.

[0144] In this case, the coefficient setting unit 5202 moves the virtual sound source ISd using the distance difference Dd between the virtual sound source distance Lid and the speaker distance Ls1. More specifically, the coefficient setting unit 5202 moves the virtual sound source ISd to a position with a distance difference Dd on the straight line passing through the sound reception point RP and the speaker SP1 and on the side opposite to the sound reception point RP side with respect to the speaker SP1. Then, the coefficient setting unit 5202 sets the tap coefficient using this distance difference Dd. Specifically, the coefficient setting unit 5202 sets the gain value and the delay amount to be set for the virtual sound source ISd according to the distance difference Dd. The coefficient setting unit 5202 sets a smaller gain value as the distance difference Dd is larger, and sets a larger delay amount as the distance difference Dd is larger. Conceptually, as described above, the virtual sound source is being moved, but as the tap coefficient setting process, the coefficient setting unit 5202 may set the tap coefficient according to the distance between the speaker distance and the virtual sound source distance.

[0145] That is, the coefficient setting unit 5202 is located between the sound reception point and the speaker Virtual sound source and only moves . Received It is preferable that the virtual sound source outside the speaker with respect to the sound point does not move, but this also includes the case where the virtual sound source outside moves within a predetermined range. For example, even if this virtual sound source outside moves, it is sufficient if the distance between the virtual sound source outside and the speaker is within a predetermined range. The predetermined range is a range within which the change in the early reflection sound control signal due to the movement does not give the viewer a sense of discomfort. . Relationship If the number setting unit 5202 does not reproduce the virtual sound source closer to the sound reception point than the speaker (S155: NO), the tap coefficient for this virtual sound source is not set.

[0146] The coefficient setting unit 5202 sets the tap coefficients set for each of the speakers SP1 - SP64 to a plurality of LDtaps. More specifically, the coefficient setting unit 5202 sets the tap coefficients for each of the speakers SP1 - SP64 to LDtap 521 based on the virtual sound source positions set in the area Area1. Similarly, the coefficient setting unit 5202 sets the tap coefficients of the virtual sound sources assigned to each of the speakers SP1 - SP64 to LDtaps 522 - 528 respectively, based on the virtual sound source positions set in the plurality of areas Area2 - Area8.

[0147] The plurality of LDtaps 521 - 528 perform gain processing and delay processing on the area - specific sound signals SA1f - SA8f after filter processing according to the set tap coefficients, and output them to the addition processing unit 53. More specifically, as described above, the tap coefficients are set according to the combination of the virtual sound source positions in the plurality of areas and each speaker. Therefore, the plurality of LDtaps 521 - 528 set the tap coefficients based on the virtual sound sources assigned to each speaker for each speaker. The plurality of LDtaps 521 - 528 perform gain processing and delay processing on the area - specific sound signals SA1f - SA8f after filter processing for each speaker. The plurality of LDtaps 521 - 528 output the signals subjected to the gain processing and delay processing for each speaker.

[0148] For example, when virtual sound sources ISa, ISb, ISc, ISd are assigned to the speaker SP1, LDtap 521 performs gain processing and delay processing on the area - specific sound signal SA1f after filter processing according to the tap coefficients (gain values and delay amounts) based on the virtual sound sources ISa, ISb, ISc, ISd. Then, LDtap 521 outputs this signal to the addition processing unit 53 for the speaker SP1. The plurality of LDtaps 52 2 - 528 perform such processing on the virtual sound sources for which the tap coefficients are set.

[0149] The addition processing unit 53 adds the signals after LDtap processing for each of the plurality of speakers SP1 - SP64 output from the plurality of LDtaps 521 - 528, for each of the plurality of speakers SP1 - SP64. The addition processing unit 53 outputs these added signals as the initial reflected sound control signals ER1 - ER64 for each of the plurality of speakers SP1 - SP64 to the adder 80.

[0150] By performing such processing, the initial reflected sound control signal generation unit 50 can generate an initial reflected sound control signal having the following characteristics.

[0151] FIG. 20(A) and FIG. 20(B) are waveform diagrams showing an example of the relationship between the shape of the virtual space and the components of the initial reflected sound control signal realized by LDtap. FIG. 20(A) shows the case where the virtual space shape is large, and FIG. 20(B) shows the case where the virtual space shape is small. Note that FIG. 20(A) and FIG. 20(B) show an example of the components of the initial reflected sound control signal when a plurality of virtual sound sources are set for one speaker.

[0152] When the positional relationship between the reproduction space and the virtual space does not change and the positions of the sound reception point and the speakers do not change, if the virtual space shape is large, the distribution of the virtual sound sources spreads over a wider range than when the virtual space shape is small. Therefore, as shown in FIG. 20(A) and FIG. 20(B), when the virtual space shape is large, each component set by the LDtaps 521 - 528 tends to be smaller, and the distribution range on the time axis also becomes wider.

[0153] Thus, by performing the above-described processing, the initial reflected sound control signal generation unit 50 can set an optimal tap coefficient according to the shape of the virtual space.

[0154] Furthermore, even when the positional relationship between the virtual space and the reproduction space changes, the speaker position changes, or the sound reception point changes, the initial reflected sound control signal generation unit 50 can set an optimal tap coefficient according to these changes, in the same way as when the shape of the virtual space changes.

[0155] At this time, the plurality of sound sources OBJ1-OBJ96 are optimally assigned to the plurality of speakers SP1-SP64 through grouping by the plurality of regions Area1-Area8. And the plurality of virtual sound sources are optimally set for these plurality of speakers SP1-SP64. Therefore, even when there are changes in the relationship between the virtual space and the reproduction space, the change in the sound receiving point RP Change in position , the change in the positions of the plurality of speakers SP1-SP64, and the change in the positions of the sound sources OBJ1-OBJ96, the sound image localization by the early reflection sound can be clarified according to these changes.

[0156] Also, in the above configuration, even when the virtual sound source IS is on the sound receiving point RP side rather than the speaker SP, the early reflection sound control signal generation unit 50 can pseudo-reproduce the component of the early reflection sound control signal by this virtual sound source IS. Therefore, for example, when the number of settings of the virtual sound source for the early reflection sound control signal is small, etc., the early reflection sound control signal generation unit 50 can use a virtual sound source closer to the sound receiving point RP than the speaker SP. At this time, the early reflection sound control signal generation unit 50 relocates the virtual sound source outside the speaker using the distance difference between the virtual sound source IS and the speaker SP as described above. Thereby, the early reflection sound control signal generation unit 50 can suppress the discomfort of the early reflection sound due to moving the position of the virtual sound source.

[0157] In the above configuration, when the virtual sound source IS is at a position closer to the sound receiving point RP than the speaker SP, the early reflection sound control signal generation unit 50 may set this virtual sound source IS at the position of the speaker SP. Thereby, the early reflection sound control signal generation unit 50 can reduce the load of the process of moving the virtual sound source IS.

[0158] Furthermore, in the above configuration, when the virtual sound source IS is at a position closer to the sound receiving point RP than the speaker SP, the early reflection sound control signal generation unit 50 may not use this virtual sound source IS for the generation of the early reflection sound control signal. Thereby, the early reflection sound control signal generation unit 50 does not require the load of the process of moving the virtual sound source IS and can reduce the load of the generation process of the early reflection sound control signal.

[0159] Also, in the above configuration, the early reflection sound control signal generation unit 50 performs tone color adjustment using the FIR filters 511 - 518 while setting the components of the early reflection sound control signal by virtual sound sources. The FIR filters 511 - 518 have the above-described number of taps (for example, 16,000 taps), and have a larger number of taps than the LD taps 521 - 528. Also, the time interval between taps of the FIR filters 511 - 518 (depending on the sampling frequency) is shorter than the time interval between taps of the LD taps 521 - 528 (depending on the arrangement of the virtual sound sources). Therefore, the components of the early reflection sound control signal generated by the FIR filters 511 - 518 are arranged more densely on the time axis than the components of the early reflection sound control signal generated by the LD taps 521 - 528. In other words, the resolution (time resolution) on the time axis of the FIR filters 511 - 518 is higher than that of the LD taps 521 - 528, and the number of components per unit time is increased.

[0160] Then, the early reflection sound control signal generation unit 50 multiplies the processing of the FIR filters 511 - 518 by the LD taps 521 - 528. Therefore, the early reflection sound control signal generation unit 50 can generate early reflection sound control signals ER1 - ER64 with a higher resolution on the time axis and more diverse tone colors. FIG. 21 is a diagram showing an image of the waveform of the early reflection sound control signal generated by the early reflection sound control signal generation unit 50.

[0161] As shown in FIG. 21, the early reflection sound control signal generation unit 50 can generate an early reflection sound control signal with a higher resolution and capable of corresponding to more diverse tone colors while leaving the early reflection sound components by the virtual sound sources. That is, the sound signal processing device 10 can realize an early reflection sound with a tone color according to the user's preference while clearly maintaining the sound image localization by the early reflection sound using the virtual sound sources.

[0162] In addition, due to the high resolution of the FIR filter, for example, when it is short like the pulse sound of a sound source, only the early reflection sound component by LDtap may result in a rough early reflection sound control signal and an unnatural timbre. However, with the above-described configuration and processing, the sound signal processing apparatus 10 can suppress the roughness of such early reflection sound and the unnaturalness of the timbre.

[0163] Also, in the above-described configuration, the early reflection sound control signal generation unit 50 sets the Responsible region of the virtual sound source IS for each speaker SP, and does not assign the virtual sound source IS outside this region to this speaker SP. Thereby, the early reflection sound control signal generation unit 50 , First can suppress the generation of the early reflection sound component. Therefore, the sound signal processing apparatus 10 can suppress the early reflection sound Excessive and realize a more natural early reflection sound according to the virtual space. Excessive generation of

[0164] [Generation of Reverberation Sound Control Signal] FIG. 22 is a functional block diagram showing an example of the configuration of the reverberation sound control signal generation unit 70. FIG. 23 is a flowchart showing an example of the generation process of the reverberation sound control signal.

[0165] As shown in FIG. 22, the reverberation sound control signal generation unit 70 includes a PEQ 71, an FIR filter circuit 72, Distributor 73, a reverberation sound region setting unit 701, a filter coefficient setting unit 702, a reverberation sound reproduction speaker setting unit 703, and an operation unit 700. The FIR filter circuit 72 includes a plurality of FIR filters 721 - 728.

[0166] The reverberation sound region setting unit 701 sets a plurality of reverberation sound regions Arr1 - Arr8 for the reproduction space. More specifically, the reverberation sound region setting unit 701 sets, for example, the reproduction space to be divided into a plurality of reverberation sound regions Arr1 - Arr8 over the entire circumference on the plane with the center point Psr of the reproduction space as a reference (see FIG. 25 described later).

[0167] ​The reverberation sound area setting unit 701 outputs coordinate information indicating a plurality of reverberation sound areas Arr1-Arr8 to the filter coefficient setting unit 702 and the reverberation sound reproduction speaker setting unit 703.

[0168] The filter coefficient setting unit 702 sets filter coefficients for reverberation sounds based on user operations or the like. The filter coefficients for reverberation sounds are set, for example, The different space (virtual space) reproduced in the reproduction space according to the actually measured results of the impulse response in. Note that the filter coefficients for reverberation sounds may be set artificially using the geometric shape of the virtual space, the material of the wall surface, etc. At this time, the filter coefficient setting unit 702 uses the coordinate information for each of the reverberation sound areas Arr1-Arr8 to set filter coefficients for each of the reverberation sound areas Arr1-Arr8.

[0169] The filter coefficient setting unit 702 accepts input of the volume of the virtual space, the surface area of the virtual space, etc. based on user operations or the like. The filter coefficient setting unit 702 sets a fade-in function for the filter coefficients from parameters such as the volume of the virtual space and the surface area of the virtual space.

[0170] More specifically, the filter coefficient setting unit 702 calculates the mean free path ρ using the volume V of the virtual space and the surface area S of the virtual space. The calculation formula for the mean free path ρ is ρ = 4V / S. The mean free path is the average propagation distance in a closed space from when the sound reflects off the wall surface until it reflects again. Proceeds to By dividing the mean free path by the speed of sound c0, the average time required from when the sound reflects off the wall surface until it reflects again can be calculated.

[0171] The filter coefficient setting unit 702 sets the connection timing tc from the mean free path ρ (Fig. 23: S231). Specifically, the filter coefficient setting unit 702 sets the connection timing tc using the mean free path ρ, the speed of sound c0, and the number of reflections n. The calculation formula for the connection timing tc is tc = ρ × n / c0.

[0172] As can be seen from this calculation formula, the connection timing tc corresponds to the average time required for n reflections in the virtual space and corresponds to the time when the reverberation sound starts to transition when reproducing the n-th initial reflection sound. In other words, the connection timing tc corresponds to the timing when the component of the initial reflection sound control signal by the above-described initial reflection sound control signal generation unit 50 disappears.

[0173] By performing such processing, the filter coefficient setting unit 702 can optimally set the connection timing tc between the initial reflection sound and the reverberation sound according to the geometric shape of the virtual space.

[0174] The filter coefficient setting unit 702 sets a fade-in function from the following formula using the connection timing tc (Fig. 23: S232).

[0175]

Equation

[0176] In this formula, t is the elapsed time since the direct sound was generated, and K is set from the following formula.

[0177]

Equation

[0178] In this formula, G REV is the gain value of the reverberation sound at time t = 0 and can be set by the user. For example, generally, the reverberation time is the time required to attenuate to -60 dB, so G REV = -60 dB or the like is appropriate.

[0179] The filter coefficient setting unit 702 sets the filter coefficient for the reverberation sound from the filter coefficient and the fade-in function fin (Fig. 23: S233) and outputs it to the plurality of FIR filters 721-728.

[0180] The reverberation sound generation signal Sr output from the mixer 60 is input to the PEQ 71. The PEQ 71 performs predetermined signal processing on the reverberation sound generation signal Sr and outputs it to a plurality of FIR filters 721-728.

[0181] By performing signal processing by the PEQ 71, the level (signal magnitude), tone color, etc. of the reverberation sound generation signal Sr can be adjusted. For example, the PEQ 71 refers to the volume of the early reflection sound control signal, etc., and adjusts the level (signal magnitude) of the reverberation sound generation signal Sr so that the volume of the early reflection sound and the volume of the reverberation sound are about the same at the above-described connection timing tc. Also, the PEQ 71 can adjust the tone color, etc. according to settings by the user or the like.

[0182] The plurality of FIR filters 721-728 perform filtering on the reverberation sound generation signal Sr using the reverberation sound filter coefficients to generate area-specific reverberation sound control signals REVr1-REVr8. For example, the FIR filter 721 generates the area-specific reverberation sound control signal REVr1 for the area Arr1 by performing a convolution operation on the reverberation sound generation signal Sr using the reverberation sound filter coefficients set for the area Arr1 for the reverberation sound. Similarly, the FIR filters 722-728 generate area-specific reverberation sound control signals REVr2-REVr8 for the areas Arr2-Arr8 by performing convolution operations on the reverberation sound generation signal Sr using the reverberation sound filter coefficients set for the areas Arr2-Arr8 for the reverberation sound, respectively (Figure 23: S234). The plurality of FIR filters 721-728 output the area-specific reverberation sound control signals REVr1-REVr8 Distributor to 73.

[0183] By setting the above-described fade-in function, the reverberation sound control signal has a waveform as shown in Figure 2 4 Figure 24 is a graph showing waveform examples of the direct sound, the early reflection sound control signal, and the reverberation sound control signal. In Figure 24, for convenience, the reverberation sound control signal is illustrated by the envelope of each time component. Also, the vertical axis of Figure 24 is in dB display.

[0184] Figure 24As shown, the reverberation sound control signal is applied from the direct sound output timing to the connection timing tc, and the signal level gradually increases according to the fade-in function. More specifically, the signal level of the reverberation sound control signal is -60 dBFs at the direct sound output timing, gradually increases until the connection timing tc, and becomes 0 dBFs at the connection timing tc. This level is set based on the signal level at the connection timing tc of the early reflection sound control signal.

[0185] In the example of FIG. 24, using the above-mentioned fade-in function, the signal level exponentially increases as it approaches the connection timing tc It is. In other words, The above fade-in function is It has characteristics opposite to those of the attenuation curve of the reverberation sound control signal without performing the fade-in process. Note that the characteristics of the change in the level of the reverberation sound control signal due to the fade-in process are not limited to this, and by appropriately setting the fade-in function, users and the like can set desired characteristics.

[0186] By performing such processing, the reverberation sound control signal generation unit 70 can generate a reverberation sound control signal that accurately reproduces the reverberation sound in the virtual space using the FIR filters 721-728. Also, the reverberation sound control signal gradually increases in signal level in the section where the early reflection sound control signal exists, reaches a peak value corresponding to the signal level of the early reflection sound control signal at the connection timing tc, and then attenuates.

[0187] Thereby, the sound signal processing apparatus 10 reproduces a plurality of LDtaps that reproduce the virtual sound source distribution at a plurality of sound source positions in the virtual space by the reverberation sound by the reverberation sound control signal Generated by The connection between the early reflection sound control signal and the reverberation sound control signal can be made smooth. Therefore, the sound output from the sound signal processing apparatus 10 and heard by the user is a sound with reduced discomfort when connecting from the early reflection sound to the reverberation sound.

[0188] The reverberation sound reproduction speaker setting unit 703 groups the plurality of speakers SP1-SP64 into the reverberation sound regions Arr1-Arr8.

[0189] More specifically, the reverberation sound reproduction speaker setting unit 703 is set to divide the reproduction space into a plurality of reverberation sound regions Arr1-Arr8 over the entire circumference on a plane, for example, with reference to the center point Psr of the reproduction space. The reverberation sound reproduction speaker setting unit 703 groups the plurality of speakers SP1-SP64 with respect to the plurality of reverberation sound regions Arr1-Arr8 using the position coordinates of the plurality of speakers SP1-SP64 and the coordinate information indicating the plurality of reverberation sound regions Arr1-Arr8. This grouping can be realized by the same method as the method of grouping the above-described sound source OBJ.

[0190] FIG. 25 is a diagram showing an example of the region setting for reverberation sound. In FIG. 25, for simplicity of explanation and easy understanding, a plurality of speakers SP1-SP14 are shown. For example, as shown in FIG. 25, the reverberation sound reproduction speaker setting unit 703 detects that there are speakers SP6 and SP7 in the reverberation sound region Arr1, and groups the speakers SP6 and SP7 into the reverberation sound region Arr1. Similarly, the reverberation sound reproduction speaker setting unit 703 also groups the other speakers SP1-SP5, SP8-SP14 into the plurality of reverberation sound regions Arr2-Arr8, respectively.

[0191] The reverberation sound reproduction speaker setting unit 703 outputs the grouping information of the plurality of speakers SP1-SP64 with respect to the plurality of reverberation sound regions Arr2-Arr8 to Distributor 73.

[0192] Distributor 73 uses the grouping information from the reverberation sound reproduction speaker setting unit 703 to assign the reverberation sound control signals REVr1-REVr8 for each region to the plurality of speakers SP1-SP64. Distributor 73 outputs the reverberation sound control signals REVr1-REVr8 for each region as the reverberation sound control signals REV1-REV48 for each of the plurality of speakers SP1-SP64 based on the assignment.

[0193] For example, Distributor73 extracts from the grouping information that the speakers SP6 and SP7 are grouped in the area Arr1. Distributor 73 assigns the reverberation sound control signal REVr1 for the area of the area Arr1 to the speakers SP6 and SP7. Distributor 73 outputs the reverberation sound control signal REVr1 for each area as the reverberation sound control signal REV6 for the speaker SP6 to the speaker SP6. Also, Distributor 73 uses the reverberation sound control signal REVr1 for each area as the reverberation sound control signal REV 7 and outputs it to the speaker SP7.

[0194] Such Distributor By the reverberation sound control signals REVr1 - REVr8 for each area by 73 Allocation process for each area the reverberation sound control signal generation unit 70 can output an optimal reverberation sound control signal to each of the plurality of speakers SP1 - SP64 according to the arrangement of the plurality of speakers SP1 - SP64.

[0195] [Output adjustment] FIG. 26 is a functional block diagram showing an example of the configuration of the output adjustment unit 90. FIG. 27 is a flowchart showing an example of the output adjustment process.

[0196] As shown in FIG. 26, the output adjustment unit 90 includes a gain control unit 91, a delay control unit 92, Gain and delay setting unit 901 , an operation unit 900, and a display unit 909. The gain control unit 91 includes a plurality of gain control units 9101 - 9164 corresponding to the plurality of speakers SP1 - SP64. The delay control unit 92 includes a plurality of delay control units 9201 - 9264 corresponding to the plurality of speakers SP1 - SP64.

[0197] The operation unit 900 receives the setting of the acoustic parameters of the playback space by an operation input from the user (FIG. 27: S321). The acoustic parameters of the playback space are parameters for reproducing a desired sound field in the playback space.

[0198] At this time, the acoustic parameters of the playback space are not the individual gain values and delay amounts of the plurality of speakers SP1 - SP64, but are weight values representing the weighting of sound in a predetermined direction in the playback space and shape values representing the spread of sound in a predetermined direction in the playback space.

[0199] The weight value is composed of a gain value and a delay amount, and includes weight values before and after the playback space, weight values on the left and right of the playback space, and weight values in the vertical direction of the playback space. The shape value is composed of a gain value and a delay amount, and includes a horizontal shape value.

[0200] The display unit 909 includes a GUI. FIG. 28 is a diagram showing an example of the GUI for output adjustment.

[0201] As shown in FIG. 28, the GUI 100A includes a setting display window 111, an output state display window 115, and a plurality of operators 116. The plurality of operators 116 include a knob 1161 and an adjustment value display window 1162.

[0202] The plurality of operators 116 are operators for setting a weight volume for setting a weight value, a shape volume for setting a shape value, and the like. The operator 116 for the weight volume includes operators 116 for setting the left - right weight, the front - back weight, and the up - down weight, each of which includes an operator for setting a gain value and an operator for setting a delay amount. The operator 116 for the shape volume includes an operator for setting the spread, and an operator for setting a gain value and an operator for setting a delay amount.

[0203] The output state display window 115 graphically and schematically displays the spread and sense of localization of the sound realized by the weight value and the shape value set by the plurality of operators 116. Thereby, the user can easily recognize the spread and sense of localization of the sound set by the plurality of operators 116 as an image.

[0204] The user sets the acoustic parameters (weight value and delay amount) that the user wants to reproduce using the GUI 100A of the display unit 909. The operation unit 900 receives the settings using the GUI 100A. The operation unit 900 outputs this setting content (each weight value and each delay amount of the acoustic parameters) to Gain and delay setting unit 901.

[0205] Gain and delay setting unit Based on each weight value and each delay amount of the acoustic parameters, 901 sets the gain value and the delay amount for the plurality of speakers SP1 - SP64. More specifically, Gain and delay setting unit 901 performs the following processing.

[0206] Gain and delay setting unit 901 acquires the position coordinates of the plurality of speakers SP1 - SP64 arranged in the reproduction space (S322). The position coordinates are represented, for example, in a coordinate system in which the x - axis is set in the left - right direction of the reproduction space, the y - axis is set in the front - back direction of the reproduction space, and the z - axis is set in the up - down direction.

[0207] Gain and delay setting unit 901 extracts the maximum value and the minimum value of the position coordinates of the plurality of speakers SP1 - SP64 in each axial direction (S323).

[0208] Gain and delay setting unit 901 stores coefficient setting formulas. The coefficient setting formulas include, for example, a coefficient setting formula for weights for setting weighting in a predetermined direction in the reproduction space and a coefficient setting formula for shapes for setting weighting in a predetermined direction in the reproduction space.

[0209] The coefficient setting formula for weights includes a setting formula for the gain value for weights and a setting formula for the delay amount for weights. The coefficient setting formula for shapes includes a setting formula for the gain value for shapes and a setting formula for the delay amount for shapes.

[0210] The coefficient setting formula for weight includes a coefficient setting formula for the front-back direction that sets the weighting in the front-back direction of the playback space, a coefficient setting formula for the left-right direction that sets the weighting in the left-right direction of the playback space, and a coefficient setting formula for the up-down direction that sets the weighting in the up-down direction of the playback space.

[0211] The coefficient setting formula for shape includes a coefficient setting formula for the left-right direction of the playback space.

[0212] The coefficient setting formula for the gain value of weight is, for example, a linear function that combines the gain value of the set weight value, the maximum and minimum values of the extracted position coordinates, and the position coordinates of the speaker (the speaker to be set) for setting the gain value. The gain value is determined by a formula that is proportional to the difference between the position coordinates of the speaker to be set and the minimum value of the position coordinates.

[0213] The coefficient setting formula for the delay amount of weight is, for example, a linear function that combines the delay amount of the set weight value, the maximum and minimum values of the extracted position coordinates, and the position coordinates of the speaker (the speaker to be set) for setting the delay amount. The delay amount is determined by a formula that is proportional to the difference between the position coordinates of the speaker to be set and the minimum value of the position coordinates.

[0214] The coefficient setting formula for the gain value of shape is, for example, a linear function that combines the gain value of the set shape value, the maximum and minimum values of the extracted position coordinates, and the position coordinates of the speaker (the speaker to be set) for setting the gain value. The gain value is determined by a formula that is proportional to the difference between the position coordinates of the speaker to be set and the minimum value of the position coordinates.

[0215] The coefficient setting formula for the delay amount of shape is, for example, a linear function that combines the delay amount of the set shape value, the maximum and minimum values of the extracted position coordinates, and the position coordinates of the speaker (the speaker to be set) for setting the delay amount. The delay amount is determined by a formula that is proportional to the difference between the position coordinates of the speaker to be set and the minimum value of the position coordinates.

[0216] Gain and delay setting unit901 calculates the gain value and delay amount (acoustic parameters), the maximum and minimum values of the extracted position coordinates, and uses the coefficient setting formula to calculate the gain value and delay amount for each speaker to be set (S324).

[0217] By using such processing, Gain and delay setting unit 901 can automatically calculate and set the gain values and delay amounts of the plurality of speakers SP1 - SP64 arranged in the playback space by the coefficient setting formula without manually setting them individually.

[0218] Gain and delay setting unit 901 outputs the gain values set for each of the plurality of speakers SP1 - SP64 to the plurality of gain control units 9101 - 9164. Gain and delay setting unit 901 outputs the delay amounts set for each of the plurality of speakers SP1 - SP64 to the plurality of delay control units 9201 - 9264.

[0219] To each of the plurality of gain control units 9101 - 9164, speaker signals Sat1 - Sat64 corresponding to the plurality of speakers SP1 - SP64 are input from the adder 80.

[0220] The plurality of gain control units 9101 - 9164 control the signal levels of the speaker signals Sat1 - Sat64 using the gain values set for each of them, and output them to the plurality of delay control units 9201 - 9264. For example, the gain control unit 9101 controls the signal level of the speaker signal Sat1 using the gain value set for the gain control unit 9101, and outputs it to the delay control unit 9201. Similarly, the gain control units 9102 - 9164 control the signal levels of the speaker signals Sat2 - Sat64 using the gain values set for the gain control units 9102 - 9164 respectively, and output them to the delay control units 9202 - 9 2 Output them to 9264 respectively.

[0221] The plurality of delay control units 9201 - 9 264 controls the signal levels of the signals input from the plurality of gain control units 9101 - 9164 using the respectively set delay amounts, and outputs them to the plurality of speakers SP1 - SP64. For example, the delay control unit 9201 controls the signal level of the signal input from the gain control unit 9101 using the delay amount set in the delay control unit 9201, and outputs it to the speaker SP1. Similarly, the delay control units 9202 - 9 2 64 controls the signal levels of the signals input from the gain control units 9102 - 9164 using the delay amounts respectively set in the delay control units 9202 - 9 2 64, and outputs them to the speakers SP 2 -SP64 respectively.

[0222] With such a configuration, the sound signal processing apparatus 10 can easily realize a desired sound field corresponding to the set acoustic parameters using the early reflection sound control signal and the reverberation sound control signal, without forcing the user to make complicated settings individually for the plurality of speakers. Thereby, for example, the sound signal processing apparatus 10 can easily realize a sound field that obtains the Haas effect for a predetermined position in the reproduction space.

[0223] (Example of realizing a sound field by output control) FIGS. 29(A) and 29(B) are diagrams showing a setting example when a Localization and spread is provided at the rear of the reproduction space. FIG. 29(A) is a diagram showing an example of setting the gain value and the delay amount, and FIG. 29(B) is a diagram showing an 9 image of the sound weighting according to the setting of FIG. 2(A). In FIGS. 29(A) and 29(B), for simplicity of explanation and easy understanding, the case where 14 speakers SP1 - SP14 are arranged is shown.

[0224] In the modes shown in FIGS. 29(A) and 29(B), as acoustic parameters, for example, the gain value and the delay amount at the rear end are set. Gain and delay setting unit 901 sets the gain value and the delay amount at the front end to values with the opposite signs of the gain value and the delay amount at the rear end. Gain and delay setting unit901 calculates the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14.

[0225] Gain and delay setting unit 901 uses a coefficient setting formula (for gain value setting) for the front - rear direction that sets the gain values at the rear end and the front end, the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14, and the front - rear direction weighting of the reproduction space to calculate the gain values of the 14 speakers SP1 - SP14.

[0226] Also, Gain and delay setting unit 901 uses a coefficient setting formula (for delay amount setting) for the front - rear direction that sets the delay amounts at the rear end and the front end, the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14, and the front - rear direction weighting of the reproduction space to calculate the delay amounts of the 14 speakers SP1 - SP14.

[0227] By this process, as shown in FIG. 29(A), the sound signal processing device 10 can easily and automatically set acoustic parameters such that the gain value and the delay amount are larger for the speakers at the rear of the reproduction space and smaller for the speakers at the front. Thereby, the sound signal processing device 10 can easily realize a sound field (see FIG. 29(B)) where there is an expansion at the rear of the reproduction space and the sound localization occurs.

[0228] In this description, an example in the front - rear direction is shown, but the sound signal processing device 10 can similarly realize a weighted sound field in the left - right direction and the height direction (up - down direction).

[0229] FIG. 30(A) and FIG. 30(B) are diagrams showing setting examples when giving the sound an expansion in the lateral direction of the reproduction space. FIG. 30(A) is a diagram showing an example of the setting of the gain value and the delay amount, and FIG. 30(B) is a diagram representing the image of the sound expansion according to the setting of FIG. 30(A). Note that in FIG. 30(A) and FIG. 30(B), for simplicity of explanation and easy understanding, the case where the 14 speakers SP1 - SP14 are arranged is shown.

[0230] In the aspect shown in FIGS. 30(A) and 30(B), as an acoustic parameter, for example, a value obtained by quantifying the spread of sound (spread setting value) is set. Gain and delay setting unit 901 calculates the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14.

[0231] The gain and delay setting unit 901 is a value obtained by quantifying the spread of sound, Using the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14 and the coefficient setting formula for shaping (for gain value setting), the gain values of the 14 speakers SP1 - SP14 are calculated.

[0232] Also, Gain and delay setting unit 901 calculates the delay amounts of the 14 speakers SP1 - SP14 using the delay amounts at the rear end and the front end, the maximum and minimum values of the position coordinates of the 14 speakers SP1 - SP14, and the coefficient setting formula for shaping (for delay amount setting).

[0233] By this process, as shown in FIG. 30(A), the sound signal processing device 10 can easily and automatically set acoustic parameters such that the gain value and the delay amount are larger for the speakers closer to both ends in the lateral direction of the reproduction space, and smaller for the speakers closer to the center in the lateral direction. Thereby, the sound signal processing device 10 can easily realize a sound field with a spread in the lateral direction of the reproduction space and a localized sound (see FIG. 30(B)).

[0234] Note that by performing the above-described setting of the acoustic parameters, the sound signal processing device 10 can realize not only the weighting in the front - rear direction, the weighting in the left - right direction, and the spread in the lateral direction of the reproduction space, but also the weighting and spread in the height direction (vertical direction) of the reproduction space. For example, FIG. 31 is a diagram showing an image of the spread of sound when providing spread in the height direction.

[0235] The sound signal processing device 10 increases the gain value and the delay amount of the speaker SPU on the ceiling side compared to the gain value and the delay amount of the speakers SPL and SPR close to the floor surface. Thereby, the sound signal processing device 10 can easily realize a sound field with a spread in the ceiling direction of the reproduction space and a localized sound (see FIG. 31).

[0236] Also, in the above configuration, the output adjustment unit 90 outputs the output signals So1 - So64 to a plurality of speakers SP1 - SP64. However, the audio signal processing apparatus may perform binaural processing on the output signals So1 - So64 and then output them.

[0237] FIG. 32 is a functional block diagram showing the configuration of an audio signal processing apparatus with a binaural playback function. As shown in FIG. 32, the audio signal processing apparatus 10A with a binaural playback function is different from the above-described audio signal processing apparatus 10 in that it includes an output adjustment unit 90A, a reverberation processing unit 97, a selection unit 98, and a binaural processing unit 99.

[0238] The output adjustment unit 90A generates a plurality of output signals So1 - So64 from the plurality of speaker signals Sat1 - Sat64 output from the adder 80 using the same processing as the above-described output adjustment unit 90.

[0239] The output adjustment unit 90A can select the output target. The selection of the output target is executed, for example, by an operation input from the user using the above-described GUI. More specifically, the GUI displays an operator that can select speaker output and binaural output, and when this operator is operated, the output target is selected.

[0240] When speaker output is selected, the output adjustment unit 90A outputs the plurality of output signals So1 - So64 to the plurality of speakers SP1 - S P64 respectively (the same processing as the output adjustment unit 90). When binaural output is selected, the output adjustment unit 90A outputs the plurality of output signals So1 - So64 to the selection unit 98.

[0241] The reverberation processing unit 97 receives the sound signals S1 - S96 of a plurality of sound sources OBJ1 - OBJ96. The reverberation processing unit 97 adds an early reflection sound control signal and a reverberation sound control signal to the plurality of sound signals S1 - S96 and outputs them to the selection unit 98. The early reflection sound control signal for the plurality of sound signals S1 - S96 is set based on the position coordinates of the plurality of sound sources OBJ1 - OBJ96. The reverberation processing unit 97 outputs a plurality of reverberation-processed sound signals S1' - S96' to the selection unit 98.

[0242] The selection unit 98 receives a plurality of output signals So1 - So64 and a plurality of reverberation-processed sound signals S1' - S96'. The selection unit 98 selects, for example, the plurality of output signals So1 - So64 and the reverberation-processed sound signals S1' - S96' according to an operation input from the user using the above-described GUI. More specifically, the GUI displays an operator that can select between the sound obtained by performing acoustic processing on the sound signal processing device 10A and the sound obtained by performing virtual acoustic processing based on the position coordinates of the sound sources OBJ1 - OBJ96, and when this operator is operated, the output target is selected.

[0243] When the sound obtained by performing acoustic processing on the sound signal processing device 10A is selected, the selection unit 98 selects the plurality of output signals So1 - So64 and outputs them to the binaural processing unit 99. When the sound obtained by performing virtual acoustic processing based on the position coordinates of the sound sources OBJ1 - OBJ96 is selected, the selection unit 98 selects the plurality of reverberation-processed sound signals S1' - S96' and outputs them to the binaural processing unit 99.

[0244] The binaural processing unit 99 performs binaural processing on the input sound signal. More specifically, if a plurality of output signals So1 - So64 are input, the binaural processing unit 99 performs binaural processing on the plurality of output signals So1 - So64. If a plurality of reverberation-processed sound signals S1' - S96' are input, the binaural processing unit 99 performs binaural processing on the plurality of reverberation-processed sound signals S1' - S96'.

[0245] Note that binaural processing uses a head transfer function, the details of which are already known, and a detailed description of binaural processing will be omitted.

[0246] The binaural processing unit 99 outputs two-channel sound signals that have undergone binaural processing.

[0247] As a result, the user can listen to the sound generated by the sound signal processing device 10A and the sound subjected to virtual reverberation processing based on the position coordinates of the sound sources OBJ1 - OBJ96 through binaural reproduction. Therefore, without physically constructing the reproduction space, the user can easily confirm using headphones or the like whether the acoustic processing performed by the sound signal processing device 10A can reproduce the acoustics of the virtual space. The acoustic processing performed by the sound signal processing device 10A includes, for example, the above-mentioned grouping of sound sources, setting of the early reflection sound control signal, setting of the reverberation sound control signal, setting of the output control, and the like. And by listening and comparing in this way, the user can adjust the above-mentioned acoustic processing settings so as to reproduce the acoustics of the virtual space more faithfully.

[0248] Note that binaural reproduction is not limited to headphones and may be performed using stereo speakers or the like.

[0249] The description of this embodiment is illustrative in all respects and not restrictive. The scope of the present invention is indicated not by the above-described embodiments but by the scope of the claims. Further, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

Description of Reference Numerals

[0250] 10, 10A: Sound signal processing device 30: Region setting unit 40: Grouping unit 41: Sound source position detection unit 42: Region determination unit 50: Early reflection sound control signal generation unit 51: FIR filter circuit 52: LDtap circuit 53: Addition processing unit 60: Mixer 70: Reverberation control signal generation unit 71: PEQ 72: FIR filter circuit 73: Distributor 80: Adder 90, 90A: Output adjustment unit 91: Gain control unit 92: Delay control unit 97: Reverberation processing unit 98: Selection unit 99: Binaural processing unit 100, 100A: GUI 400: Matrix mixer 500: Operation unit 501: Timbre setting unit 502: Virtual sound source setting unit 511 - 518: FIR filter 521 - 528: LDtap 700: Operation unit 701: Reverberation sound area setting unit 702: Filter coefficient setting unit 703: Reverberation sound playback speaker setting unit 721 - 728: FIR filter 900: Operation unit 901: Gain and delay setting unit 909: Display unit 5201: Output speaker setting unit 5202: Coefficient setting unit 9101 - 9164: Gain control unit 9201 - 9264: Delay control unit

Claims

1. Acquire the audio signal of the sound source, Perform a first filter process on the acquired audio signal to generate a virtual sound source in a virtual space, and perform a second filter process on the audio signal after the first filter process to adjust the timbre of the virtual sound source, thereby generating an early reflection sound control signal, Or Perform the second filter process on the acquired audio signal, and perform the first filter process on the audio signal after the second filter process to generate the early reflection sound control signal, Output the early reflection sound control signal, A method for processing an audio signal, The first filter process is a process of setting a gain value and a delay amount for the input audio signal by using the geometric shape of the virtual space and the position of the virtual sound source, The second filter process is an FIR filter that performs a convolution operation on the input audio signal, The number of components per unit time generated by the second filter process is greater than the number of components per unit time generated by the first filter process, A method for processing an audio signal.

2. The components of the early reflection sound control signal by the first filter process and the components of the early reflection sound control signal by the second filter process are different components on the time axis, The method for processing an audio signal according to Claim 1.

3. The second filter process can set filter characteristics including at least one of a sampling frequency, a filter length, and a filter coefficient, The method for processing an audio signal according to Claim 1 or Claim 2.

4. The filter characteristics of the second filter process can be set by an external operation input, The method for processing an audio signal according to Claim 3.

5. An audio signal acquisition unit that acquires the audio signal of the sound source, Perform a first filter process on the acquired audio signal to generate a virtual sound source in a virtual space by a first filter processing unit, and perform a second filter process on the audio signal after the first filter process to adjust the timbre of the virtual sound source by a second filter processing unit, thereby generating an early reflection sound control signal, Or Perform the second filter process on the acquired audio signal by the second filter processing unit, and perform the first filter process on the audio signal after the second filter process by the first filter processing unit to generate the early reflection sound control signal, A filter processing unit, An early reflection sound control signal output unit that outputs the early reflection sound control signal, Comprising An audio signal processing device, The first filter process is a process of setting a gain value and a delay amount for an input sound signal by using the geometric shape of the virtual space and the position of the virtual sound source. The second filter process is a FIR filter that performs a convolution operation on an input sound signal. The number of components per unit time generated by the second filter process is larger than the number of components per unit time generated by the first filter process. Sound signal processing device. **Claim 6** The components of the early reflection sound control signal by the first filter process of the first filter processing unit and the components of the early reflection sound control signal by the second filter process of the second filter processing unit are different components on the time axis. The sound signal processing device according to claim 5. **Claim 7** The second filter processing unit can set filter characteristics including at least one of a sampling frequency, a filter length, and a filter coefficient. The sound signal processing device according to claim 5 or claim 6. **Claim 8** It includes an operation unit that receives an operation input of the filter characteristics of the second filter process. The sound signal processing device according to claim 7.

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