Sound signal processing methods, sound signal processing devices and recording media

Abstract

The sound signal processing method and apparatus of the present invention suppress the discomfort of sound connection at the junction of the initial reflection and the reverberation. The sound signal processing method generates an initial reflection control signal using analog calculations corresponding to the geometric shape of a virtual space, generates an reverberation control signal using reflection parameters measured in the virtual space, calculates a connection timing based on the geometric shape to make the volumes of the initial reflection control signal and the reverberation control signal the same, and gradually increases the volume of the reverberation control signal in a manner close to the volume of the connection timing during a period earlier than the connection timing.

Description

TECHNICAL FIELD

[0001] One embodiment of the present application relates to a sound signal processing method and a sound signal processing apparatus that perform a predetermined process on a sound input from a sound source. BACKGROUND

[0002] Techniques for controlling initial reflected sound and reverberant sound in a sound system in a space such as a hall are put into practical use in various ways.

[0003] For example, in an adaptive sound field assist device as shown in Patent Literature 1, both the initial reflected sound and the reverberant sound are calculated by measurement. Moreover, the device simply connects the separately measured initial reflected sound and the reverberant sound.

[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2006-261808

[0005] However, in a case where the initial reflected sound of a virtual space is reproduced by simulation using the geometry of the virtual space or the like, sometimes the connection of the sound at the connection portion of the initial reflected sound and the reverberant sound produces a sense of discomfort. SUMMARY

[0006] Therefore, an object of one embodiment of the present application is to suppress a sense of discomfort of the connection of the sound at the connection portion of the initial reflected sound and the reverberant sound.

[0007] The sound signal processing method generates an initial reflected sound control signal using simulation operation corresponding to the geometry of a virtual space, generates a reverberant sound control signal using a reflected sound parameter measured in the virtual space, calculates a connection timing at which the volume of the initial reflected sound control signal and the volume of the reverberant sound control signal become the same based on the geometry, and gradually increases the volume of the reverberant sound control signal in a manner that the volume approaches the volume of the connection timing during a period earlier than the connection timing.

[0008] EFFECT OF THE INVENTION

[0009] The sound signal processing method can suppress a sense of discomfort of the connection of the sound at the connection portion of the initial reflected sound and the reverberant sound. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a functional block diagram showing the structure of a sound system including a sound signal processing apparatus to which an embodiment of the present application relates.

[0011] Figure 2 is a flowchart of a sound signal processing method to which an embodiment of the present application relates.

[0012] Figure 3is a graph showing a discrete waveform of a sound including a direct sound, an initial reflected sound, and a reverberation sound (a late reverberation sound) in general.

[0013] Figure 4 (A) is a graph showing a concept of grouping of sound sources. Figure 4 (B) is a graph showing a concept of setting of virtual sound sources.

[0014] Figure 5 is a functional block diagram showing one example of a structure of the grouping section 40.

[0015] Figure 6 is a flowchart showing a grouping method of sound sources.

[0016] Figure 7 is a graph showing a concept of grouping of a plurality of sound sources to a plurality of regions.

[0017] Figure 8 (A) is a flowchart showing a grouping method of sound sources using representative points, Figure 8

[0018] (B) is a flowchart showing a grouping method of sound sources using boundaries of regions.

[0019] Figure 9 is a flowchart showing one example of a method of grouping by movement of sound sources.

[0020] Figure 10 is a functional block diagram showing one example of a structure of the initial reflected sound control signal generation section 50.

[0021] Figure 11 is a graph showing one example of a GUI.

[0022] Figure 12 is a flowchart showing one example of a setting process of virtual sound sources.

[0023] Figure 13 (A) is a graph showing a concept of grouping of sound sources, Figure 13 (B) is a graph showing a setting example of each virtual sound source when geometrical shapes are different.

[0024] Figure 14 (A) is a graph showing a concept of grouping of sound sources, Figure 14 (B) and Figure 14 (C) are graphs showing a setting example of virtual sound sources.

[0025] Figure 15 (A) is a graph showing a concept of grouping of sound sources, Figure 15 (B), Figure 15 (C) are graphs showing a setting example of virtual sound sources.

[0026] Figure 16 is a flowchart showing a process of assigning virtual sound sources to speakers.

[0027] Figure 17 (A), Figure 17 (B) is a diagram showing the concept of assigning a virtual sound source to a speaker.

[0028] Figure 18 is a flowchart showing the coefficient setting process of LDtap.

[0029] Figure 19 (A), Figure 19 (B) is a diagram for explaining the concept of coefficient setting.

[0030] Figure 20 (A) shows an example of LDtap coefficients in the case where the virtual space shape is large, Figure 20 (B) shows an example of LDtap coefficients in the case where the virtual space shape is small.

[0031] Figure 21 is a diagram showing the waveform of the initial reflected sound control signal generated by the initial reflected sound control signal generation section 50.

[0032] Figure 22 is a functional block diagram showing one example of the structure of the reverberation sound control signal generation section 70.

[0033] Figure 23 is a flowchart showing one example of the generation process of the reverberation sound control signal.

[0034] Figure 24 is a graph showing the waveform examples of the direct sound, the initial reflected sound control signal, and the reverberation sound control signal.

[0035] Figure 25 is a diagram showing one example of the area setting for reverberation sound.

[0036] Figure 26 is a functional block diagram showing one example of the structure of the output adjustment section 90.

[0037] Figure 27 is a flowchart showing one example of the output adjustment process.

[0038] Figure 28 is a diagram showing one example of the GUI for output adjustment.

[0039] Figure 29 (A), Figure 29 (B) is a diagram showing a setting example in the case where the localization and expansion of sound are performed on the rear side of the playback space.

[0040] Figure 30 (A), Figure 30 (B) is a diagram showing a setting example in the case where the localization and expansion of sound are performed in the lateral direction of the playback space.

[0041] Figure 31 is a graph showing an overview of the spread of sound indicating the spread in the height direction.

[0042] Figure 32 is a functional block diagram showing the structure of a sound signal processing apparatus with a binauralization playback function. DETAILED DESCRIPTION

[0043] Embodiments of the present application relating to a sound signal processing method and a sound signal processing apparatus are described with reference to the drawings. Furthermore, in the following embodiments, first, an overview of the sound signal processing method and the sound signal processing apparatus is described, and then, specific contents of each processing and each structure are described.

[0044] Furthermore, in the present embodiment, a playback space is a space in which a user (a listener) listens to sound (direct sound, initial reflected sound, reverberant sound) from a sound source using a speaker or the like. A virtual space is a space having a sound field (acoustics) different from the playback space, and is a space in which initial reflected sound and reverberant sound obtained through the sound field are reproduced (simulated) in the playback space.

[0045] [Outline structure of sound signal processing apparatus]

[0046] Figure 1 is a functional block diagram showing the structure of an acoustic system including the sound signal processing apparatus relating to the embodiments of the present application.

[0047] As shown in Figure 1 , the sound signal processing apparatus 10 has a region setting section 30, a grouping section 40, an initial reflected sound control signal generation section 50, a mixer 60, a reverberant sound control signal generation section 70, a summer 80, and an output adjustment section 90. The sound signal processing apparatus 10 is realized, for example, by an arithmetic processing apparatus such as an electronic circuit or a computer, which realizes the region setting section 30, the grouping section 40, the initial reflected sound control signal generation section 50, the mixer 60, the reverberant sound control signal generation section 70, the summer 80, and the output adjustment section 90, respectively. The portion constituted by the summer 80 and the output adjustment section 90 corresponds to the "output signal generation section" of the present application.

[0048] The sound signal processing apparatus 10 is connected to a plurality of speakers SP1-SP64. Furthermore, Figure 1 A case in which 64 speakers are used is shown, but the number of speakers is not limited thereto.

[0049] The sound signal processing apparatus 10 is inputted with sound signals S1-S96 of a plurality of sound sources OBJ1- OBJ96. Furthermore, Figure 1 A case in which 96 sound sources are used is shown, but the number of sound sources is not limited thereto.

[0050] The region setting section 30 divides the play space into a plurality of regions and sets information (region information) related to the divided regions. The region information is position coordinates that determine the boundaries of the regions, position coordinates of representative points set in the regions.

[0051] The region setting section 30 outputs the region information of the plurality of regions Area 1 - Area 8 set to the grouping section 40. Further, in the present embodiment, the region setting section 30 sets the regions to eight, but the number of regions is not limited to this. Figure 1

[0052] The grouping section 40 groups the sound sources OBJ 1 - OBJ 96 into the plurality of regions Area 1 - Area 8. The grouping section 40 generates a region-distinguished sound signal SA 1 - SA 8 of each region Area 1 - Area 8 using the sound signals S 1 - S 96 of the sound sources OBJ 1 - OBJ 96 based on the result of the grouping. For example, the grouping section 40 frequency-mixes the sound signals of the plurality of sound sources grouped into the region Area 1 to generate the region-distinguished sound signal SA 1.

[0053] The grouping section 40 outputs the plurality of region-distinguished sound signals SA 1 - SA 8 to the initial reflected sound control signal generation section 50. In addition, the grouping section 40 outputs the sound signals S 1 - S 96 of the sound sources OBJ 1 - OBJ 96 to the frequency mixer 60.

[0054] The initial reflected sound control signal generation section 50 generates the initial reflected sound control signals ER 1 - ER 64 for the plurality of speakers SP 1 - SP 64 respectively from the plurality of region-distinguished sound signals SA 1 - SA 8. The initial reflected sound control signals ER 1 - ER 64 are signals respectively output to the speakers SP 1 - SP 64 in order to simulate the initial reflected sound of the virtual space in the play space. The initial reflected sound control signal generation section 50 outputs the generated initial reflected sound control signals ER 1 - ER 64 to the adder 80.

[0055] The initial reflected sound control signal generation section 50 sets a virtual sound source (virtual sound source) on the play space using the positions of the speakers SP 1 - SP 64 arranged in the play space and the geometry of the virtual space, roughly (the detailed structure and processing will be described later). Further, the specific setting of the virtual sound source will be described later. The initial reflected sound control signal generation section 50 generates the initial reflected sound control signals ER 1 - ER 64 that simulate the initial reflected sound in the virtual space by using the virtual sound source. At this time, the initial reflected sound control signal generation section 50 performs the desired timbre adjustment on the initial reflected sound control signals ER 1 - ER 64.

[0056] ​The mixer 60 is an addition 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 control signal generation section 70.

[0057] The reverberation control signal generation section 70 generates, from the reverberation sound generation signal Sr, reverberation control signals REV1-REV64 for the respective plurality of speakers SP1-SP64. The reverberation control signals REV1-REV64 are signals that are respectively output to the speakers SP1-SP64 in order to simulate the reverberation (back reverberation) of the virtual space in the playback space. The reverberation control signal generation section 70 outputs the generated reverberation control signals REV1-REV64 to the adder 80.

[0058] The reverberation control signal generation section 70 roughly (the detailed structure and processing will be described later) divides the playback space into a plurality of reverberation setting regions, and generates the reverberation control signals for the respective plurality of reverberation setting regions. The reverberation control signal generation section 70 allocates the plurality of speakers SP1-SP64 to the plurality of reverberation setting regions. The reverberation control signal generation section 70 sets, on the basis of the allocation, the reverberation control signals for each of the reverberation setting regions to the plurality of speakers SP1-SP64.

[0059] At this time, the reverberation control signal generation section 70 sets the connection timing of the initial reflection sound and the reverberation sound on the basis of the geometric shape of the playback space. The reverberation control signal generation section 70 gradually increases the level (amplitude) of the reverberation control signal during a period before the connection timing, and gradually decreases the level (amplitude) of the reverberation control signal during a period after the connection timing.

[0060] The adder 80 adds the initial reflection control signals and the reverberation control signals that are respectively generated for the plurality of speakers SP1-SP64 to generate a plurality of speaker signals Sat1-Sat64. For example, the adder 80 adds the initial reflection control signal for the speaker SP1 and the reverberation control signal for the speaker SP1 to generate the speaker signal Sat1. The adder 80 outputs the plurality of speaker signals Sat1-Sat64 to the output adjustment section 90.

[0061] The output adjustment section 90 performs gain control and lag control on the plurality of speaker signals Satl-Sat64 to generate output signals Soi-So64. The output adjustment section 90 outputs the output signals Soi-So64 to the plurality of speakers SP1-SP64. For example, the output adjustment section 90 performs gain control and lag control for the speaker SP1 on the speaker signal Satl to generate the output signal Soi. The output adjustment section 90 outputs the output signal Soi to the speaker SP1.

[0062] In outline (the detailed structure and processing will be described later), the output adjustment section 90 receives input of a sound parameter of a sound space. The sound parameter is, for example, a parameter set for adjustment of expansion of a space in a width direction of a sound space, adjustment of expansion of a space on a rear side from a sound pickup point of a sound space, adjustment of expansion of a space in a ceiling direction of a sound space, and the like. The output adjustment section 90 sets collectively gain values and lag amounts (delay amounts) of the plurality of speaker signals Satl-Sat64 on the basis of position coordinates of the plurality of speakers SP1-SP64 and the sound parameter. The collective setting means that the gain values and the lag amounts of the respective speakers are not set individually for each speaker, but, for example, the gain values and the lag amounts of the respective speakers are set by inputting the position coordinates of the respective speakers to a specific calculation formula common to all the speakers. The output adjustment section 90 performs gain control and lag control on the plurality of speaker signals Satl-Sat64 using the set gain values and lag values.

[0063] [Outline processing of sound signal processing method]

[0064] Figure 2 is a flowchart of a sound signal processing method to which an embodiment of the present application relates. Figure 2 shows a sound signal processing method realized by Figure 1 the sound signal processing apparatus 10. Furthermore, Figure 2 the contents of each processing shown in Figure 1 the above-described

[0065] (grouping of sound sources OBJ1- OBJ96)

[0066] The grouping section 40 groups the plurality of sound sources OBJ1- OBJ96 for the plurality of regions Area1-Area8 respectively (S11).

[0067] (generation of initial reflected sound control signals)

[0068] The initial reflected sound control signal generation section 50 sets a timbre for the initial reflected sound for each group (S12). The initial reflected sound control signal generation section 50 sets a virtual sound source for each group (S13). The initial reflected sound control signal generation section 50 generates an initial reflected sound control signal for each of the plurality of speakers SP1-SP64 using the timbre and the virtual sound source (S14).

[0069] (Generation of reverberation sound control signal)

[0070] The mixer 60 adds the sound signals S1-S96 of the plurality of sound sources OBJ1- OBJ96 (S21). The reverberation sound control signal generation section 70 sets a connection timing of the initial reflected sound and the reverberation sound based on the geometric shape of the play space (S22). The reverberation sound control signal generation section 70 generates a reverberation sound control signal using the set connection timing (S23). The reverberation sound control signal generation section 70 distributes 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 play space (S24).

[0071] (Output processing to plurality of speakers)

[0072] The adder 80 adds the initial reflected 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).

[0073] The output adjustment section 90 generates output signals So1-So64 from the speaker signals Sat1-Sat64 using sound parameters that realize localization of reverberation of the play space, expansion of space (S32). The output adjustment section 90 outputs the output signals So1-So64 to the plurality of speakers SP1-SP64 (S33).

[0074] By using the above-described structure and processing, the sound signal processing apparatus 10 (sound signal processing method) obtains various effects described below.

[0075] (1) The sound signal processing apparatus 10 (sound signal processing method) groups the sound sources for each region obtained by dividing the play space, generates the initial reflected sound, and thereby can realize clear sound image localization and rich expansion of space. At this time, the reverberation sound is constant in the entire play space, and only the initial reflected sound changes depending on the position of the sound source. Therefore, for example, in the case where the position of the sound source has moved, the movement of the sound of the sound source is smoother.

[0076] (2) The sound signal processing apparatus 10 (sound signal processing method) generates the initial reflection sound control signal using the virtual sound source, whereby it is possible to more realistically simulate the initial reflection sound based on the geometry of the virtual space in the playback space.

[0077] (3) The sound signal processing apparatus 10 (sound signal processing method) performs the timbre adjustment of the initial reflection sound control signal, whereby it is possible to eliminate unnaturalness of the timbre of the initial reflection sound simulated by the virtual sound source alone, for example.

[0078] (4) The sound signal processing apparatus 10 (sound signal processing method) sets the connection timing of the initial reflection sound control signal and the reverberation sound control signal in accordance with the geometry of the playback space, whereby it is possible to more smoothly and naturally perform the connection from the initial reflection sound to the reverberation sound.

[0079] (5) The sound signal processing apparatus 10 (sound signal processing method) collectively adjusts the gain value and the lag amount of the speaker signals Satl - Sat64 including the initial reflection sound control signal and the reverberation sound control signal, whereby it is possible to realize the sound field desired by the user in the playback space with easier operation input.

[0080] [Detailed description of each signal processing section and each process]

[0081] Hereinafter, a detailed description of each signal processing section and each process described above will be described. First, with reference to the drawings, the initial reflection sound, the reverberation sound, and the virtual sound source necessary for understanding the invention will be described.

[0082] [Initial reflection sound and reverberation sound]

[0083] Figure 3 is a graph showing a discrete waveform of a sound including a usual direct sound, an initial reflection sound, and a reverberation sound (back reverberation sound). For example, a hall in which a performance or a content playback is performed has a closed space surrounded by a wall. If a sound occurs in this closed space, the direct sound, the initial reflection sound, and the reverberation sound (back reverberation sound) reach a sound receiving point.

[0084] The direct sound is a sound that directly reaches the sound receiving point from a sound occurrence position.

[0085] The initial reflection sound is a sound that reaches the sound receiving point at an earlier timing after a sound occurring at the occurrence position is reflected by a wall, a floor, and a ceiling. Therefore, the initial reflection sound reaches the sound receiving point after the direct sound. In addition, the volume (level) of the initial reflection sound is smaller than that of the direct sound. The above-described reflection number is one reflection sound if it is one time, and n reflection sound if it is n times. The arrival direction and the volume of the initial reflection sound at the sound receiving point are largely affected by the occurrence position of the sound.

[0086] The reverberation sound reaches the sound receiving point after the initial reflected sound. The reverberation sound is a sound that reaches the sound receiving point after a plurality of reflections of a sound occurring at the occurrence position. That is, the reverberation sound is a sound that reaches the sound receiving point after further reflections and attenuation of the reflected sound. Therefore, the volume (level) of the reverberation sound is smaller than the volume (level) of the initial reflected sound. Also, the arrival direction and the volume of the reverberation sound are less affected by the occurrence position of the sound than the initial reflected sound.

[0087] [Virtual sound source]

[0088] Figure 4 (A), Figure 4 (B) is a diagram showing a setting concept of a virtual sound source. Further, in Figure 4 (A), Figure 4 (B), a two-dimensional setting concept of a virtual sound source is shown for easy explanation, but a virtual sound source can be set in the same concept in three dimensions. That is, in an actual playback space, in a case where sound sources are not aligned on one plane but are spatially arranged, a virtual space is set in a three-dimensional manner, a virtual sound source is set in three dimensions.

[0089] A sound source SS and a sound receiving point RP exist in a playback space. Further, Figure 4 (A), Figure 4 (B), the sound source SS shown in is a different meaning from the sound source OBJ of the above-described explanation, and refers to a sound source that occurs a normal sound. In addition, a virtual wall IWL for realizing a sound field of a virtual space is set in the playback space. The virtual wall IWL is obtained according to the geometry of the virtual space.

[0090] The sound source SS and the sound receiving point RP exist within a space surrounded by the virtual wall IWL. The virtual wall IWL has 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 in a manner of sandwiching the sound source SS and the sound receiving point RP in a first direction (vertical direction) of the playback space Figure 4 (A), Figure 4 (B). The virtual wall IWL1 is arranged on a side closer to the sound source SS than the sound receiving point RP, and the virtual wall IWL4 is arranged on a side closer to the sound receiving point RP than the sound source SS. The virtual wall IWL2 and the virtual wall IWL3 are arranged in a manner of sandwiching the sound source SS and the sound receiving point RP in a second direction (horizontal direction) of the playback space Figure 4 (A), Figure 4 (B). The virtual wall IWL2 is arranged on a side closer to the sound source SS than the sound receiving point RP, and the virtual wall IWL3 is arranged on a side closer to the sound receiving point RP than the sound source SS.

[0091] If the virtual walls IWL1, IWL2, IWL3, and IWL4 are walls that actually reflect sound, as shown in Figure 4 (B), sound emitted from the sound source SS reaches the sound receiving point RP after being reflected at the virtual walls IWL1, IWL2, and IWL3. Also, in Figure 4 (B), the reflection from the virtual wall IWL4 is not described, but a reflection is also generated at the virtual wall IWL4, as with the virtual walls IWL1, IWL2, and IWL3.

[0092] However, the virtual walls IWL1, IWL2, IWL3, and IWL4 do not actually exist in the playback space. Therefore, as shown in Figure 4 (A), the sound signal processing apparatus 10 sets the virtual sound sources IS1, IS2, and IS3 as if the reflection of sound at the walls were specular reflection.

[0093] Specifically, the sound signal processing apparatus 10 sets the virtual sound source IS1 at a position that is linearly symmetrical with respect to the sound source SS with the virtual wall IWL1 as a reference line. The sound signal processing apparatus 10 sets the virtual sound source IS2 at a position that is linearly symmetrical with respect to the sound source SS with the virtual wall IWL2 as a reference line. The virtual sound source IS3 is set at a position that is linearly symmetrical with respect to the sound source SS with the virtual wall IWL3 as a reference line. Also, by adjusting the sound power of each virtual sound source IS, it is possible to simulate the energy loss of the reflection at the virtual walls IWL.

[0094] By making the above-described settings, the sound occurring at the virtual sound source IS1 is the same as the sound occurring at the sound source SS and reflected at the virtual wall IWL1. The sound occurring at the virtual sound source IS2 is the same as the sound occurring at the sound source SS and reflected at the virtual wall IWL2. The sound occurring at the virtual sound source IS3 is the same as the sound occurring at the sound source SS and reflected at the virtual wall IWL3. Also, in Figure 4 (A), Figure 4 (B), the virtual sound source for the virtual wall IWL4 is not described, but a virtual sound source can also be set for the virtual wall IWL4, as with the virtual walls IWL1, IWL2, and IWL3.

[0095] The sound signal processing apparatus 10 is able to simulate the initial reflected sound of the virtual space in the playback space, which has no actual walls, by setting the virtual sound sources in the above-described manner.

[0096] [Structure and processing of grouping section 40]

[0097] Figure 4This is a functional block diagram illustrating an example of the structure of the grouping section 40. Figure 4 This is a flowchart representing the grouping method of sound sources.

[0098] like Figure 5 As shown, the grouping unit 40 includes a sound source location detection unit 41, a region determination unit 42, and a matrix mixer 400.

[0099] The sound source location detection unit 41 detects the position coordinates of multiple sound sources OBJ1-OBJ96 in the playback space. Figure 6 (S111). For example, the sound source position detection unit 41 detects the position coordinates of sound sources OBJ1-OBJ96 based on user input. Alternatively, the sound source position detection unit 41 may have a position detection sensor for detecting sound sources OBJ1-OBJ96, and detect the position coordinates of sound sources OBJ1-OBJ96 based on the position detected by the position detection sensor.

[0100] The sound source location detection unit 41 outputs the position coordinates of sound sources OBJ1-OBJ96 to the region determination unit 42.

[0101] The region determination unit 42 uses region information from multiple regions Area1-Area8 from the region setting unit 30 and the position coordinates of sound sources OBJ1-OBJ96 from the sound source position detection unit 41 to group sound sources OBJ1-OBJ96 into multiple regions Area1-Area8. Figure 5 (S112). More specifically, the region determination unit 42 groups regions in the following manner.

[0102] Figure 6 This is a diagram representing the concept of grouping multiple sound sources into multiple regions. Furthermore, in Figure 6 In the image, the top side is the front of the hall that serves as the playback space, and the bottom side is the back of the hall.

[0103] The region setting unit 30 sets a reference point Pso for region segmentation based on the playback space. For example, such as Figure 7 As shown, the zone setting unit 30 sets the center position of the hall where the playback space is to be played at the reference point Pso. Furthermore, the zone setting unit 30 can also use a point (position) set by the user as the reference point. For example, the zone setting unit 30 can use a receiver point or similar point set by the user as the reference point.

[0104] The area setting unit 30 sets eight areas, Area1 to Area8, by dividing the entire perimeter of the plane into eight parts, using the reference point Pso for area division as the center. For example, in Figure 7In this case, the region setting section 30 sets the plurality of regions Area 1, Area 2, Area 3 at positions further to the front side of the hall (play space) than the reference point Pso. In addition, the region setting section 30 sets the region Area 4 at a position to the left from the reference point Pso toward the front side of the hall, and sets the region Area 5 at a position to the right from the reference point Pso toward the front side of the hall. In addition, the region setting section 30 sets the plurality of regions Area 6, Area 7, Area 8 at positions further to the rear side of the hall (play space) than the reference point Pso.

[0105] Further, the setting of the regions is one example, and other settings can also be used as long as the entire play space can be covered by the plurality of regions set. In addition, the description shows the setting of planar regions, but the same can also be applied to spatial regions. For example, the vertical direction range of the region Area 1 is also included in the region Area 1.

[0106] The region setting section 30 sets representative points RP1- RP8 for the plurality of regions Area 1- Area 8, respectively. For example, the region setting section 30 sets the plurality of representative points RP1- RP8 at the center positions of the plurality of regions Area 1- Area 8. Alternatively, in the case of regions that are spread in a radial manner, for example, the region setting section 30 sets the representative points at positions on a straight line that passes through the center of the angle at which the regions are spread in a radial manner and that is a prescribed distance from the reference point Pso. Further, the setting method of the representative points is one example, and for example, one representative point can be set for one region, and other methods can also be used as long as the method can reliably perform the grouping of the sound sources. Figure 7

[0107] The region setting section 30 outputs the region information of the plurality of regions Area 1- Area 8 to the region determination section 42 of the grouping section 40 and the matrix mixer 400. The region information of the plurality of regions Area 1- Area 8 is the position coordinates of the representative points RP1- RP8 of the regions Area 1- Area 8, the coordinate information that indicates the boundary lines of the shapes of the regions Area 1- Area 8, and the like.

[0108] (Method of grouping sound sources to regions using representative points)

[0109] Figure 7 (A) is a flowchart that shows the method of grouping sound sources using representative points.

[0110] ​The region determination section 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 section 42 calculates the distance between the position coordinates of the sound source that is the determination object of the grouping and the position coordinates of the representative points RP1-RP8 (S1122). The region determination section 42 groups the sound source to the region that contains the representative point that is the shortest distance (S1123).

[0111] For example, in the case of the sound source OBJ1 in the example of Figure 7 The region determination section 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 section 42 calculates the distance 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. The region determination section 42 detects the case where the distance between the sound source OBJ1 and the representative point RP1 is shorter than the distance between the sound source OBJ1 and the other representative points RP2-RP8. In other words, the region determination section 42 detects the case where the distance between the sound source OBJ1 and the representative point RP1 is the shortest distance. The region determination section 42 groups the sound source OBJ1 to the region Area1 that is associated with the representative point RP1.

[0112] (Method of grouping sound sources to regions using boundaries of regions)

[0113] Figure 8 (B) is a flowchart showing a grouping method of sound sources using boundaries of regions.

[0114] The region determination section 42 acquires the coordinate information (boundary coordinates) of the boundary lines of the regions Area1-Area8 from the region information of the plurality of regions Area1-Area8 (S1124). The region determination section 42 determines whether the position coordinates of the sound source that is the determination object of the grouping are inside each of the regions Area1-Area8 (S1125). For example, the region determination section 42 uses a crossing number algorithm to determine whether the sound source is inside or outside the region. If the sound source is inside the region (S1125: YES), the region determination section 42 groups the sound source to the region (S1126).

[0115] For example, in the case of the sound source OBJ1 in the example of Figure 7In the example where sound source OBJ1 is involved, the region determination unit 42 detects the position coordinates of sound source OBJ1 and obtains the coordinate information (boundary coordinates) representing the boundary lines of multiple regions Area1 to Area8. Based on the position coordinates of sound source OBJ1 and the boundary coordinates of the multiple regions Area1 to Area8, the region determination unit 42 determines whether sound source OBJ1 is inside or outside of the multiple regions Area1 to Area8. The region determination unit 42 detects the case where sound source OBJ1 is within region Area1. The region determination unit 42 then groups sound source OBJ1 into region Area1.

[0116] The area determination unit 42 groups the multiple input sound sources OBJ1-OBJ96 into multiple areas Area1-Area8. For example, if it is... Figure 8 For example, the region determination unit 42 groups sound sources OBJ1 and OBJ4 to region Area1, sound source OBJ2 to region Area2, and sound source OBJ3 to region Area5.

[0117] The zone determination unit 42 outputs the grouping information to the matrix mixer 400. The grouping information indicates which sound source is grouped into which zone.

[0118] The matrix mixer 400 generates area-specific sound signals SA1-SA8 for multiple areas Area1-Area8 based on grouping information and using sound signals S1-S96 from multiple sound sources OBJ1-OBJ96. For example, if there are multiple sound sources in an area group, the matrix mixer 400 mixes the sound signals from these multiple sound sources to generate an area-specific sound signal for that area. The matrix mixer 400 outputs the area-specific sound signals for each area to the initial reflection control signal generation unit 50. Furthermore, even if there is only one sound source in an area group, the matrix mixer 400 outputs the sound signal of that sound source as the area-specific sound signal for that area to the initial reflection control signal generation unit 50.

[0119] in the case of Figure 7 For example, Area 1 is grouped with sound sources OBJ1 and OBJ4. The matrix mixer 400 mixes the audio signal S1 from sound source OBJ1 and the audio signal S4 from sound source OBJ4 to generate and output the area-specific audio signal SA1 for Area 1. Additionally, Area 2 is grouped with sound source OBJ2. The matrix mixer 400 outputs the audio signal S2 from sound source OBJ2 as the area-specific audio signal SA2 for Area 2. Furthermore, Area 5 is grouped with sound source OBJ3. The matrix mixer 400 outputs the audio signal S3 from sound source OBJ3 as the area-specific audio signal SA5 for Area 5.

[0120] By implementing the above-described structure, process, the sound signal processing apparatus 10 can generate the initial reflected sound control signals for each of the plurality of regions into which the sound space is divided, by grouping the plurality of sound sources. As described above, the sound signal processing apparatus 10 can reproduce the initial reflected sound corresponding to the position of the sound source, and can achieve clear sound image localization and rich spatial expansion.

[0121] Further, in the above-described explanation, the case where the sound source moves is not shown in detail, but in the case where the sound source moves, the grouping section 40 performs Figure 7 the process shown in FIG. 10. Figure 7 FIG. 10 is a flowchart showing one example of a method of grouping by movement of a sound source.

[0122] The sound source position detection section 41 detects movement of the sound source (S104). The sound source position detection section 41 detects movement of the sound source, for example, by operation input from a user. Alternatively, the sound source position detection section 41 continuously detects the position of the sound source by a position detection sensor, thereby detecting movement of the sound source. Then, the region determination section 42 re-groups the sound source after movement (S105). The sound source position detection section 41 detects the position coordinates of the sound source after movement and outputs them to the region determination section 42.

[0123] The region determination section 42 uses the position coordinates of the sound source after movement, and groups into the plurality of regions Area1-Area8 as described above (S105).

[0124] By performing the above-described process, even if the sound source moves, the sound signal processing apparatus 10 can generate the initial reflected sound control signals corresponding to the position of the sound source after movement. As described above, the sound signal processing apparatus 10 can reproduce the change in the initial reflected sound corresponding to the movement of the sound source, and can achieve clear sound image localization and rich spatial expansion corresponding to the movement, even if the sound source moves.

[0125] In addition, when movement of the sound source as described above occurs, the sound signal processing apparatus 10 can perform Crossfade processing on the initial reflected sound control signal before movement and the initial reflected sound control signal after movement. For example, when the sound source moves, the sound signal processing apparatus 10 causes the component of the sound signal of the sound source in the region-divided sound signal including the sound source before movement to gradually decrease. On the other hand, the sound signal processing apparatus 10 causes the component of the sound signal of the sound source in the region-divided sound signal including the sound source after movement to gradually increase.

[0126] By performing the processing as described above, the sound signal processing apparatus 10 can suppress the discontinuous change of the initial reflected sound at the time of movement of the sound source. As described above, the sound signal processing apparatus 10 can make the initial reflected sound change more smoothly in accordance with the movement of the sound source at the time of movement of the sound source.

[0127] In addition, the matrix mixer 400 outputs the sound signals S1-S96 of the plurality of sound sources OBJ1- OBJ96 to the mixer 60. As described above, the mixer 60 adds the sound signals S1-S96 to generate the reverberation sound generation signal Sr and outputs it to the reverberation sound control signal generation section 70. The reverberation sound control signal generation section 70 generates the reverberation sound control signals REV1-REV64 using the reverberation sound generation signal Sr.

[0128] By the processing as described above, the reverberation sound is not affected by the position or movement of the sound source. Therefore, even if the sound source moves, the sound signal processing apparatus 10 can maintain the reverberation sound of the playback space constant and reproduce the movement of the sound source more clearly through the change of the initial reflected sound.

[0129] [Generation of initial reflected sound control signal]

[0130] Figure 9 is a functional block diagram showing one example of the structure of the initial reflected sound control signal generation section 50. Figure 9 is a diagram showing one example of a GUI.

[0131] As shown in Figure 10 , the initial reflected sound control signal generation section 50 has a FIR filter circuit 51, an LD tap circuit 52, an addition processing section 53, a tone color setting section 501, a virtual sound source setting section 502, and an operation section 500. The LD tap circuit 52 is a circuit that performs amplification and delay of an input signal and outputs it. The FIR filter circuit 51 has a plurality of FIR filters 511-518. The LD tap circuit 52 has a plurality of LD taps 521-528, an output speaker setting section 5201, and a coefficient setting section 5202. Furthermore, the order of the FIR filter circuit 51 and the LD tap circuit 52 can be reversed.

[0132] [Adjustment of tone color of initial reflected sound]

[0133] The operation section 500 receives designation information of the tone color to be added to the initial reflected sound from the user and outputs it to the tone color setting section 501. The designation information of the tone color is, for example, information that specifies that the bass range is emphasized, the treble range is emphasized, the volume of the initial reflected sound, the decay characteristic of the initial reflected sound, and the like (information indicating a filter characteristic).

[0134] As a specific example, the operation section 500 receives the designation information of the tone color from the user through a GUI, and outputs it to the tone color setting section 501. Figure 11The GUI 100 (Graphical User Interface) shown receives operations.

[0135] The GUI 100 has a setting display window 111, a plurality of operation pieces 112, a knob 1131, and an adjustment value display window 1132.

[0136] The setting display window 111 displays the shape of the virtual wall IWL of the virtual space set by the plurality of operation pieces 112 and the knob 1131. At this time, the setting display window 111 can display the position of the sound source SS, the position of the speaker SP, the position of the reception point RP, and the coordinate axes of the playback space together with the virtual wall IWL.

[0137] The plurality of operation pieces 112 are associated with samples (various halls, rooms, etc.) of the virtual space set in advance. Furthermore, although not shown, the plurality of operation pieces 112 display indices (e.g., hall names, etc.) that explicitly indicate the samples of the virtual space associated with each of the operation pieces 112.

[0138] The knob 1131 is used for setting the room size of the virtual space. The adjustment value display window 1132 displays the set value of the room size of the virtual space.

[0139] The GUI 100 receives various operations for adjusting the tone color. For example, the GUI 100 has a plurality of operation pieces 112, an operation piece for the bass range, an operation piece for the treble range, an operation piece for adjusting the volume, an operation piece for adjusting the attenuation characteristic, etc., and receives operations through these operation pieces.

[0140] If the user operates the desired operation piece using the GUI 100, the operation section 500 detects the operation, and sets the designation information of the tone color in correspondence with the operations.

[0141] For example, if the operation section 500 receives the selection of the plurality of operation pieces 112, it acquires the designation information of the tone color set in advance in the virtual space associated with the operation piece 112. Furthermore, if the operation section 500 receives the operation through the operation piece for the bass range, the operation piece for the treble range, the operation piece for adjusting the volume, the operation piece for adjusting the attenuation characteristic, etc., it acquires the designation information of the tone color set through these operation pieces.

[0142] Furthermore, although not shown, the GUI 100 can also display the designation information of the tone color using, for example, the filter coefficients of the FIR filters 511-518 described later, the approximate waveform, etc. In this case, if the GUI 100 receives the adjustment of the designation information of the tone color, it can also change the display in correspondence with the adjustment. For example, the GUI 100 can change the display of the waveform in correspondence with the adjustment.

[0143] The tone setting section 501 sets the filter coefficients of the FIR filters 511-518 of the FIR filter circuit 51 based on the designation information of the tone. For example, if the tone setting section 501 receives designation information that emphasizes the low frequency range, the tone setting section 501 sets filter coefficients that emphasize the low frequency range of the FIR filters 511-518 of the FIR filter circuit 51. In addition, if the tone setting section 501 receives designation information that emphasizes the high frequency range, the tone setting section 501 sets filter coefficients that emphasize the high frequency range of the FIR filters 511-518 of the FIR filter circuit 51. The tone setting section 501 outputs the set filter coefficients to the FIR filter circuit 51. Note that the tone setting section 501 can set and adjust the sampling frequency and the filter length as the filter characteristics, in addition to the filter coefficients.

[0144] In addition, the tone setting section 501 sets the gain values of the respective taps of the FIR filters 511-518 of the FIR filter circuit 51 based on the designation information of the tone. The tone setting section 501 outputs the set gain values to the FIR filter circuit 51.

[0145] The plurality of FIR filters 511-518 are filters that correspond to the regionally divided sound signals SA1-SA8, respectively. The regionally divided sound signals SA1-SA8 are input to the FIR filters 511-518. For example, as shown in FIG. 5, the regionally divided sound signal SA1 is input to the FIR filter 511, the regionally divided sound signal SA2 is input to the FIR filter 512, the regionally divided sound signal SA3 is input to the FIR filter 513, and the regionally divided sound signal SA4 is input to the FIR filter 514. The regionally divided sound signal SA5 is input to the FIR filter 515, the regionally divided sound signal SA6 is input to the FIR filter 516, the regionally divided sound signal SA7 is input to the FIR filter 517, and the regionally divided sound signal SA8 is input to the FIR filter 518. Figure 10 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 the number of taps is one example, and can be set based on the resource conditions of the sound signal processing apparatus 10, the accuracy of the tone of the original reflected sound that is intended to be reproduced, and the like.

[0146]

[0147] ​The plurality of FIR filters 511-518 respectively perform filter processing (convolution operation) on the plurality of regionally-distinguished sound signals SA1-SA8 by the filter coefficients and the gain values set by the tone setting section 501. As described above, the plurality of FIR filters 511-518 generate the filter-processed regionally-distinguished sound signals SA1f-SA8f. For example, the FIR filter 511 performs filter processing (convolution operation) on the regionally-distinguished sound signal SA1 by the filter coefficients and the gain values set by the tone setting section 501, and generates the filter-processed regionally-distinguished sound signal SA1f. Similarly, the plurality of FIR filters 512-518 respectively generate the filter-processed regionally-distinguished sound signals SA2f-SA8f from the regionally-distinguished sound signals SA2-SA8.

[0148] The plurality of FIR filters 511-518 outputs the filter-processed regionally-distinguished sound signals SA1f-SA8f to the plurality of LD taps 521-528. For example, the FIR filter 511 outputs the filter-processed regionally-distinguished sound signal SA1f to the LD tap 521. Similarly, the plurality of FIR filters 512-518 outputs the filter-processed regionally-distinguished sound signals SA2f-SA8f to the plurality of LD taps 522-528.

[0149] Further, the specification information of the tone is not limited to the emphasis information of the tonal range, but also includes specification information that sets the waveform of the initial reflected sound to a desired characteristic of the user. By using the specification information of the tone as described above, the sound signal processing apparatus 10 can more diversely realize the initial reflected sound of the tone corresponding to the preference of the user.

[0150] [Virtual sound source setting and LD tap setting]

[0151] The virtual sound source setting section 502 sets a virtual sound source based on the position coordinates of the sound pickup point in the playback space and the geometry of the virtual space.

[0152] Figure 11 is a flowchart showing one example of the setting processing of the virtual sound source. The virtual sound source setting section 502 acquires the position coordinates of the sound pickup point of the playback space (S131). For example, the virtual sound source setting section 502 acquires the position coordinates of the sound pickup point of the playback space by an operation input from the user, detection of the position by a position detection sensor, or the like.

[0153] The virtual sound source setting section 502 acquires the geometry of the virtual space (S132). For example, the virtual sound source setting section 502 acquires the geometry of the virtual space by an operation input from the user or the like. The geometry of the virtual space includes a coordinate group or the like showing the shape of the wall arranged in the virtual space.

[0154] The virtual sound source setting section 502 is connected to the GUI 100. If the user selects a desired operation piece 112 from among the plurality of operation pieces 112, the GUI 100 reads and acquires the geometry of the virtual space associated with the operation piece 112. In addition, if the user adjusts the room size (size of the playback space) using the knob 1131, the GUI 100 acquires the adjusted value of the room size.

[0155] The virtual sound source setting section 502 acquires the position coordinates of the geometry of the virtual space in which the room size is set, on the basis of each setting acquired by the GUI 100 in the above-described manner. In addition, the virtual sound source setting section 502 acquires the position coordinates of the sound source SS, the position coordinates of the sweet spot RP (center of the room (center position of the playback space)). The virtual sound source setting section 502 uses these acquired information, and sets the virtual sound source in the following manner. The virtual sound source setting section 502 makes the coordinate system of the playback space and the coordinate system of the virtual space coincide. The virtual sound source setting section 502 uses the position coordinates of the sweet spot of the playback space and the geometry of the virtual space, and sets the position coordinates of the virtual sound source in the playback space by using the concepts of Figure 10 (A), Figure 12 (B) described above.

[0156] Figure 4 (A), Figure 4 (B) are diagrams showing setting examples of each virtual sound source when the geometry is different. Figure 13 (A) is a virtual wall IWL of a quadrangle, Figure 13 (B) is a virtual wall IWLh of a hexagon.

[0157] As described above, if the geometry of the virtual space is different, the positional relationship between the sound source SSa and the sweet spot RP and the virtual wall IWL, and the positional relationship between the sound source SSa and the sweet spot RP and the virtual wall IWLh are different even if the position coordinates of the sound source SSa and the position coordinates of the sweet spot RP do not change. As described above, in the case of Figure 13 (A), the positions of the virtual sound sources IS1a, IS2a, IS3a set are different from the positions of the virtual sound sources IS1ah, IS2ah, IS3ah set in Figure 13 (B).

[0158] Figure 13 (A), Figure 13 (B), and Figure 14 (C) are diagrams showing setting examples of the virtual sound source. Figure 14 (A), Figure 14 (B), Figure 14 (C) are diagrams showing planar changes of the virtual sound source. Figure 14 (B) shows a change in the position of the virtual sound source with respect to Figure 14(A), the position of the sound source Ssa with respect to the reference point (the sound pickup point RP) is the same, and the size of the virtual space is different. Figure 14 (C) shows a case where the position of the sound source Ssa with respect to the reference point (the sound pickup point RP) is different, and the size of the virtual space is the same. Figure 14 (A), the size of the virtual space is the same, and the positional relationship between the reference point of the virtual space and the reference point (the sound pickup point) of the playback space is changed (a case where the room center of the playback space is changed).

[0159] As is apparent from the comparison between Figure 14 (A) and Figure 14 (B), the size of the virtual space on the playback space (the size of the virtual space in the horizontal direction) is different (the size of the virtual space in the horizontal direction in Figure 14 (A) is recorded by the virtual wall IWL, Figure 14 (B) is recorded by the virtual wall IWLc), and thus the distance and the positional relationship between the sound source Ssa as the origin of the virtual sound source and the virtual wall are different. As described above, in Figure 14 (A), the positions of the virtual sound sources ISla, IS2a, IS3a are different from those in Figure 14 (B).

[0160] In addition, as is apparent from the comparison between Figure 14 (A) and Figure 14 (C), the positional relationship between the reference point of the virtual space and the sound pickup point RP is changed, and thus the position of the virtual sound source on the playback space (the position of the virtual sound source with respect to the sound pickup point RP and the speaker) is moved. As described above, in Figure 14 (A), the positions of the virtual sound sources ISla, IS2a, IS3a are different from those in Figure 14 (C).

[0161] Figure 14 (A), Figure 14 (B), Figure 14 (C) are diagrams showing the setting examples of the virtual sound sources. Figure 14 (A), Figure 14 (B), Figure 14 (C) are diagrams showing the change in the position of the virtual sound source in the vertical direction.

[0162] In Figure 14 (A) and Figure 14 (B), the height of the ceiling is different. That is, Figure 14 (A), the distance (height) of the virtual wall IWL from the virtual wall IWFL of the floor to the virtual wall IWCL of the ceiling and Figure 14The distance (height) of the virtual wall IWL from the virtual wall IWFLL of the floor to the virtual wall IWCLL of the ceiling is different.

[0163] As is clear from the comparison results of Figure 14 (A) and Figure 14 (B), the height of the ceiling is different, and thus the distance, positional relationship between the sound source that is the origin of the virtual sound source and the virtual wall IWCL, IWCLL of the ceiling is different. As described above, in Figure 14 (A), the position of the virtual sound source IS1Ca is set differently from Figure 14 (B).

[0164] In Figure 14 (A) and Figure 14 (C), the shape of the ceiling is different. That is, Figure 14 The shape of the virtual wall IWCL of the ceiling of the virtual wall IWL shown in Figure 14 (C) is different from the shape of the virtual wall IWCLx of the ceiling of the virtual wall IWLx shown in

[0165] As is clear from the comparison results of Figure 14 (A) and Figure 14 (C), the shape of the ceiling is different, and thus the positional relationship between the sound source that is the origin of the virtual sound source and the virtual wall IWCL, IWCLx of the ceiling is different. As described above, in Figure 14 (A), the position of the virtual sound source IS1Ca is set differently from Figure 14 (C).

[0166] As described above, the virtual sound source setting section 502 can optimally set the position of the virtual sound source in the playback space in correspondence with the geometry of the virtual space, the positional relationship between the playback space and the virtual space. Thus, the sound signal processing apparatus 10 can make the sound image of the initial reflected sound be positioned clearly in correspondence with the positional coordinates of the speakers of the playback space, the geometry of the virtual space, the positional relationship between the playback space and the virtual space.

[0167] The virtual sound source setting section 502 outputs the positional coordinates of the virtual sound source set for each of the plurality of areas Area1 to Area8 to the output speaker setting section 5201 of the LD tap circuit 52.

[0168] The output speaker setting section 5201 sets the virtual sound source IS allocated to each speaker on the basis of the positional coordinates of the virtual sound source IS, the positional coordinates of the sound pickup point RP, and the positional coordinates of the plurality of speakers SP1 to SP64. Figure 14 is a flowchart showing the process of allocating the virtual sound source to the speaker.

[0169] The output speaker setting unit 5201 obtains the position coordinates of the virtual sound source from the virtual sound source setting unit 502 (S141). The output speaker setting unit 5201 obtains the position coordinates of the receiving point in the playback space, for example, through operation input from the user (S142). The output speaker setting unit 5201 obtains the position coordinates of multiple speakers SP1-SP64, for example, through operation input from the user (S143).

[0170] The output speaker setting unit 5201 sets the area of ​​responsibility of the virtual sound source of each speaker (S144) according to the positional relationship between the sound receiving point RP of the playback space and the multiple speakers SP1-SP64.

[0171] More specifically, the output speaker setting unit 5201 sets the area of ​​responsibility for the virtual sound source of each speaker in the following manner. Figure 14 (A) Figure 14 (B) is a diagram illustrating the concept of assigning a virtual sound source to a loudspeaker. Figure 14 (A) illustrates the concept of using the allocation of azimuth angle φ. Figure 14 (B) illustrates the concept of using the pitch angle θ for allocation. Furthermore, while the following explanation uses speaker SP1 as an example, the output speaker setting unit 5201 also sets the responsible area for other speakers SP2-SP64 using the same method.

[0172] The output speaker setting unit 5201 uses the position coordinates of the receiver point RP and the speaker SP1 to set the position coordinates of the straight line passing through the receiver point RP and the speaker SP1. Figure 14 (A) is set using the dashed line. For example... Figure 14 As shown in (A), the output speaker setting unit 5201 sets the output speaker relative to the straight line ( Figure 14 (A) The dashed line indicates that the azimuth angle φ extending from the receiver point RP to the speaker SP1 on the plane is set. The azimuth angle φ is the angle in the horizontal direction relative to the straight line passing through the receiver point RP and the speaker SP1. Additionally, as... Figure 15 As shown in (B), the output speaker setting unit 5201 sets the line relative to the above-mentioned line ( Figure 15 (B) The pitch angle θ is set by extending in a vertical direction orthogonal to the plane (the dashed line in B). The pitch angle θ is the angle in the vertical direction (orthogonal to the horizontal direction) relative to the straight line passing through the receiver point RP and the speaker SP1.

[0173] The output speaker setting unit 5201 sets the space that is closer to the speaker SP1 than the boundary (the boundary surface that determines the horizontal region and the boundary surface that determines the vertical region) determined by the azimuth angle φ and the elevation angle θ as the responsible area RGSP1 of the speaker SP1.

[0174] The output speaker setting section 5201 acquires the position coordinates of the plurality of virtual sound sources IS (in this case, the plurality of virtual sound sources ISa-ISg). Figure 15

[0175] The output speaker setting section 5201 determines whether the plurality of virtual sound sources ISa-ISg is within the responsible region RGSP1 using the position coordinates of the plurality of virtual sound sources ISa-ISg and the coordinates representing the responsible region RGSP1. This determination can be achieved by the same method as the grouping of the sound sources to regions described above.

[0176] The output speaker setting section 5201 determines, for example, in the cases shown in A, B, and C, that the plurality of virtual sound sources ISa, ISb, ISc, and ISd is within the responsible region RGSP1, and the plurality of virtual sound sources ISe, ISf, and ISg is outside the responsible region RGSP1, by performing this determination process. Figure 15 A、 Figure 15 B、 Figure 15 C.

[0177] The output speaker setting section 5201 assigns the plurality of virtual sound sources ISa, ISb, ISc, and ISd determined to be within the responsible region RGSP1 to the speaker SP1 (S145).

[0178] The output speaker setting section 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 section 5202. At this time, the output speaker setting section 5201 outputs the position coordinates of the listening 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 section 5202 together with the assignment information.

[0179] Further, the azimuth angle φ is, for example, 60°, and the elevation angle θ is, for example, 45°. These angles of the azimuth angle φ and the elevation angle θ are one example, and can be set or adjusted by an operation input from a user, for example.

[0180] The coefficient setting section 5202 sets the tap coefficients to be given to the LDtaps 521-528 using the distances between the listening point RP and the plurality of speakers SP1-SP64 and the distances between the listening point RP and the virtual sound sources IS. The tap coefficients to be given to the LDtaps 521-528 are the gain values and the delay amounts of the LDtaps 521-528.

[0181] Figure 15 is a flowchart showing the coefficient setting process of the LDtap. Figure 15 (A)、 Figure 15 (B) is a diagram for explaining the concept of the coefficient setting.

[0182] ​The coefficient setting section 5202 calculates the distance between the listening point RP and the plurality of speakers SP1-SP64 (speaker distance) using the position coordinates of the listening point RP and the position coordinates of the plurality of speakers SP1-SP64 (S151).

[0183] The coefficient setting section 5202 calculates the distance between the listening point RP and the plurality of virtual sound sources IS (virtual sound source distance) (S152).

[0184] The coefficient setting section 5202 compares the speaker distance and the virtual sound source distance with respect to the plurality of speakers SP1-SP64 and the plurality of virtual sound sources IS respectively allocated to the speakers SP1-SP64 (S153). For example, if it is the case of (A), the speaker distance and the virtual sound source distance are compared with respect to the speaker SP1 and the plurality of virtual sound sources ISa, ISb, ISc, ISd. Figure 15

[0185] If the speaker distance is equal to or smaller than the virtual sound source distance (S153: YES), the coefficient setting section 5202 sets the tap coefficient directly using the virtual sound source distance (S154).

[0186] For example, in the case shown in (A), the virtual sound source Isa is farther from the listening point RP than the speaker SP1, and the virtual sound source distance Lia between the listening point RP and the virtual sound source Isa is larger than the speaker distance Lsl between the listening point RP and the speaker SP1. Figure 15

[0187] In this case, the coefficient setting section 5202 sets the tap coefficient using the distance Dal between the virtual sound source Isa and the speaker SP1. Specifically, the coefficient setting section 5202 sets the gain value and the delay amount set with respect to the virtual sound source Isa in accordance with the distance Dal. For the coefficient setting section 5202, the larger the distance Dal is, the smaller the gain value is set to be, and the larger the distance Dal is, the larger the delay amount is set to be.

[0188] If the speaker distance is larger than the virtual sound source distance (S153: NO), the coefficient setting section 5202 judges whether or not to play the virtual sound source. In other words, the coefficient setting section 5202 judges whether or not to play the virtual sound source on the listening point side than the speaker (S155).

[0189] ​​If the virtual sound source closer to the listening point than the speaker is played (S155: YES), the coefficient setting section 5202 moves the position of the virtual sound source (S156). More specifically, the coefficient setting section 5202 moves the position of the virtual sound source closer to the listening point than the speaker to a position farther from the listening point than the speaker. At this time, the coefficient setting section 5202 moves the position of the virtual sound source using the difference in distance between the virtual sound source and the speaker. The coefficient setting section 5202 sets the tap coefficient using the position coordinates of the moved virtual sound source (S157).

[0190] For example, in the case shown in (B) in which Figure 15 (B), the virtual sound source ISd is closer to the listening point RP than the speaker SP1, and the virtual sound source distance Lid between the listening point RP and the virtual sound source ISd is smaller than the speaker distance Lsl between the listening point RP and the speaker SP1.

[0191] In this case, the coefficient setting section 5202 moves the virtual sound source ISd using the distance difference Dd between the virtual sound source distance Lid and the speaker distance Lsl. More specifically, the coefficient setting section 5202 moves the virtual sound source ISd to a position on a straight line passing through the listening point RP and the speaker SP1 and on the opposite side of the listening point RP from the speaker SP1 by the distance difference Dd. Also, the coefficient setting section 5202 sets the tap coefficient using the distance difference Dd. Specifically, the coefficient setting section 5202 sets the gain value and the delay amount set with respect to the virtual sound source ISd in accordance with the distance difference Dd. The greater the distance difference Dd, the smaller the gain value is set to be, and the greater the distance difference Dd, the greater the delay amount is set to be, for the coefficient setting section 5202. Furthermore, conceptually, the virtual sound source is moved as described above, but as the setting process of the tap coefficient, the coefficient setting section 5202 can set the tap coefficient in accordance with the distance between the speaker distance and the virtual sound source distance.

[0192] That is, the coefficient setting section 5202 moves only the virtual sound source located between the listening point and the speaker. In this regard, the virtual sound source on the outer side of the listening point than the speaker is preferably not moved, but a case in which the virtual sound source on the outer side is moved within a prescribed range is also included. For example, even if the virtual sound source on the outer side is moved, as long as the distance between the virtual sound source on the outer side and the speaker is within a prescribed range, the prescribed range means a range in which a change in the initial reflected sound control signal due to the movement does not cause discomfort to the audience. If the virtual sound source closer to the listening point than the speaker is not played (S155: NO), the coefficient setting section 5202 does not set the tap coefficient for the virtual sound source.

[0193] The coefficient setting section 5202 sets the tap coefficients set for each of the speakers SP1 to SP64 in the plurality of LD taps. More specifically, the coefficient setting section 5202 sets the tap coefficients in the LD tap 521 for each of the speakers SP1 to SP64 based on the virtual sound source positions set in the area Area 1. Similarly, the coefficient setting section 5202 sets the tap coefficients assigned to the virtual sound sources of each of the speakers SP1 to SP64 in the LD taps 522 to 528 based on the virtual sound source positions set in the plurality of areas Area 2 to Area 8, respectively.

[0194] The plurality of LD taps 521 to 528 apply gain processing and delay processing to the filtered sound signals SAlf to SA8f classified by area and output to the addition processing section 53 in accordance with the set tap coefficients. More specifically, the tap coefficients are set in accordance with the combination of the virtual sound source positions of the plurality of areas and each of the speakers as described above. Therefore, the plurality of LD taps 521 to 528 set the tap coefficients based on the virtual sound sources assigned to each of the speakers for each speaker. The plurality of LD taps 521 to 528 apply gain processing and delay processing to the filtered sound signals SAlf to SA8f classified by area for each speaker. The plurality of LD taps 521 to 528 output the signals on which the gain processing and the delay processing have been performed to each of the speakers.

[0195] For example, in a case where the virtual sound sources ISa, ISb, ISc, and ISd are assigned to the speaker SP1, the LD tap 521 applies gain processing and delay processing to the filtered sound signals SAlf classified by area based on the tap coefficients (gain values and delay amounts) of the virtual sound sources ISa, ISb, ISc, and ISd. Furthermore, the LD tap 521 outputs the signal to the addition processing section 53 as for the speaker SP1. The plurality of LD taps 522 to 528 perform the processing as described above for the virtual sound sources for which the tap coefficients are set.

[0196] The addition processing section 53 adds the signals output from the plurality of LD taps 521 to 528 for each of the plurality of speakers SP1 to SP64 for the plurality of speakers SP1 to SP64, respectively. The addition processing section 53 outputs the signals added as the initial reflection sound control signals ER1 to ER64 for each of the plurality of speakers SP1 to SP64 to the adders 80.

[0197] By performing the processing as described above, the initial reflection sound control signal generation section 50 can generate the initial reflection sound control signals having the following characteristics.

[0198] Figure 15 (A), Figure 15(B) is a waveform chart showing an example of the relationship between the shape of the virtual space and the components of the initial reflected sound control signal implemented by the LD tap. Figure 15 (A) shows a case where the shape of the virtual space is large, Figure 15 (B) shows a case where the shape of the virtual space is small. Further, Figure 15 (A), Figure 15 (B) shows an example of the components of the initial reflected sound control signal when a plurality of virtual sound sources are set for one speaker.

[0199] In a case where the positional relationship between the playback space and the virtual space does not change, the position of the sound pickup point and the position of the speaker do not change, if the shape of the virtual space is large, the distribution of the virtual sound sources extends to a wider range compared to the case where the shape of the virtual space is small. Therefore, as shown in Figure 15 (A), Figure 15 (B), the shape of the virtual space is large, each component set in the LD tap 521-528 easily becomes small, and the distribution range on the time axis also becomes wide.

[0200] As described above, by performing the above processing, the initial reflected sound control signal generation section 50 can set the optimal tap coefficients in response to the shape of the virtual space.

[0201] Also, even if the positional relationship between the virtual space and the playback space changes, the position of the speaker changes, or the sound pickup point changes, the initial reflected sound control signal generation section 50 can set the optimal tap coefficients in response to these changes, as in the case where the shape of the virtual space changes.

[0202] At this time, the plurality of sound sources OBJ1- OBJ96 are optimally distributed to the plurality of speakers SP1-SP64 by grouping based on the plurality of areas Area1-Area8. Also, the plurality of virtual sound sources are optimally set with respect to the above plurality of speakers SP1-SP64. Therefore, for the sound signal processing apparatus 10, even if there are changes in the relationship between the virtual space and the playback space, changes in the position of the sound pickup point RP, changes in the positions of the plurality of speakers SP1-SP64, changes in the positions of the sound sources OBJ1- OBJ96, the sound image localization based on the initial reflected sound can be made clear in response to these changes.

[0203] In addition, in the above-described configuration, even if the virtual sound source IS is located closer to the sound pickup point RP than the speaker SP, the initial reflected sound control signal generation section 50 can approximately reproduce the component of the initial reflected sound control signal based on the virtual sound source IS. Therefore, for example, when the number of the virtual sound sources is small with respect to the initial reflected sound control signal, the initial reflected sound control signal generation section 50 can use the virtual sound source closer to the sound pickup point RP than the speaker SP. At this time, the initial reflected sound control signal generation section 50 reconfigures the virtual sound source outside the speaker using the difference in distance between the virtual sound source IS and the speaker SP as described above. As described above, the initial reflected sound control signal generation section 50 can suppress the discomfort of the initial reflected sound due to the movement of the position of the virtual sound source.

[0204] Further, in the above-described configuration, the initial reflected sound control signal generation section 50 can set the virtual sound source IS at the position of the speaker SP in the case where the virtual sound source IS is located closer to the sound pickup point RP than the speaker SP. As described above, the initial reflected sound control signal generation section 50 can reduce the load of the process of moving the virtual sound source IS.

[0205] Further, in the above-described configuration, the initial reflected sound control signal generation section 50 can not use the virtual sound source IS for the generation of the initial reflected sound control signal in the case where the virtual sound source IS is located closer to the sound pickup point RP than the speaker SP. As described above, the initial reflected sound control signal generation section 50 can reduce the load of the generation process of the initial reflected sound control signal without the load of the process of moving the virtual sound source IS.

[0206] In addition, in the above-described configuration, the initial reflected sound control signal generation section 50 performs the setting of the component of the initial reflected sound control signal based on the virtual sound source and the tone adjustment using the FIR filters 511 to 518. The FIR filters 511 to 518 have the above-described tap number (for example, 16000 taps) and have a tap number larger than that of the LD taps 521 to 528. In addition, the time interval of the taps of the FIR filters 511 to 518 (dependent on the sampling frequency) is shorter than the time interval between the taps of the LD taps 521 to 528 (dependent on the arrangement of the virtual sound sources). Therefore, the component of the initial reflected sound control signal generated by the FIR filters 511 to 518 is densely arranged on the time axis compared to the component of the initial reflected sound control signal generated by the LD taps 521 to 528. In other words, the resolution on the time axis (temporal resolution) of the FIR filters 511 to 518 is higher than that of the LD taps 521 to 528, and the number of components per unit time increases.

[0207] Further, the initial reflected sound control signal generation section 50 multiplies the processing of the FIR filters 511-518 and the LD taps 521-528. Therefore, the initial reflected sound control signal generation section 50 can generate the initial reflected sound control signals ER1-ER64 of higher resolution on the time axis and more various sound colors. Figure 16 is a graph showing an outline of the waveform of the initial reflected sound control signal generated by the initial reflected sound control signal generation section 50.

[0208] As shown in Figure 17 , the initial reflected sound control signal generation section 50 can generate the initial reflected sound control signal that leaves the initial reflected sound component obtained based on the virtual sound source and can cope with higher resolution and more various sound colors. That is, the sound signal processing apparatus 10 can realize the initial reflected sound that ensures clear localization of the sound image by the initial reflected sound using the virtual sound source and that is in sound colors that match the user's preference.

[0209] Further, the FIR filter has high resolution, and therefore, for example, in the case of a short sound such as a pulse sound of a sound source, the initial reflected sound control signal becomes rough and the sound color can be unnatural, only based on the initial reflected sound component obtained based on the LD tap. However, by the above-described structure and processing, the sound signal processing apparatus 10 can suppress the sound of the initial reflected sound from becoming rough and the sound color from being unnatural.

[0210] Further, in the above-described structure, the initial reflected sound control signal generation section 50 sets the responsible area of the virtual sound source IS for each speaker SP and does not allocate the virtual sound source IS outside the area to the speaker SP. As described above, the initial reflected sound control signal generation section 50 can suppress the excessive generation of the initial reflected sound component. Therefore, the sound signal processing apparatus 10 can suppress the excessive generation of the initial reflected sound and realize more natural initial reflected sound that matches the virtual space.

[0211] [Generation of reverberation sound control signal]

[0212] Figure 17 is a functional block diagram showing one example of the structure of the reverberation sound control signal generation section 70. Figure 17 is a flowchart showing one example of the generation processing of the reverberation sound control signal.

[0213] As shown in Figure 17 , the reverberation sound control signal generation section 70 has a PEQ 71, a FIR filter circuit 72, a distributor 73, a reverberation area setting section 701, a filter coefficient setting section 702, a playback speaker setting section 703 for reverberation, and an operation section 700. The FIR filter circuit 72 has a plurality of FIR filters 721-728.

[0214] The reverberation-use-area setting section 701 sets a plurality of reverberation-use areas Arrl - Arr8 for the playback space. More specifically, the reverberation-use-area setting section 701 sets the playback space in a manner that divides the entire circumferential range on the plane with the center point Psr of the playback space as a reference, for example (refer to FIG. 2 described later). Figure 17

[0215] The reverberation-use-area setting section 701 outputs coordinate information indicating the plurality of reverberation-use areas Arrl - Arr8 to the filter coefficient setting section 702 and the reverberation-use-playback-speaker setting section 703.

[0216] The filter coefficient setting section 702 sets filter coefficients for reverberation by a user's operation or the like. The filter coefficients for reverberation are set by, for example, measured results of impulse responses of different spaces (virtual spaces) reproduced in the playback space. In addition, the filter coefficients for reverberation can also be set approximately using the geometry of the virtual space, the material of the wall surface, or the like. At this time, the filter coefficient setting section 702 sets the filter coefficients for each of the reverberation-use areas Arrl - Arr8 using the coordinate information of each of the reverberation-use areas Arrl - Arr8.

[0217] The filter coefficient setting section 702 receives input of the volume of the virtual space, the surface area of the virtual space, or the like by a user's operation or the like. The filter coefficient setting section 702 sets an fade-in function for the filter coefficients in accordance with parameters such as the volume of the virtual space, the surface area of the virtual space, or the like.

[0218] More specifically, the filter coefficient setting section 702 calculates the mean free path p using the volume V of the virtual space and the surface area S of the virtual space. The calculation formula of the mean free path p is p = 4V / S. The mean free path refers to the average transmission distance of sound traveling from a wall reflection to the next reflection in a closed space. The average time required for sound to reflect off a wall to the next reflection can be calculated by dividing the mean free path by the speed of sound c0.

[0219] The filter coefficient setting section 702 sets the connection timing tc Figure 17 in accordance with the mean free path p (S231). More specifically, the filter coefficient setting section 702 sets the connection timing tc using the mean free path p, the speed of sound c0, and the number of reflections n. The calculation formula of the connection timing tc is tc = p x n / c0.

[0220] ​As can be known from this calculation formula, the connection timing tc corresponds to the average time required for n times of reflection in the virtual space, and in the case where the n times of initial reflection sounds are reproduced, it corresponds to the timing at which the conversion to the reverberation sound is started. In other words, the connection timing tc corresponds to the timing at which the component of the initial reflection sound control signal obtained by the initial reflection sound control signal generation section 50 described above disappears.

[0221] By performing such processing, the filter coefficient setting section 702 can optimally set the connection timing tc of the initial reflection sound and the reverberation sound in correspondence with the geometry of the virtual space.

[0222] The filter coefficient setting section 702 sets the fade-in function fin using the connection timing tc in accordance with the following formula. Figure 17 : S232).

[0223] [Formula 1]

[0224]

[0225] Further, in this formula, t is the elapsed time from the occurrence of the direct sound, and K is set in accordance with the following formula.

[0226] [Formula 2]

[0227]

[0228] Further, in this formula, G REV is the gain value of the reverberation sound at the timing t = 0, and can be set by the user, for example, the normal reverberation time is the time required for the attenuation to -60 dB, and thus can be set as G REV = -60 dB or the like.

[0229] The filter coefficient setting section 702 sets the reverberation sound filter coefficient (Hr(t)) in accordance with the filter coefficient and the fade-in function fin and outputs it to the plurality of FIR filters 721-728. Figure 17 : S233) and outputs it to the plurality of FIR filters 721-728.

[0230] The reverberation sound generation signal Sr output from the mixer 60 is input to the PEQ 71. The PEQ 71 performs prescribed signal processing on the reverberation sound generation signal Sr and outputs it to the plurality of FIR filters 721-728.

[0231] By processing the signal using the PEQ 71, the level (signal magnitude) and timbre of the reverberation generation signal Sr can be adjusted. For example, the PEQ 71 can adjust the level (signal magnitude) of the reverberation generation signal Sr by referring to the volume of the initial reflection control signal, so that the volume of the initial reflection and the reverberation are at the same level during the connection timing tc mentioned above. Furthermore, the PEQ 71 can adjust the timbre and other parameters according to user settings.

[0232] Multiple FIR filters 721-728 filter the reverberation generation signal Sr using reverberation filtering coefficients to generate region-specific reverberation control signals REVr1-REVr8. For example, FIR filter 721 performs a convolution operation on the reverberation generation signal Sr using the reverberation filtering coefficients set for region Arr1, thereby generating region-specific reverberation control signal REVr1 for region Arr1. Similarly, FIR filters 722-728 perform convolution operations on the reverberation generation signal Sr using the reverberation filtering coefficients set for regions Arr2-Arr8, respectively, thereby generating region-specific reverberation control signals REVr2-REVr8 for regions Arr2-Arr8. Figure 17 (S234). Multiple FIR filters 721-728 output reverberation control signals REVr1-REVr8, differentiated by region, to distributor 73.

[0233] By setting the fade-in function described above, the reverb control signal becomes as follows: Figure 17 The waveform shown. Figure 14 This is a graph showing examples of the waveforms of the direct tone, initial reflection tone control signal, and reverberation tone control signal. Furthermore, in Figure 14 In the diagram, for simplicity, the reverberation control signal is illustrated using the envelopes of each time component. Additionally, Figure 14 The vertical axis represents dB.

[0234] like Figure 18 As shown, the reverb control signal level gradually increases with the fade-in function from the output timing of the direct tone to the connection timing tc. More specifically, the reverb control signal level is -60 dBFs at the output timing of the direct tone, gradually increasing until the connection timing tc, where it becomes 0 dBFs. This level is set based on the initial reverb control signal connection timing tc.

[0235] exist Figure 19In the example of FIG. 9, the fade-in function described above is used to exponentially increase the signal level as the connection timing tc is approached. In other words, the fade-in function described above has an opposite characteristic with respect to the decay curve of the reverberation control signal that is not subjected to the fade-in processing. Furthermore, the characteristic of the change in the level of the reverberation control signal obtained through the fade-in processing is not limited thereto, and can be set to a characteristic desired by a user or the like by appropriately setting the fade-in function.

[0236] By performing the processing described above, the reverberation control signal generation section 70 can generate a reverberation control signal that reproduces the reverberation of the virtual space with high precision using the FIR filters 721 to 728. In addition, with respect to the reverberation control signal, the signal level gradually increases in the section where the initial reflection control signal exists, reaches a peak value corresponding to the signal level of the initial reflection control signal at the connection timing tc, and then decays.

[0237] As described above, the sound signal processing apparatus 10 can smooth the connection between the initial reflection control signal generated by the plurality of LD taps and the reverberation control signal that reproduces the virtual sound source distribution at the plurality of sound source positions of the virtual space by the reverberation based on the reverberation control signal. Therefore, the sound heard by the user from the sound signal processing apparatus 10 becomes a sound that suppresses the discomfort at the time of the connection from the initial reflection to the reverberation.

[0238] The reverberation-use playback speaker setting section 703 groups the plurality of speakers SP1 to SP64 into the reverberation-use areas Arr1 to Arr8.

[0239] More specifically, the reverberation-use playback speaker setting section 703 sets, for example, in a manner that divides the playback space into the plurality of reverberation-use areas Arr1 to Arr8 in the entire circumferential range on the plane with the center point Psr of the playback space as a reference. The reverberation-use playback speaker setting section 703 groups the plurality of speakers SP1 to SP64 with respect to the plurality of reverberation-use areas Arr1 to Arr8 using the position coordinates of the plurality of speakers SP1 to SP64 and the coordinate information that represents the plurality of reverberation-use areas Arr1 to Arr8. This grouping can be achieved by the same method as the method of grouping the sound sources OBJ described above.

[0240] Figure 19 FIG. 10 is a diagram that represents one example of the area setting for the reverberation. In Figure 17 In FIG. 10, the plurality of speakers SP1 to SP14 are illustrated for the purpose of simplifying the description and facilitating understanding. For example, the reverberation-use playback speaker setting section 703 sets the playback space as shown in Figure 19As shown, the presence of the speaker SP6 and the speaker SP7 in the area Arrl for reverberation sound is detected, and the speaker SP6 and the speaker SP7 are grouped to the area Arrl for reverberation sound. Similarly, the reverberation sound playback speaker setting section 703 also groups the other speakers SP1 to SP5 and SP8 to SP14, respectively, to the plurality of areas Arr2 to Arr8 for reverberation sound.

[0241] The reverberation sound playback speaker setting section 703 outputs grouping information of the plurality of speakers SP1 to SP64 with respect to the plurality of areas Arr2 to Arr8 for reverberation sound to the distributor 73.

[0242] The distributor 73 distributes the area-distinguished reverberation sound control signals REVr1 to REVr8 to the plurality of speakers SP1 to SP64 using the grouping information from the reverberation sound playback speaker setting section 703. The distributor 73 outputs the area-distinguished reverberation sound control signals REVr1 to REVr8 as the respective reverberation sound control signals REV1 to REV48 for the plurality of speakers SP1 to SP64 based on the distribution.

[0243] For example, the distributor 73 extracts a case where the speaker SP6 and the speaker SP7 are grouped in the area Arrl according to the grouping information. The distributor 73 distributes the area-distinguished reverberation sound control signal REVr1 of the area Arrl to the speaker SP6 and the speaker SP7. The distributor 73 outputs the area-distinguished reverberation sound control signal REVr1 as the reverberation sound control signal REV6 for the speaker SP6 to the speaker SP6. In addition, the distributor 73 outputs the area-distinguished reverberation sound control signal REVr1 as the reverberation sound control signal REV7 for the speaker SP7 to the speaker SP7.

[0244] By performing the distribution process of the area-distinguished reverberation sound control signals REVr1 to REVr8 for each area by the distributor 73 as described above, the reverberation sound control signal generation section 70 can output the optimal reverberation sound control signal to the plurality of speakers SP1 to SP64 respectively in correspondence with the configuration of the plurality of speakers SP1 to SP64.

[0245] [Output adjustment]

[0246] Figure 19 is a functional block diagram showing one example of the structure of the output adjustment section 90. Figure 20 is a flowchart showing one example of the output adjustment process.

[0247] As Figure 20As shown, the output adjustment unit 90 includes a gain control unit 91, a hysteresis control unit 92, a gain and hysteresis setting unit 901, an operation unit 900, and a display unit 909. The gain control unit 91 has multiple gain control units 9101-9168 corresponding to the multiple speakers SP1-SP64. The hysteresis control unit 92 has multiple hysteresis control units 9201-9264 corresponding to the multiple speakers SP1-SP64.

[0248] The operation unit 900 receives settings for the audio parameters of the playback space via user input. Figure 20 (S321). The acoustic parameters of the playback space are parameters used to reproduce the desired sound field in the playback space.

[0249] At this time, the audio parameters of the playback space are not the gain values ​​or delay values ​​of the multiple speakers SP1-SP64, but rather the weight values ​​representing the weighted distribution of sound in the playback space in a specified direction, and the shape values ​​representing the expansion of sound in the playback space in a specified direction.

[0250] The weight value consists of gain and delay, including weights for the front and back of the playback space, the left and right sides of the playback space, and the up and down directions of the playback space. The shape value consists of gain and delay, including the horizontal shape value.

[0251] Display unit 909 has a GUI. Figure 20 This is a diagram illustrating an example of a GUI used for output adjustment.

[0252] like Figure 20 As shown, the GUI 100A has a setting display window 111, an output status display window 115, and multiple operating components 116. The multiple operating components 116 include a knob 1161 and an adjustment value display window 1162.

[0253] Multiple operating units 116 are operating units for setting weighted volume, shape volume, etc., for setting weight values. The weighted volume operating units 116 include operating units 116 for setting left / right weight, front / back weight, and up / down weight, and operating units 116 for setting gain values ​​and delay amounts. The shape volume operating units 116 include operating units for setting extension, setting gain values, and setting delay amounts.

[0254] The output status display window 115 graphically illustrates the sound expansion and localization achieved by the weight and shape values ​​set by the multiple operating elements 116. Thus, the user can easily recognize the sound expansion and localization set by the multiple operating elements 116 as an image.

[0255] The user sets the sound parameters (weight values and delay amounts) that the user wants to reproduce using the GUI 100A of the display section 909. The operation section 900 receives the setting made using the GUI 100A. The operation section 900 outputs the setting contents (the weight values and the delay amounts of the sound parameters) to the gain and delay setting section 901.

[0256] The gain and delay setting section 901 sets the gain values and the delay amounts for the plurality of speakers SP1-SP64 on the basis of the weight values and the delay amounts of the sound parameters. More specifically, the gain and delay setting section 901 performs the following processing.

[0257] The gain and delay setting section 901 acquires the position coordinates of the plurality of speakers SP1-SP64 disposed in the playback space (S322). The position coordinates are expressed, for example, in a coordinate system that sets the x axis in the left-right direction of the playback space, sets the y axis in the front-rear direction of the playback space, and sets the z axis in the up-down direction.

[0258] The gain and delay setting section 901 extracts the maximum value and the minimum value of the position coordinates of the plurality of speakers SP1-SP64 in each axis direction (S323).

[0259] The gain and delay setting section 901 stores a coefficient setting formula. The coefficient setting formula includes, for example, a coefficient setting formula for a weight that sets the weighting in a prescribed direction in the playback space, and a coefficient setting formula for a shape that sets the weighting in a prescribed direction in the playback space.

[0260] The coefficient setting formula for a weight includes a formula for a gain value of a weight and a formula for a delay amount of a weight. The coefficient setting formula for a shape includes a formula for a gain value of a shape and a formula for a delay amount of a shape.

[0261] The coefficient setting formula for a weight includes a front-rear direction coefficient setting formula that sets the weighting in the front-rear direction of the playback space, a left-right direction coefficient setting formula that sets the weighting in the left-right direction of the playback space, and an up-down direction coefficient setting formula that sets the weighting in the up-down direction of the playback space.

[0262] The coefficient setting formula for a shape includes a left-right direction coefficient setting formula for the playback space.

[0263] The coefficient setting formula for a gain value of a weight is, for example, a linear function obtained by combining the gain value of the set weight value, the maximum value and the minimum value of the extracted position coordinates, and the position coordinates of the speaker (the setting target speaker) that sets the gain value, and is a formula that determines the gain value in proportion to the difference between the position coordinates of the setting target speaker and the minimum value of the position coordinates.

[0264] The coefficient setting formula for the delay amount of the weight is, for example, a linear function obtained by combining the delay amount of the set weight value, the maximum value and the minimum value of the extracted position coordinates, and the position coordinates of the speaker for which the delay amount is set (the speaker of the setting target), and is a formula that determines the delay amount in proportion to the difference between the position coordinates of the speaker of the setting target and the minimum value of the position coordinates.

[0265] The coefficient setting formula for the gain value of the shape is, for example, a linear function obtained by combining the gain value of the set shape value, the maximum value and the minimum value of the extracted position coordinates, and the position coordinates of the speaker for which the gain value is set (the speaker of the setting target), and is a formula that determines the gain value in proportion to the difference between the position coordinates of the speaker of the setting target and the minimum value of the position coordinates.

[0266] The coefficient setting formula for the delay amount of the shape is, for example, a linear function obtained by combining the delay amount of the set shape value, the maximum value and the minimum value of the extracted position coordinates, and the position coordinates of the speaker for which the delay amount is set (the speaker of the setting target), and is a formula that determines the delay amount in proportion to the difference between the position coordinates of the speaker of the setting target and the minimum value of the position coordinates.

[0267] The gain and delay setting section 901 calculates the gain value and the delay amount for each speaker of the setting target, using the set gain value and delay amount (acoustic parameters), the maximum value and the minimum value of the extracted position coordinates, and the coefficient setting formula (S324).

[0268] By using the processing as described above, the gain and delay setting section 901 can automatically calculate and set the gain value and the delay amount of the plurality of speakers SP1-SP64 arranged in the playback space, without manually setting the gain value and the delay amount of the plurality of speakers SP1-SP64 arranged in the playback space individually.

[0269] The gain and delay setting section 901 outputs the gain value set for each of the plurality of speakers SP1-SP64 to the plurality of gain control sections 9101-9164. The gain and delay setting section 901 outputs the delay amount set for each of the plurality of speakers SP1-SP64 to the plurality of delay control sections 9201-9264.

[0270] The plurality of gain control sections 9101-9164 respectively input the speaker signal Sat1-Sat64 corresponding to the plurality of speakers SP1-SP64 from the adder 80.

[0271] The plurality of gain control sections 9101 to 9164 control the signal levels of the speaker-use signals Satl to Sat64 using the gain values set for them, and outputs them to the plurality of lag control sections 9201 to 9264. For example, the gain control section 9101 controls the signal level of the speaker-use signal Satl using the gain value set for the gain control section 9101, and outputs it to the lag control section 9201. Similarly, the gain control sections 9102 to 9164 control the signal levels of the speaker-use signals Sat2 to Sat64 using the gain values set for the gain control sections 9102 to 9164, respectively, and outputs them to the lag control sections 9202 to 9264, respectively.

[0272] The plurality of lag control sections 9201 to 9264 control the signal levels of the signals input from the plurality of gain control sections 9101 to 9164 using the delay amounts set for them, and outputs them to the plurality of speakers SP1 to SP64. For example, the lag control section 9201 controls the signal level of the signal input from the gain control section 9101 using the delay amount set for the lag control section 9201, and outputs it to the speaker SP1. Similarly, the lag control sections 9202 to 9264 control the signal levels of the signals input from the gain control sections 9102 to 9164 using the delay amounts set for the lag control sections 9202 to 9264, respectively, and outputs them to the speakers SP2 to SP64, respectively.

[0273] With the above-described configuration, the sound signal processing apparatus 10 can easily realize the desired sound field corresponding to the set sound parameters using the initial reflected sound control signal and the reverberation sound control signal without the user's expertise in complicated settings for the plurality of speakers, respectively. As described above, for example, the sound signal processing apparatus 10 can easily realize a sound field in which the Haas effect is obtained for a prescribed position within the playback space.

[0274] (Example of Realization of Sound Field Based on Output Control)

[0275] Figure 20 (A), Figure 20 (B) is a diagram showing a setting example in which the localization and the expansion are provided on the rear side of the playback space. Figure 20 (A) is a diagram showing one example of the settings of the gain values and the delay amounts, Figure 21 (B) is a diagram showing the weighting of the sound realized based on Figure 21 (A). Further, in Figure 22 (A), Figure 23 (B), as easily understood in the interest of simplicity of explanation, a case in which 14 speakers SP1 to SP14 are arranged is shown.

[0276] InFigure 22 (A), Figure 25 (B), the gain value and the delay amount of the front side end are set to values of opposite signs to the gain value and the delay amount of the rear side end. The gain and lag setting section 901 calculates the maximum and minimum values of the position coordinates of the 14 speakers SP1-SP14.

[0277] The gain and lag setting section 901 calculates the gain values of the 14 speakers SP1-SP14 using the gain values of the rear side end and the front side end, the maximum and minimum values of the position coordinates of the 14 speakers SP1-SP14, and the coefficient setting formula for the front-rear direction (gain value setting use) set for the weighting of the front-rear direction of the playback space.

[0278] In addition, the gain and lag setting section 901 calculates the delay amounts of the 14 speakers SP1-SP14 using the delay amounts of the rear side end and the front side end, the maximum and minimum values of the position coordinates of the 14 speakers SP1-SP14, and the coefficient setting formula for the front-rear direction (delay amount setting use) set for the weighting of the front-rear direction of the playback space.

[0279] By this processing, the sound signal processing apparatus 10 can automatically and easily set the sound parameters that make the gain value and the delay amount larger for the speakers on the rear side of the playback space and smaller for the speakers on the front side, as shown in Figure 23 (A). Thereby, the sound signal processing apparatus 10 can easily realize a sound field in which the sound is localized on the rear side of the playback space with expansiveness (refer to Figure 23 (B) ).

[0280] Further, in this explanation, an example of the front-rear direction is shown, but the sound signal processing apparatus 10 can also similarly realize a sound field in which weighting is performed with respect to the left-right direction and the height direction (up-down direction).

[0281] Figure 23 (A), Figure 23 (B) is a diagram showing a setting example indicating a case in which the sound has expansiveness in the lateral direction of the playback space. Figure 24 (A) is a diagram showing one example of the setting of the gain value and the delay amount, Figure 24 (B) is a diagram showing an overview of the expansiveness of the sound realized based on the setting of Figure 24 (A). Further, in Figure 24 (A), Figure 24 (B), as easily understood from the simplified explanation, a case in which 14 speakers SP1-SP14 are arranged is shown.

[0282] In Figure 24 (A), Figure 25 (B), as the sound parameter, for example, set the value after the expansion of the sound is valued (expansion set value). The gain and the lag of the setting part 901 calculates the maximum value and the minimum value of the position coordinates of the 14 speakers SP1-SP14.

[0283] The gain and the lag of the setting part 901 uses the value after the expansion of the sound is valued, the maximum value and the minimum value of the position coordinates of the 14 speakers SP1-SP14, and the coefficient setting formula for shape (delay amount setting), calculates the delay amount of the 14 speakers SP1-SP14.

[0284] In addition, the gain and the lag of the setting part 901 uses the delay amount of the rear end and the front end, the maximum value and the minimum value of the position coordinates of the 14 speakers SP1-SP14, and the coefficient setting formula for shape (delay amount setting), calculates the delay amount of the 14 speakers SP1-SP14.

[0285] By this processing, the sound signal processing device 10 can easily set the sound parameter as shown in Figure 25 (A), which makes the gain value and the delay amount larger as the speaker is closer to both ends of the lateral direction of the playback space, and smaller as the speaker is closer to the center of the lateral direction. As described above, the sound signal processing device 10 can easily realize the sound field in which the lateral direction of the playback space has the expansion, and the sound is positioned (refer to Figure 25 (B) ).

[0286] In addition, by performing the above-mentioned setting of the sound parameter, the sound signal processing device 10 can not only realize the weighting in the front-back direction of the playback space, the weighting in the left-right direction, the expansion in the lateral direction, but also realize the weighting, the expansion in the height direction (up-down direction) of the playback space. For example, Figure 26 is a graph showing the overview of the expansion of the sound in the case of having the expansion in the height direction.

[0287] The sound signal processing device 10 makes the gain value and the delay amount of the ceiling side speaker SPU larger than the gain value and the delay amount of the speaker SPL, SPR close to the floor surface. As described above, the sound signal processing device 10 can easily realize the sound field in which the ceiling direction of the playback space has more expansion, and the reverberation is positioned (refer to Figure 27 ).

[0288] In addition, in the above-described configuration, the output adjustment section 90 outputs the output signals Soi-So64 to the plurality of speakers SPi-SP64. However, the sound signal processing apparatus can also perform binaural processing on the output signals Soi-So64 and output them.

[0289] Figure 26 is a functional block diagram showing the configuration of a sound signal processing apparatus with a binaural playback function. As shown in Figure 27 Figure 28 Figure 28 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 29 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 30 Figure 31 Figure 31 Figure 32 Figure 32 the sound signal processing apparatus 10A with a binaural playback function differs from the above-described sound signal processing apparatus 10 in that it has an output adjustment section 90A, a reverberation processing section 97, a selection section 98, and a binaural processing section 99.

[0290] The output adjustment section 90A generates a plurality of output signals Soi-So64 from the plurality of speaker signals Sati-Sat64 output from the adder 80 using the same processing as the above-described output adjustment section 90.

[0291] The output adjustment section 90A is capable of selecting an output target. The selection of the output target is performed, for example, by an operation input from a user using the above-described GUI. More specifically, the GUI displays an operation member capable of selecting speaker output and binaural output, and the output target is selected by operating the operation member.

[0292] In the case where speaker output is selected, the output adjustment section 90A outputs the plurality of output signals Soi-So64 to the plurality of speakers SPi-SP64, respectively (the same processing as the output adjustment section 90). In the case where binaural output is selected, the output adjustment section 90A outputs the plurality of output signals Soi-So64 to the selection section 98.

[0293] The reverberation processing section 97 is input with the plurality of sound signals S1-S96 of the plurality of sound sources OBJ1- OBJ96. The reverberation processing section 97 adds an initial reflection sound control signal and a reverberation sound control signal to the plurality of sound signals S1-S96 and outputs them to the selection section 98. The initial 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 section 97 outputs the plurality of reverberation-processed sound signals S1'-S96' to the selection section 98.

[0294] The selection section 98 is inputted with the plurality of output signals So1-S064 and the plurality of reverberation-processed sound signals S1'-S96'. The selection section 98 selects the plurality of output signals So1-S064 and the reverberation-processed sound signals S1'-S96' by, for example, an operation input from the user using the GUI described above. More specifically, the GUI displays an operation member capable of selecting sound on which the sound signal processing apparatus 10A has performed sound processing and sound on which virtual sound processing based on the position coordinates of the sound sources OBJ1- OBJ96 has been performed, and the output object is selected by operating the operation member.

[0295] In a case where sound on which the sound signal processing apparatus 10A has performed sound processing is selected, the selection section 98 selects the plurality of output signals So1-S064 and outputs to the binauralization processing section 99. In a case where sound on which virtual sound processing based on the position coordinates of the sound sources OBJ1- OBJ96 has been performed is selected, the selection section 98 selects the plurality of reverberation-processed sound signals S1'-S96' and outputs to the binauralization processing section 99.

[0296] The binauralization processing section 99 performs binauralization processing on the inputted sound signals. More specifically, if the plurality of output signals So1-S064 are inputted, the binauralization processing section 99 performs binauralization processing on the plurality of output signals So1-S064. If the plurality of reverberation-processed sound signals S1'-S96' are inputted, the binauralization processing section 99 performs binauralization processing on the plurality of reverberation-processed sound signals S1'-S96'.

[0297] Further, the binauralization processing is processing using a head transfer function, the details of which are known, and detailed description of the binauralization processing is omitted.

[0298] The binauralization processing section 99 outputs the 2-channel sound signals on which binauralization processing has been performed.

[0299] As described above, the user can hear sound generated by the sound signal processing apparatus 10A and sound on which virtual reverberation processing based on the position coordinates of the sound sources OBJ1- OBJ96 has been performed by binauralization playback. Therefore, even without physically constructing a playback space, the user can easily confirm whether or not the sound processing performed by the sound signal processing apparatus 10A can reproduce the sound of a virtual space using headphones or the like. The sound processing performed by the sound signal processing apparatus 10A is, for example, the grouping of sound sources described above, the setting of the initial reflection sound control signal, the setting of the reverberation sound control signal, the setting of the output control, and the like. Furthermore, by performing the audio-visual comparison as described above, the user can adjust the settings of the sound processing described above to reproduce the sound of a virtual space more realistically.

[0300] Further, binaural playback is not limited to headphones, but can also be performed by stereo speakers and the like.

[0301] The description of the embodiments is illustrative in all aspects and is not restrictive. The scope of the present application is not represented by the above-described embodiments but by the claims. Further, the scope of the present application includes all modifications equivalent in meaning and within the scope of the claims.

[0302] Explanation of Reference Signs

[0303] 10, 10A: sound signal processing device

[0304] 30: region setting section

[0305] 40: grouping section

[0306] 41: sound source position detection section

[0307] 42: region determination section

[0308] 50: initial reflected sound control signal generation section

[0309] 51: FIR filter circuit

[0310] 52: LD tap circuit

[0311] 53: addition processing section

[0312] 60: mixer

[0313] 70: reverberation control signal generation section

[0314] 71: PEQ

[0315] 72: FIR filter circuit

[0316] 73: distributor

[0317] 80: adder

[0318] 90, 90A: output adjustment section

[0319] 91: gain control section

[0320] 92: lag control section

[0321] 97: reverberation processing section

[0322] 98: selection section

[0323] 99: binaural processing section

[0324] 100, 100A: GUI

[0325] 400: matrix mixer

[0326] 500: operation section

[0327] 501: tone color setting section

[0328] 502: virtual sound source setting section

[0329] 511-518: FIR filter

[0330] 521-528: LD tap

[0331] 700: operation section

[0332] 701: reverberation sound area setting section

[0333] 702: filter coefficient setting section

[0334] 703: reverberation sound playback speaker setting section

[0335] 721-728: FIR filter

[0336] 900: operation section

[0337] 901: gain and lag setting section

[0338] 909: display section

[0339] 5201: output speaker setting section

[0340] 5202: coefficient setting section

[0341] 9101-9164: gain control section

[0342] 9201-9264: lag control section

Claims

1. A sound signal processing method, wherein sound signals of a plurality of sound sources are input; an initial reflected sound control signal is generated using the sound signals of the plurality of sound sources based on a geometry shape of a virtual space, a reverberation sound control signal is generated using a reverberation sound generation signal generated by mixing the sound signals of the plurality of sound sources and a reflected sound parameter measured in the virtual space, a connection timing at which a volume of an initial reflected sound played by the initial reflected sound control signal and a volume of a reverberation sound played by the reverberation sound control signal become the same based on the geometry shape is calculated, during a period earlier than the connection timing, a level of the reverberation sound control signal is adjusted based on a fade-in function so that the volume of the reverberation sound approaches the volume of the initial reflected sound in a play space at the connection timing, wherein the connection timing tc is calculated using an average free path p, a sound speed c0, and a number of reflections n, and a calculation formula of the connection timing tc is tc = p x n / c0, the average free path p is calculated using a volume V of the virtual space and a surface area S of the virtual space, and a calculation formula of the average free path p is p = 4V / S.

2. The sound signal processing method according to claim 1, wherein the connection timing is calculated based on the volume and the surface area of the virtual space.

3. The sound signal processing method according to claim 1 or 2, wherein the fade-in function is performed using a gain value set for the reverberation sound control signal, and the fade-in function gradually increases the level of the reverberation sound control signal based on an inverse of an exponential decay.

4. The sound signal processing method according to claim 3, wherein filter processing is started from a sound occurrence timing of a sound source that is a source of the reverberation sound control signal, the level of the reverberation sound control signal is gradually increased by correcting the filter processing using an inverse of an exponential decay of the gain value.

5. The sound signal processing method according to claim 1 or 2, wherein for the reverberation sound control signal, during a period later than the connection timing, the level of the reverberation sound control signal is gradually decreased based on a measured value of a reverberation sound of the virtual space.

6. The sound signal processing method according to claim 1 or 2, wherein in a case where sound sources that are sources of the initial reflected sound control signal and the reverberation sound control signal are a plurality of sound sources, the reverberation sound control signal is generated by processing common to the plurality of sound sources.

7. A sound signal processing apparatus that inputs sound signals of a plurality of sound sources, has: an initial reflected sound control signal generation section that generates an initial reflected sound control signal using the sound signals of the plurality of sound sources based on a geometry shape of a virtual space; and a reverberation control signal generation section that generates a reverberation control signal using a signal generated by mixing sound signals of the plurality of sound sources and a reflection sound parameter measured in the virtual space, calculates a connection timing at which a volume of an initial reflection sound played by the initial reflection sound control signal and a volume of a reverberation sound played by the reverberation control signal become the same based on the geometry, and adjusts a level of the reverberation control signal based on a fade-in function during a period earlier than the connection timing so that the volume of the reverberation sound approaches the volume of the initial reflection sound in the playback space at the connection timing, and the connection timing tc is calculated using an average free path p, a sound speed c0, and a number of reflections n, and a calculation formula of the connection timing tc is tc = p x n / c0, the average free path p is calculated using a volume V of the virtual space and a surface area S of the virtual space, and a calculation formula of the average free path p is p = 4V / S.

8. The sound signal processing apparatus according to claim 7, wherein the reverb control signal generation section calculates the connection timing based on a volume and a surface area of the virtual space.

9. The sound signal processing apparatus according to claim 7 or 8, wherein the fade-in function is performed using a gain value set for the reverb control signal, and the fade-in function gradually raises a level of the reverb control signal based on an inverse of exponential decay.

10. The sound signal processing apparatus according to claim 9, wherein the reverb control signal generation section starts a filter process from a generation timing of a sound from a sound source that is a source of the reverb control signal, the level of the reverb control signal is gradually raised by correcting the filter process using an inverse of exponential decay of the gain value.

11. The sound signal processing apparatus according to claim 7 or 8, wherein the reverb control signal generation section gradually lowers the level of the reverb control signal based on a measured value of reverb of the virtual space during a period later than the connection timing.

12. The sound signal processing apparatus according to claim 7 or 8, wherein the reverb control signal generation section, in a case where sound sources that are sources of the initial reflection control signal and the reverb control signal are plural, generates the reverb control signal through a process common to the plural sound sources.

13. A recording medium that is a nonvolatile computer-readable recording medium, recording a program that causes a computer to execute the following processes: inputting sound signals of plural sound sources; generating an initial reflection control signal using the sound signals of the plural sound sources based on a geometric shape of a virtual space, generating a reverb control signal using a reverb generation signal generated by mixing the sound signals of the plural sound sources and a reflection parameter measured in the virtual space, calculating a connection timing at which a volume of an initial reflection played by the initial reflection control signal and a volume of reverb played by the reverb control signal become the same based on the geometric shape, adjusting a level of the reverb control signal based on a fade-in function during a period earlier than the connection timing to cause the volume of the reverb to approach the volume of the initial reflection in a play space at the connection timing, wherein calculating a connection timing tc using an average free path p, a sound speed co, and a reflection number n, the calculation formula of the connection timing tc being tc = p x n / co, calculating the average free path p using a volume V of the virtual space and a surface area S of the virtual space, the calculation formula of the average free path p being p = 4V / S.

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