Sound source object playback device and program

Abstract

To provide a sound source object reproducing apparatus which can calculate a sound pressure in a listening position which is close to a sound source.SOLUTION: A parameter acquisition unit 10 of a sound source object reproducing apparatus 1 acquires parameters of position coordinates, etc., of a sound source object and position coordinates, etc., of sound emitting parts, in modeling processing. A sound pressure calculation unit 11 determines, using the parameters, etc., whether a listening position is located outside or inside of a circumscribed sphere of the sound source object, and calculates, when located outside, a sound pressure p=pV in the listening position using a prior art. The sound pressure calculation unit 11 determines, when the listening position is located inside, whether a listening position is located outside or inside of a circumscribed sphere of each of the sound emitting parts, calculates, when located outside, a sound pressure using the prior art, and sets, when located inside, a fixed value to the sound pressure and adds the sound pressure to determine a sound pressure p=p0 in the listening position.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for modeling an object that serves as a sound source and a collection of such objects, and more particularly to an apparatus and program for reproducing a sound source object using a description method for describing the radiation of sound waves from the model. [Background technology]

[0002] Conventionally, in audio-visual content, a sound source is sometimes treated as an object (sound source object) that exists at a certain position.

[0003] Fig. 12 is a diagram for explaining radiation of sound waves from a sound source object. As shown in Fig. 12, a sound emitted from a sound source is often described as a sound wave radiated from the position of an ambulance, which is the sound source object.

[0004] The simplest way to describe this is to consider a sound source object as a point sound source that radiates spherical waves with omnidirectional characteristics. In this case, the sound waves are radiated uniformly on a sphere with the position of the sound source object represented by the coordinate value of a certain point as the center, and the surface of the sound waves radiated from the position of the sound source object (sound wave front) can be treated as a sphere.

[0005] Taking the position of an object as the base point, the sound pressure at a position equidistant from that position is equal regardless of the direction, and when the distance becomes N times, it is attenuated to 1 / N.

[0006] For example, a sound pressure at a preset reference distance is defined as a parameter of a model of a sound source object. When a listening position is set at a distance N times the reference distance, the sound pressure at the listening position is attenuated to 1 / N, so the sound source object reproducing device presents a sound source signal by attenuating the amplitude of the input signal to 1 / N.

[0007] Another method for calculating the sound pressure at the listening position is to provide a radiation characteristic that changes the sound pressure of the radiated sound waves depending on the direction.

[0008] 13 is a diagram for explaining the emission of sound waves from a sound source object having radiation characteristics. For example, it is assumed that a reference distance is set in advance with the azimuth angle θ and elevation angle φ of a polar coordinate system centered on the position of the sound source object as parameters. Then, the sound pressure at the reference distance for sound waves emitted in the direction of the azimuth angle θ and elevation angle φ is represented by p(θ,φ) and described as a parameter of the model of the sound source object.

[0009] This sound pressure p(θ,φ) represents the attenuation at azimuth angle θ and elevation angle φ relative to the reference distance. When the listening position is N times the reference distance in the direction of azimuth angle θ0 and elevation angle φ0 from the sound source, the sound source object reproduction device presents the sound source signal by multiplying the amplitude of the input signal by p(θ0,φ0) and then attenuating it to 1 / N.

[0010] As shown in Figure 13, sound waves with radiation characteristics are emitted from the sound source object, so the sound pressure p(θ,φ) on a sound wave front at a reference equidistant distance from the sound source object has different values ​​for each direction, as represented by the shades of color on the sound wave front.

[0011] Here, in order to more precisely represent the sound source and the sound field formed by the sound source, the sound source is not regarded as a point sound source but as a wave source having volume.

[0012] Fig. 14 is a diagram explaining a sound source object having a volume. The sound waves from this sound source object are described by the sound pressure distribution on a sphere circumscribing the sound source object, or the sound pressure distribution on a sphere containing the sound source object. By acquiring such a sound pressure distribution on a sphere (sound pressure p(θ,φ)), it is possible to determine the sound field outside the sphere (see, for example, Non-Patent Documents 1 and 2).

[0013] Specifically, the sound pressure distribution on the sphere circumscribing (or including) the sound source object is expanded using spherical harmonic functions. This makes it possible to determine the sound pressure at any listening position using the expansion coefficients (spherical harmonic coefficients) and the distance r0 from the center of the sphere to the listening position (distance r0 is greater than the radius of the sphere).

[0014] Fig. 15 is a diagram for explaining the spherical harmonic function. As shown in Fig. 15, the spherical harmonic function is a function that expresses the shape of a sphere, an ellipsoid, or the like, using a degree n and an order m.

[0015] Fig. 16 is a diagram for explaining the description of radiation based on spherical harmonic expansion. The sound pressure p on the sphere (circumscribed sphere) (Y) circumscribing the sound source object is expressed by the following formula for each angular frequency as a linear sum of the results of multiplying the spherical harmonic functions represented by Y1, Y2, Y3, Y4, etc., which express the shape of the radiation of the sound wave, by weights (expansion coefficients C1, C2, C3, C4, etc.). Note that unlike Figs. 12 to 14, this sound pressure p expresses the magnitude of the sound pressure according to the distance from the sound source object.

number

[0016] In the above formula (1), r is the radius of the circumscribed sphere, θ is the azimuth angle, φ is the elevation angle, ω is the angular frequency, n is the order, m is the rank, and k is the wave number (k=ω / c (c is the speed of sound)). mn is the expansion coefficient, h n is the spherical Hankel function determined by the radius r and the wave number k of the signal, Y n m represents a spherical harmonic function determined by the azimuth angle θ and the elevation angle φ.

[0017] For each angular frequency ω that satisfies the above formula (1), the expansion coefficient C mn (ω) is calculated. Here, the degree n is expressed as an equation up to infinity, but it may be approximated by truncating it at an appropriate degree n.

[0018] In this case, the sound pressure p(r0, θ0, φ0, ω0) of angular frequency ω0 at the listening position (r0, θ0, φ0) outside the circumscribed sphere is expressed by the following equation.

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[0019] The sphere that contains the sound source object is similar to the case of the circumscribing sphere. For simplicity, the case of the circumscribing sphere will be described below. The parameters of the model of the sound source object are the radius r of the circumscribing sphere and the expansion coefficient C for each angular frequency ω. mn (ω), etc. [Prior art documents] [Non-patent literature]

[0020] [Non-Patent Document 1] Shoichi Koyama, "Mathematical problems in sound field reproduction technology", Journal of the Acoustical Society of Japan, Vol.68, No.11(2012), pp.584-589 [Non-Patent Document 2] D. Colton and R. Kress, “Inverse Acoustic and Electromagnetic Scattering Theory”, Springer, 1998 Summary of the Invention [Problem to be solved by the invention]

[0021] As described above, when describing the radiation of sound waves, the description is valid only outside the circumscribing sphere that circumscribes the sound source object. In other words, outside the circumscribing sphere of the sound source object, the sound pressure P(r0, θ0, φ0, ω0) at the listening position with the distance r0 from the center of the circumscribing sphere, the azimuth angle θ0, and the elevation angle φ0 can be correctly calculated by using the above formula (2). Therefore, the sound source object reproducing device can present the sound source signal based on the sound pressure P(r0, θ0, φ0, ω0) of the above formula (2).

[0022] However, inside the circumscribing sphere of the sound source object, that is, when the listening position is close to the sound source, the calculation formula for the sound pressure P(r0, θ0, φ0, ω0) using the above formula (2) does not hold. Therefore, when the listening position is close to the sound source, there is a problem that the sound pressure at the listening position cannot be calculated.

[0023] Therefore, the present invention has been made to solve the above-mentioned problems, and its object is to provide a sound source object playback device and program that can calculate the sound pressure at a listening position even when the listening position is close to the sound source. [Means for solving the problem]

[0024] In order to solve the above problem, the sound source object reproducing device of claim 1 obtains a sound pressure distribution on a sphere circumscribing a sound source object or a sphere including the sound source object, and calculates a sound pressure at a predetermined listening position based on the sound pressure distribution on the sphere, thereby reproducing a signal of the sound source object at the listening position. The sound source object reproducing device obtains a position coordinate a of the sound source object and a radius r of the sphere of the sound source object, and performs spherical harmonic expansion of the sound pressure distribution on the sphere based on a predetermined formula to obtain an expansion coefficient C mn The position coordinate a, the radius r, and the expansion coefficient C mn as parameters of the sound source object, and a plurality of sound generating parts are determined from the sound source object according to an operation of modeling the sound source object by an operator, and for each of the plurality of sound generating parts, position coordinates a of the sound generating part are calculated. l and find the radius r of the sphere that circumscribes the sound-producing part or that contains the sound-producing part. l The sound pressure distribution on the sphere of the sound-generating portion is obtained, and the sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn l The position coordinate a l , said radius r l and the expansion coefficient C mnl a parameter acquisition unit that outputs, as a parameter for each of the plurality of sound generating parts, a parameter acquisition unit that determines whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object output by the parameter acquisition unit, and when it is determined that the listening position is outside the sphere of the sound source object, mn Based on this, the sound pressure p v and when it is determined that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l Based on the above, it is determined whether the listening position is outside or inside the sphere of the sound-producing part, and when it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l and a sound pressure calculation unit which calculates the sound pressure at the listening position from the sound-producing part based on the sound pressure at the listening position, and when it is determined that the listening position is inside the sphere of the sound-producing part, sets a preset fixed value as the sound pressure at the listening position from the sound-producing part, and calculates the sound pressure p0 at the listening position by adding up the sound pressures at the listening position for each of the multiple sound-producing parts.

[0025] A sound source object reproducing device according to claim 2 is the sound source object reproducing device according to claim 1, wherein the sound pressure calculation unit calculates a distance r0 between the sound source object and the listening position based on the position coordinate a and the coordinate of the listening position included in the parameters of the sound source object, and calculates a direction (θ0, φ0) from the sound source object to the listening position; a sound source object position processing unit determines whether the distance r0 calculated by the sound source object position processing unit is greater than the radius r included in the parameters of the sound source object, and if it is determined that the distance r0 is greater than the radius r, determines that the listening position is outside the sphere of the sound source object, and if it is determined that the distance r0 is not greater than the radius r, determines that the listening position is inside the sphere of the sound source object; and if it is determined by the first listening position determination unit that the listening position is outside the sphere of the sound source object, mn Based on the above, the sound pressure p v and when the first listening position determination unit determines that the listening position is inside the sphere of the sound source object, for each of the plurality of sound generating parts, the position coordinate a included in the parameter of the sound generating part is calculated. l and the radius r l Based on the above, it is determined whether the listening position is outside or inside the sphere of the sound-producing part, and when it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l and an inside sound pressure calculation unit that calculates the sound pressure at the listening position from the sound producing part based on the fixed value, and when it is determined that the listening position is inside the sphere of the sound producing part, sets the fixed value to the sound pressure at the listening position from the sound producing part, and calculates the sound pressure p0 at the listening position by adding up the sound pressures at the listening position for each of the multiple sound producing parts.

[0026] The sound source object reproducing device of claim 3 is the sound source object reproducing device of claim 2, wherein the inside sound pressure calculation unit includes a sound part sound pressure calculation unit corresponding to each of the plurality of sound parts, and an adder, and the sound part sound pressure calculation unit calculates the position coordinate a included in the parameter of the sound part. l and based on the coordinates of the listening position, the distance r0 between the sound-producing part and the listening position l and the direction from the sound generating part to the listening position (θ l ,φ0 l ), and the distance r0 l The radius r is included in the parameters of the sound generating portion. l It is determined whether the distance r0 is greater than l is the radius r l If it is determined that the distance r0 is greater than r0, it is determined that the listening position is outside the sphere of the sound-producing portion. l is the radius r l a second listening position determination unit that determines that the listening position is inside the sphere of the sound generation part when the second listening position determination unit determines that the listening position is outside the sphere of the sound generation part, and mn l Based on this, the direction (θ l ,φ0 l ) the first sound pressure p0 at the listening position l and when the second listening position determination unit determines that the listening position is inside the sphere of the sound generating part, the fixed value is calculated based on the direction (θ l ,φ0 l ) at the listening position, p0 l and an inside sound pressure processing unit that sets the first sound pressure p0 l or the second sound pressure p0 set by the inner sound pressure processing unit lThe sound pressure p0 at the listening position is calculated by adding up the sound pressures p0 and p1 for each of the plurality of sound producing portions.

[0027] The sound source object reproducing device of claim 4 is the sound source object reproducing device of claim 1, wherein the parameter acquisition unit acquires the position coordinate a, the radius r and the expansion coefficient C mn as parameters of the sound source object, and in accordance with the modeling operation of the sound source object by the operator, the plurality of sound generating parts are determined from the sound source object, and a plurality of detailed sound generating parts are further determined from the sound generating parts, and the position coordinates a l , said radius r l and the expansion coefficient C mn l and outputting the result as parameters for each of the plurality of sound generation parts and the plurality of detailed sound generation parts, and the sound pressure calculation unit determines whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object, and when it is determined that the listening position is outside the sphere of the sound source object, the expansion coefficient C mn Based on this, the sound pressure p v If it is determined that the listening position is inside the sphere of the sound source object, the position coordinate a l and the radius r l Based on the above, it is determined whether the listening position is outside or inside the sphere of the sound-producing part, and when it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn land when it is determined that the listening position is inside the sphere of the sound producing part, for each of the plurality of detailed sound producing parts further determined from the sound producing part by the parameter acquiring unit, the position coordinate a included in the parameter of the detailed sound producing part is calculated based on the sound pressure of the sound producing part at the listening position. l and the radius r l Based on the above, it is determined whether the listening position is outside or inside the sphere of the detailed sound part, and when it is determined that the listening position is outside the sphere of the detailed sound part, the expansion coefficient C mn l based on the sound pressure at the listening position from the detailed pronunciation part, and when it is determined that the listening position is inside the sphere of the detailed pronunciation part, the fixed value is set to the sound pressure at the listening position from the detailed pronunciation part, and the sound pressures at the listening position in the pronunciation part are obtained by adding up the sound pressures at the listening position for each of the multiple detailed pronunciation parts, and the sound pressure p0 at the listening position is obtained by adding up the sound pressures at the listening position for each of the multiple pronunciation parts.

[0028] The program of claim 5 further provides a computer program for configuring a sound source object reproducing device that obtains a sound pressure distribution on a sphere circumscribing a sound source object or a sphere containing the sound source object, and obtains a sound pressure at a predetermined listening position based on the sound pressure distribution on the sphere, thereby reproducing a signal of the sound source object at the listening position, the computer program comprising: a computer program for obtaining a sound pressure distribution on a sphere circumscribing a sound source object or a sphere containing the sound source object ... and the computer program comprising: a computer program for obtaining a sound pressure distribution on a sphere mn The position coordinate a, the radius r, and the expansion coefficient C mn as parameters of the sound source object, and a plurality of sound generating parts are determined from the sound source object according to an operation of modeling the sound source object by an operator, and for each of the plurality of sound generating parts, position coordinates a of the sound generating part are calculated. l and find the radius r of the sphere that circumscribes the sound-producing part or that contains the sound-producing part.l The sound pressure distribution on the sphere of the sound-generating portion is obtained, and the sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn l The position coordinate a l , said radius r l and the expansion coefficient C mn l a parameter acquisition unit that outputs, as a parameter for each of the plurality of sound generating parts, a parameter acquisition unit that determines whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object output by the parameter acquisition unit, and when it is determined that the listening position is outside the sphere of the sound source object, mn Based on this, the sound pressure p v and when it is determined that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l Based on the above, it is determined whether the listening position is outside or inside the sphere of the sound-producing part, and when it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l and when it is determined that the listening position is inside the sphere of the sound producing part, a preset fixed value is set as the sound pressure at the listening position from the sound producing part, and the sound pressures at the listening position for each of the multiple sound producing parts are added together to function as a sound pressure calculation unit that calculates the sound pressure p0 at the listening position. Effect of the Invention

[0029] As described above, according to the present invention, even if the listening position is close to the sound source, the sound pressure at that position can be calculated and the sound source object can be reproduced at that position. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram for explaining an overview of the present invention. [Diagram 2] 1 is a block diagram showing an example of the configuration of a sound source object reproducing device according to an embodiment of the present invention. [Diagram 3] 4 is a block diagram showing an example of the configuration of a parameter acquisition unit; FIG. [Figure 4] 13 is a flowchart illustrating an example of processing by a parameter acquisition unit. [Diagram 5] 4 is a block diagram showing an example of the configuration of a sound pressure calculation unit; FIG. [Figure 6] 13 is a flowchart illustrating an example of processing by a sound pressure calculation unit. [Figure 7] 4 is a block diagram showing an example of the configuration of an inside sound pressure calculation unit. FIG. [Figure 8] 13 is a flowchart illustrating an example of processing by an inside sound pressure calculation unit. [Figure 9] FIG. 13 is a diagram illustrating an example of a model in which a sound-producing portion is further divided. [Figure 10] 10 is a block diagram showing an example of the configuration of an inside sound pressure calculation section provided in a sound pressure calculation section in the example of FIG. 9. FIG. [Figure 11] FIG. 13 is a diagram illustrating an example of a model in which a plurality of sound source objects are treated as a set. [Figure 12] FIG. 2 is a diagram illustrating radiation of sound waves from a sound source object. [Figure 13] 1A and 1B are diagrams illustrating radiation of sound waves from a sound source object having radiation characteristics. [Figure 14] FIG. 2 is a diagram illustrating a sound source object having volume. [Figure 15] FIG. 2 is a diagram illustrating a spherical harmonic function. [Figure 16] FIG. 1 is a diagram illustrating a description of radiation based on a spherical harmonic expansion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. The present invention switches models hierarchically according to the distance between the listening position and the position of the sound source object. More specifically, the present invention is characterized in that when the listening position is not close to the sound source, the sound pressure at the listening position is calculated using a conventional model of the sound source object, and when the listening position is close to the sound source, the sound pressure at the listening position is calculated using a model in which the sound source object is regarded as a collection of multiple sound-generating parts.

[0032] This makes it possible to calculate the sound pressure at a listening position even when the listening position is close to the sound source, and to reproduce the sound source object at that position, thereby presenting a more immersive and realistic sound image.

[0033] Summary of the Invention 1 is a diagram for explaining an outline of the present invention. A model is assumed in which an ambulance, which is a sound source object OB, is divided into three sound generating parts HA-1, HA-2, and HA-3, which are a tire, an engine, and a siren.

[0034] In the example shown in Figure 1, in the present invention, within the circumscribing sphere (solid circle) of the sound source object OB, the sound source object OB is divided into multiple sound-producing parts HA-1, HA-2, and HA-3 (corresponding to new sound source objects OB-1, OB-2, and OB-3), and each circumscribing sphere (dashed circle) is defined.

[0035] As shown in Figure 1, an ambulance, which is a sound source object OB, has as its sound sources tires, which are sound producing parts HA-1, an engine, which is sound producing part HA-2, and a siren, which is sound producing part HA-3. In this case, the sound waves emitted from each of the sound producing parts HA-1, HA-2, and HA-3 are defined by the circumscribed spheres shown by the dashed lines and the sound pressure distribution on the boundaries.

[0036] When the listening position T1 is outside the circumscribing sphere of the sound source object OB, the sound pressure at the listening position T1 is calculated from the sound pressure distribution on the circumscribing sphere of the sound source object OB by the above-mentioned conventional technology.

[0037] On the other hand, when listening position T2 is inside the circumscribed sphere of sound source object OB, the sound pressure at listening position T2 is calculated by overlapping the sound waves from each of the sound generating parts HA-1, HA-2, and HA-3. In other words, assuming that listening position T2 is in the direction and at the distance from each of the sound generating parts HA-1, HA-2, and HA-3 as indicated by the arrows, the respective sound pressures are calculated, and these are added together to obtain the sound pressure at listening position T2.

[0038] This makes it possible to present sound images of the sound source object OB from a distance as viewed from the listening positions T1, T2, etc., ranging from a distant position to a nearby position.

[0039] [Sound source object playback device] Next, a sound source object reproducing device according to an embodiment of the present invention will be described. Fig. 2 is a block diagram showing an example of the configuration of a sound source object reproducing device according to an embodiment of the present invention. This sound source object reproducing device 1 includes a parameter acquisition unit 10 and a sound pressure calculation unit 11.

[0040] The parameter acquisition unit 10 acquires various parameters by a process of modeling the sound source object, and outputs the various parameters to the sound pressure calculation unit 11 .

[0041] The various parameters acquired by the parameter acquisition unit 10 include the position coordinate a of the sound source object, the radius r of the circumscribing sphere of the sound source object, and the expansion coefficient C of the spherical harmonic function used when expanding the sound pressure distribution of the sound source object. mn (ω), and the position coordinates a of each sound-producing part obtained by dividing the sound source object l , the radius of the circumscribing sphere of each sound-producing part is r l , and the expansion coefficient C of the spherical harmonic function used to expand the sound pressure distribution of each sound-producing part mn l The parameter acquisition unit 10 will be described in detail later.

[0042] The subscript l (L) indicates the number of the sound part (a positive integer). In the example of Fig. 1, l=1 for the tire, which is the sound part HA-1, l=2 for the engine, which is the sound part HA-2, and l=3 for the siren, which is the sound part HA-3.

[0043] The sound pressure calculation unit 11 inputs various parameters from the parameter acquisition unit 10 as well as the coordinates of the listening position (listening position coordinate c). Then, based on the position coordinate a of the sound source object, the radius r of the circumscribing sphere of the sound source object, and the listening position coordinate c, the sound pressure calculation unit 11 determines whether the listening position is outside or inside the circumscribing sphere of the sound source object.

[0044] When the sound pressure calculation unit 11 determines that the listening position is outside the circumscribing sphere of the sound source object, it calculates and outputs the sound pressure p at the listening position by the above-mentioned conventional technology. On the other hand, when the sound pressure calculation unit 11 determines that the listening position of the sound source object is inside the circumscribing sphere, it calculates and outputs the sound pressure p at the listening position by superimposing the sound waves of each sound generating portion.

[0045] Specifically, the sound pressure calculation unit 11 determines whether the listening position is outside or inside the circumscribing sphere of each of the multiple sound generating parts. If the sound pressure calculation unit 11 determines that the listening position is outside the circumscribing sphere of the sound generating part, it calculates the sound pressure of the listening position from the sound generating part by the above-mentioned conventional technology.

[0046] On the other hand, when the sound pressure calculation unit 11 determines that the listening position is inside the circumscribing sphere of the sound generating part, it sets a preset fixed value (e.g., 0 (silence)) to the sound pressure of the listening position from the sound generating part. Then, the sound pressure calculation unit 11 adds up the sound pressures of the listening position from the sound generating part calculated or set for each sound generating part, and outputs the sum as the sound pressure p of the listening position.

[0047] When it is determined that the listening position is inside the circumscribing sphere of the sound generating part, the sound generating part may be further divided into a plurality of sound generating parts by the modeling process of the parameter acquiring unit 10 (see FIG. 9 described later). In this case, the sound pressure calculating unit 11 determines whether the listening position is inside or outside for each of the plurality of sound generating parts set by dividing the sound generating part, in the same manner as described above, and calculates and adds the sound pressures of the listening position to calculate the sound pressure of the sound generating part.

[0048] In this way, the sound pressure calculation unit 11 recursively determines whether the listening position is inside or outside, and calculates the sound pressure at the listening position, according to the hierarchy of the sound source object and the sound generation part set by dividing the sound generation part in the modeling process of the parameter acquisition unit 10. The sound pressure calculation unit 11 will be described in detail later.

[0049] (Parameter Acquisition Unit 10) Next, a detailed description will be given of the parameter acquisition unit 10 shown in Fig. 2. Fig. 3 is a block diagram showing an example of the configuration of the parameter acquisition unit 10, and Fig. 4 is a flowchart showing an example of the processing performed by the parameter acquisition unit 10.

[0050] The parameter acquisition unit 10 includes a sound source object parameter acquisition unit 20, a sound generating part determination unit 21, and a sound generating part parameter acquisition unit 22. The modeling and description procedures of the sound source object will be described with reference to Figs.

[0051] The sound source object parameter acquisition unit 20 of the parameter acquisition unit 10 determines the circumscribing sphere of the sound source object by manual operation or by image processing or sensing processing to recognize the sound source object, obtains the center position of the circumscribing sphere, and sets this as the position coordinate a of the sound source object (step S401).

[0052] The sound source object parameter acquisition unit 20 obtains the radius r of the circumscribing sphere of the sound source object determined in step S401, and acquires the sound pressure distribution on the circumscribing sphere (step S402). This sound pressure distribution is acquired by actual measurement or by calculation processing such as computer simulation. The sound pressure distribution may be a continuous distribution on the sphere, or may be a distribution discretized at regular intervals.

[0053] The sound source object parameter acquisition unit 20 performs spherical harmonic expansion of the acquired sound pressure distribution based on the above-mentioned formula (1) which shows the sound pressure distribution on the circumscribing sphere of the sound source object, and obtains an expansion coefficient C for each angular frequency ω. mn (ω) is calculated (step S403). In this case, by limiting the order n of the spherical harmonic function, the expansion coefficient C for each angular frequency ω is calculated. mn (ω) may be approximated.

[0054] In this way, in steps S401 to S403, the sound source object parameter acquisition unit 20 obtains the position coordinates a of the sound source object, the radius r of the circumscribed sphere, and the expansion coefficient C mn The parameters (ω) are obtained.

[0055] The sound generating part determination unit 21 manually determines a plurality of sound generating parts (sound generating parts of the sound generating object) from the sound generating object according to the modeling operation of the sound generating object by the operator (step S404). In other words, the sound generating object that emits sound waves is modeled and described as a sound generating object having a plurality of sound generating parts.

[0056] In the example shown in FIG. 1, an ambulance, which is a sound source object OB, is divided into sound parts HA-1, HA-2, and HA-3, which are tires, an engine, and a siren, and three sound parts HA-1, HA-2, and HA-3 are determined.

[0057] The sound production portion parameter acquisition unit 22 repeats the processes of steps S405 to S407, which will be described later, for each of the plurality of sound production portions determined by the sound production portion determination unit 21 in step S404.

[0058] The sound-producing part parameter acquisition unit 22 determines the circumscribing sphere of the sound-producing part by manual operation or by image processing or sensing processing for recognizing the sound-producing part, obtains the center position of the circumscribing sphere of the sound-producing part, and defines this as the position coordinates a of the sound-producing part. l (Step S405).

[0059] The sound-producing part parameter acquisition unit 22 calculates the radius r of the circumscribed sphere of the sound-producing part determined in step S405. l is calculated to obtain the sound pressure distribution on the circumscribed sphere (step S406). This sound pressure distribution is obtained by actual measurement or by calculation processing such as computer simulation, as in step S402. The sound pressure distribution may be a continuous distribution on the sphere, or may be a distribution discretized at regular intervals.

[0060] The sound-producing part parameter acquisition unit 22 performs a spherical harmonic expansion of the sound pressure distribution based on the following equation, which shows the sound pressure distribution on the circumscribing sphere of the sound-producing part, and obtains an expansion coefficient C for each angular frequency ω: mn l (ω) is calculated (step S407). In this case, by limiting the order n of the spherical harmonic function, the expansion coefficient C for each angular frequency ω is calculated. mn l (ω) may be approximated.

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[0061] The sound part parameter acquisition unit 22 judges whether or not the processing (the processing of steps S405 to S407) is completed for all sound parts (step S408). When the sound part parameter acquisition unit 22 judges in step S408 that the processing is not completed for all sound parts (step S408: N), it sets the next sound part (step S409) and proceeds to step S405. As a result, the processing of steps S405 to S407 is performed for the next sound part.

[0062] On the other hand, if it is determined in step S408 that the processing has been completed for all the sound generation parts (step S408: Y), the sound generation part parameter obtaining unit 22 proceeds to step S410.

[0063] In this way, in steps S405 to S407, the sound-producing part parameter acquisition unit 22 obtains the position coordinates a of the sound-producing part for each of the plurality of sound-producing parts. l , radius of circumscribing sphere r l and the expansion coefficient C mn l The parameters (ω) are obtained.

[0064] The parameter acquisition unit 10 proceeds from step S408(Y) to acquire the position coordinates a of the sound source object, the radius r of the circumscribed sphere, and the expansion coefficients C mn (ω), and the position coordinates of each sound-producing part a l , radius of circumscribing sphere r l and the expansion coefficient C mn l The parameters (ω) are stored as parameters of the model and description of the sound source object, and are output to the sound pressure calculation unit 11 (step S410).

[0065] (Sound pressure calculation section 11) Next, a detailed description will be given of the sound pressure calculation unit 11 shown in Fig. 2. Fig. 5 is a block diagram showing an example of the configuration of the sound pressure calculation unit 11, and Fig. 6 is a flowchart showing an example of the processing performed by the sound pressure calculation unit 11.

[0066] The sound pressure calculation unit 11 includes a sound source object position processing unit 30, a listening position determination unit 31, an outer sound pressure calculation unit 32, and an inner sound pressure calculation unit 33. The procedure for calculating the sound pressure p at the listening position will be described with reference to Figs. 5 and 6.

[0067] The sound pressure calculation unit 11 inputs the listening position coordinates c set by the operator, and also receives the position coordinates a of the sound source object, the radius r of the circumscribed sphere, and the expansion coefficient C mn (ω), and the position coordinates of each sound-producing part a l , radius of circumscribing sphere rl and the expansion coefficient C mn l The parameters (ω) are input (step S601).

[0068] The sound source object position processing unit 30 of the sound pressure calculation unit 11 calculates the distance r0 between the sound source object and the listening position and the direction (θ0, φ0) from the sound source object to the listening position based on the position coordinate a of the sound source object and the listening position coordinate c (step S602). Then, the sound source object position processing unit 30 outputs the distance r0 to the listening position determination unit 31 and outputs the direction (θ0, φ0) to the outside sound pressure calculation unit 32.

[0069] The listening position determination unit 31 receives the distance r0 from the sound source object position processing unit 30. Then, the listening position determination unit 31 determines whether the distance r0 between the sound source object and the listening position is greater than the radius r of the circumscribing sphere of the sound source object (step S603).

[0070] If the listening position determination unit 31 determines in step S603 that the distance r0 is greater than the radius r (step S603: Y), it determines that the listening position is outside the circumscribed sphere of the sound source object. Then, the listening position determination unit 31 outputs the determination result indicating the outside to the outer sound pressure calculation unit 32.

[0071] The outside sound pressure calculation unit 32 inputs the direction (θ0, φ0) from the sound source object position processing unit 30 and the determination result indicating the outside from the listening position determination unit 31. When the outside sound pressure calculation unit 32 inputs the determination result indicating the outside, the expansion coefficient C mn Based on (ω), the sound pressure p at the listening position in the direction (θ0, φ0) is calculated using the following formula: v (r0, θ0, φ0, ω) is calculated (step S604).

number

[0072] The outside sound pressure calculation unit 32 calculates the sound pressure at the listening position p(r0, θ0, φ0, ω)=p v (r0, θ0, φ0, ω) is output (step S605).

[0073] On the other hand, if the listening position determination unit 31 determines in step S603 that the distance r0 is not greater than the radius r (step S603: N), it determines that the listening position is inside the circumscribed sphere of the sound source object. Then, the listening position determination unit 31 outputs the determination result indicating the inside to the inside sound pressure calculation unit 33.

[0074] The inside sound pressure calculation unit 33 receives the determination result indicating the inside from the listening position determination unit 31. When the inside sound pressure calculation unit 33 receives the determination result indicating the inside, it calculates the listening position coordinate c and the position coordinates a of each sound generating part input from the parameter acquisition unit 10. l , radius of circumscribing sphere r l and the expansion coefficient C mn l Based on (ω), the sound pressure calculation process of the sound source object calculates the sound pressure p0 at the listening position by superposing the sound waves from each sound generating part (step S606). Then, the inside sound pressure calculation unit 33 outputs the sound pressure p=p0 at the listening position (step S607). Details of the inside sound pressure calculation process of the sound source object by the inside sound pressure calculation unit 33 in step S606 will be described later.

[0075] (Inner sound pressure calculation unit 33) Next, the details of the process of calculating the inside sound pressure of the sound source object in step S606 shown in FIG. 6 by the inside sound pressure calculation unit 33 shown in FIG. 5 will be described.

[0076] Fig. 7 is a block diagram showing an example of the configuration of the inside sound pressure calculation unit 33, and Fig. 8 is a flowchart showing an example of the processing of the inside sound pressure calculation unit 33. The flowchart in Fig. 8 shows the inside sound pressure calculation processing of the sound source object in step S606 shown in Fig. 6 and the sound pressure p=p0 output processing of the listening position in step S607.

[0077] As described above, when the distance r0 between the sound source object and the listening position is not greater than the radius r of the circumscribing sphere of the sound source object and the listening position is inside the circumscribing sphere of the sound source object, the inside sound pressure calculation unit 33 calculates the listening position coordinate c and the position coordinates a of each sound generating part. l , radius of circumscribing sphere r l and the expansion coefficient C mn l Based on (ω), the sound pressure calculation process inside the sound source object calculates the sound pressure p0 at the listening position by superimposing the sound waves from each sound-producing part.

[0078] 7, the inside sound pressure calculation unit 33 includes sound generation portion sound pressure calculation units 40-1, 40-2, . . . and an adder unit 41. As shown in FIG.

[0079] 1, the inside sound pressure calculation unit 33 includes sound generation portion sound pressure calculation units 40-1, 40-2, and 40-3 and an adder 41. The sound generation portion sound pressure calculation unit 40-1 calculates the sound pressure at the listening position from the tire, which is the sound generation portion HA-1. The sound generation portion sound pressure calculation unit 40-2 calculates the sound pressure at the listening position from the engine, which is the sound generation portion HA-2. The sound generation portion sound pressure calculation unit 40-3 calculates the sound pressure at the listening position from the siren, which is the sound generation portion HA-3.

[0080] Specifically, the sound pressure calculation unit 40-1 calculates the listening position coordinate c and the position coordinate a of the sound pressure part HA-1 for the tire, which is the first sound pressure part HA-1. l , radius of circumscribing sphere r l and the expansion coefficient C mn l Based on (ω), it is determined whether the listening position is outside the circumscribing sphere of the sound producing part HA-1. If the sound producing part sound pressure calculation unit 40-1 determines that the listening position is outside the circumscribing sphere of the sound producing part HA-1, it calculates the sound pressure of the listening position from the sound producing part HA-1 using the conventional technology described above. On the other hand, if the sound producing part sound pressure calculation unit 40-1 determines that the listening position of the sound producing part HA-1 is inside the circumscribing sphere, it sets a preset fixed value to the sound pressure of the listening position from the sound producing part HA-1.

[0081] The sound production portion sound pressure calculation unit 40-2 performs the same process as the sound production portion sound pressure calculation unit 40-1 for the engine, which is the second sound production portion HA-2, and obtains the sound pressure at the listening position from the sound production portion HA-2. The sound production portion sound pressure calculation unit 40-3 performs the same process as the sound production portion sound pressure calculation unit 40-1 for the siren, which is the third sound production portion HA-3, and obtains the sound pressure at the listening position from the sound production portion HA-3.

[0082] The adder 41 receives and adds the sound pressures at the listening position from the sound generation portion sound pressure calculators 40-1, 40-2, etc., and outputs the addition result as the sound pressure p0 at the listening position.

[0083] 7 and 8, when the listening position is inside the circumscribed sphere of the sound source object, the inside sound pressure calculation unit 33 inputs the listening position coordinates c and the position coordinates a of each sound generating part. l , radius of circumscribing sphere r l and the expansion coefficient C mn l (ω) is input (step S801).

[0084] The sound generation portion sound pressure calculation units 40-1, 40-2, etc. of the inside sound pressure calculation unit 33 repeat the processes of steps S802 to S805, which will be described later, for the corresponding sound generation portions.

[0085] When the sound generation part sound pressure calculation unit 40-1 processes the first sound generation part, first, the sound generation part position processing unit 50 of the sound generation part sound pressure calculation unit 40-1 calculates the position coordinates a l Based on the listening position coordinate c, the distance r0 between the sound-producing part and the listening position l , and the direction from the sound source to the listening position (θ0 l ,φ0 l ) (step S802). Then, the sound-producing part position processor 50 calculates the distance r0 l to the listening position determination unit 51, and the direction (θ l ,φ0 l ) to the outside sound pressure calculation unit 52.

[0086] The listening position determination unit 51 is located at a distance r0 lThen, the listening position determination unit 51 inputs the distance r0 between the sound generating part and the listening position. l is the radius of the circumscribing sphere of the sound-producing part, r l It is determined whether it is greater than (step S803).

[0087] In step S803, the listening position determination unit 51 determines the distance r0 l is the radius r l (step S803: Y), the listening position is determined to be outside the circumscribed sphere of the sound generation part. Then, the listening position determination unit 51 outputs the determination result indicating the outside to the outer sound pressure calculation unit 52.

[0088] The outer sound pressure calculation unit 52 calculates the sound pressure from the sound generation portion position processing unit 50 in the direction (θ l ,φ0 l ), and receives the determination result indicating the outside from the listening position determination unit 51. Then, when the determination result indicating the outside is received, the outside sound pressure calculation unit 52 calculates the expansion coefficient C mn l Based on (ω), the direction (θ0 l ,φ0 l ) sound pressure at the listening position from the sound-producing part in question p0 l (r0 l ,θ0 l ,φ0 l , ω) is calculated (step S804), and the process proceeds to step S806.

number

[0089] On the other hand, in step S803, the listening position determination unit 51 determines the distance r0 l is the radius r lIf it is determined that the listening position is not larger than (step S803: N), it is determined that the listening position is inside the circumscribed sphere of the sound generating part. Then, the listening position determination unit 51 outputs the determination result indicating the inside to the inside sound pressure processing unit 53.

[0090] The inside sound pressure processing unit 53 receives the determination result indicating the inside from the listening position determination unit 51. When the inside sound pressure processing unit 53 receives the determination result indicating the inside, it sets a preset fixed value as the sound pressure p0 l (r0 l ,θ0 l ,φ0 l , ω) (step S805), and the process proceeds to step S806. l (r0 l ,θ0 l ,φ0 l , ω) to the adder 41.

[0091] Thus, the distance r0 l is the radius r l If the sound pressure at the listening position is outside the circumscribing sphere of the sound generating part, the sound pressure at the listening position from the sound generating part p0 is input to the adder 41 from the outside sound pressure calculation unit 52. l (r0 l ,θ0 l ,φ0 l ,ω) is output. On the other hand, the distance r0 l is the radius r l If the sound pressure level is not greater than p0 and the listening position is inside the circumscribing sphere of the sound generating part, the sound pressure level p0 at the listening position from the sound generating part, which is a fixed value, is input from the inner sound pressure processing unit 53 to the adder 41. l (r0 l ,θ0 l ,φ0 l ,ω) is output.

[0092] The inside sound pressure processing unit 53 proceeds from steps S804 and S805 to determine whether or not the processing (the processing of steps S802 to S805) has been completed for all sound production parts (step S806). If the inside sound pressure processing unit 53 determines in step S806 that the processing has not been completed for all sound production parts (step S806: N), it sets the next sound production part (step S807) and proceeds to step S802.

[0093] As a result, the sound production portion sound pressure calculation unit 40-2 performs the process of steps S802 to S805 for the second sound production portion, and then the process of steps S802 to S805 is completed for all sound production portions.

[0094] If it is determined in step S806 that the processing has been completed for all sound generation parts (step S806: Y), the inside sound pressure processing unit 53 proceeds to step S808.

[0095] In this way, for each of all sound generating parts, the sound pressure p0 l (r0 l ,θ0 l ,φ0 l , ω) is output, or the inside sound pressure processing unit 53 outputs a fixed value sound pressure p0 l (r0 l ,θ0 l ,φ0 l ,ω) is output.

[0096] The addition unit 41 proceeds from step S806 (Y) and calculates the sound pressure p0 l (r0 l ,θ0 l ,φ0 l , ω) are input. Then, the adder 41 calculates the sound pressure p0 l (r0 l ,θ0 l ,φ0l , ω) is added (step S808).

number

[0097] The adder 41 outputs the addition result as the sound pressure p0 at the listening position due to the superposition of the sound waves from each sound generating part (step S809). In other words, the sum of the sound pressures due to the contributions of all sound generating parts becomes the sound pressure p0 at the listening position.

[0098] As described above, according to the sound source object reproducing device 1 of the embodiment of the present invention, the parameter acquisition unit 10 acquires the position coordinate a of the sound source object, the radius r of the circumscribed sphere, and the expansion coefficient C mn (ω), and the position coordinates of each sound-producing part a l , radius of circumscribing sphere r l and the expansion coefficient C mn l Get (ω).

[0099] The sound pressure calculation unit 11 judges whether the listening position is outside or inside the circumscribing sphere of the sound source object based on the position coordinate a of the sound source object and the listening position coordinate c. If the sound pressure calculation unit 11 judges that the listening position is outside the circumscribing sphere of the sound source object, it calculates the sound pressure p of the listening position p=p v On the other hand, when the sound pressure calculation unit 11 determines that the listening position of the sound source object is inside the circumscribing sphere, it determines for each of the multiple sound producing parts whether the listening position is outside or inside the circumscribing sphere of the sound producing part.

[0100] When the sound pressure calculation unit 11 determines that the listening position is outside the circumscribing sphere of the sound generating part, it calculates the sound pressure of the listening position from the sound generating part by the above-mentioned conventional technology. On the other hand, when the sound pressure calculation unit 11 determines that the listening position is inside the circumscribing sphere of the sound generating part, it sets a preset fixed value to the sound pressure of the listening position from the sound generating part. Then, the sound pressure calculation unit 11 adds the sound pressure of the listening position from the sound generating part calculated or set for each sound generating part, and outputs the sum result as the sound pressure of the listening position p=p0.

[0101] This allows the sound pressure at the listening position to be calculated even if the listening position is close to the sound source, and the sound source object can be reproduced at that position. In other words, since the sound pressure at the listening position is calculated according to the distance from the sound source object to the listening position, it is possible to present sound images from long distances to close distances.

[0102] [Example of a model in which a pronunciation part is further divided into multiple pronunciation parts] So far, we have explained the case where the sound source object is composed of multiple sound generating parts, but the sound generating parts may be further divided. In this case, the original sound generating parts when divided are treated as new sound source objects, and the new sound generating parts set by the division are treated as sound generating parts of the new sound source objects, and the processing of steps S802 to S805 shown in FIG. 8 is repeated recursively.

[0103] Fig. 9 is a diagram for explaining an example of a model in which the sound generation part is further divided. In this example, the engine, which is the sound generation part HA-2 in Fig. 1, is treated as a new sound source object OB-2, and the engine, which is the sound generation part HA-2, is further divided into a part A, which is a sound generation part (detailed sound generation part) HA-21, and a part B, which is a sound generation part (detailed sound generation part) HA-22.

[0104] In this model, an ambulance, which is a sound source object OB, is divided into three sound producing parts HA-1, HA-2, and HA-3, which are the tires, engine, and siren, and the engine, which is the sound producing part HA-2, is divided into part A, which is the sound producing part HA-21, and part B, which is the sound producing part HA-22.

[0105] In this case, the sound production part determination unit 21 of the parameter acquisition unit 10 of the sound source object reproduction device 1 manually determines three sound production parts HA-1, HA-2, HA-3, which are tires, an engine, and a siren, for the ambulance, which is the sound source object OB, in step S404 of Fig. 4. In addition, the sound production part determination unit 21 manually determines two sound production parts, part A, which is the sound production part HA-21, and part B, which is the sound production part HA-22, for the engine, which is the sound production part HA-2.

[0106] Then, the parameter acquisition unit 10 obtains the position coordinates a of the sound source object OB, the radius r of the circumscribed sphere, and the expansion coefficients C mn (ω), and the position coordinates a for each of the sound-producing parts HA-1 to HA-3, HA-21, and HA-22 l , radius of circumscribing sphere r l and the expansion coefficient C mn l The parameters consisting of (ω) are acquired and stored as parameters of the model and description of the sound source object OB, and are output to the sound pressure calculation unit 11.

[0107] Fig. 10 is a block diagram showing an example of the configuration of the inside sound pressure calculation unit 33 provided in the sound pressure calculation unit 11 in the example of Fig. 9. This inside sound pressure calculation unit 33 includes a sound generation part sound pressure calculation unit 40-1 for the sound generation part HA-1 (tire), a sound generation part sound pressure calculation unit 40-2 for the sound generation part HA-2 (engine), a sound generation part sound pressure calculation unit 40-3 for the sound generation part HA-3 (siren), and an adder 41.

[0108] The sound generation part sound pressure calculation units 40-1 and 40-3 include a sound generation part position processing unit 50, a listening position determination unit 51, an outer sound pressure calculation unit 52, and an inner sound pressure processing unit 53. The sound generation part sound pressure calculation unit 40-2 includes a sound generation part position processing unit 50, a listening position determination unit 51, an outer sound pressure calculation unit 52, and an inner sound pressure processing unit 53' that is different from the inner sound pressure processing unit 53.

[0109] The sound pressure calculation unit 40-1 performs the same process as the sound pressure calculation unit 40-1 shown in FIG. 7, and calculates the listening position coordinate c and the position coordinate a for the tire, which is the sound generation portion HA-1. l , radius r l and the expansion coefficient C mn l Based on (ω), the sound pressure of the listening position from the sound producing part HA-1 is calculated depending on whether the listening position is outside the circumscribed sphere of the sound producing part HA-1. Then, the sound producing part sound pressure calculation part 40-1 outputs the sound pressure of the listening position from the sound producing part HA-1 to the addition part 41.

[0110] The sound pressure calculation unit 40-2 calculates the sound pressure of the engine, which is the sound generation part HA-2, by calculating the listening position coordinate c and the position coordinate a l , radius r l and the expansion coefficient C mn l If it is determined based on (ω) that the listening position is outside the circumscribing sphere of the sound producing part HA-2, the outer sound pressure calculation unit 52 calculates the sound pressure at the listening position from the sound producing part HA-2, as described above.

[0111] On the other hand, if the sound production part sound pressure calculation unit 40-2 determines that the listening position is inside the circumscribed sphere of the sound production part HA-2, the inner sound pressure processing unit 53' calculates the sound pressure at the listening position by superimposing sound waves from part A, which is the sound production part HA-21, and part B, which is the sound production part HA-22.

[0112] The sound pressure calculation unit 40-2 outputs to the addition unit 41 the sound pressure at the listening position from the sound production part HA-2 calculated by the outer sound pressure calculation unit 52, or the sound pressure at the listening position from the sound production part HA-2 calculated by the inner sound pressure processing unit 53'.

[0113] As shown in Figure 10, the inner sound pressure processing unit 53' has a configuration similar to that of the inner sound pressure calculation unit 33 shown in Figure 7, and includes a sound production part sound pressure calculation unit 40-2-1 for the sound production part HA-21 (part A), a sound production part sound pressure calculation unit 40-2-2 for the sound production part HA-22 (part B), and an adder unit 41'.

[0114] The sound pressure calculation unit 40-2-1 performs the same process as the sound pressure calculation unit 40-1 shown in FIG. 7, and calculates the listening position coordinate c and the position coordinate a for the part A, which is the sound generation part HA-21. l , radius r l and the expansion coefficient C mn l Based on (ω), the sound pressure of the listening position from the sound producing part HA-21 is calculated depending on whether the listening position is outside the circumscribing sphere of the sound producing part HA-21. Then, the sound producing part sound pressure calculation unit 40-2-1 outputs the sound pressure of the listening position from the sound producing part HA-21 to the addition unit 41'.

[0115] Similarly, the sound production part sound pressure calculation unit 40-2-2 calculates the sound pressure at the listening position from the sound production part HA-22 for the part B, which is the sound production part HA-22. Then, the sound production part sound pressure calculation unit 40-2-2 outputs the sound pressure at the listening position from the sound production part HA-22 to the addition unit 41'.

[0116] The adder 41' inputs the sound pressure at the listening position from the sound production part HA-21 from the sound production part sound pressure calculation part 40-2-1, and also inputs the sound pressure at the listening position from the sound production part HA-22 from the sound production part sound pressure calculation part 40-2-2. The adder 41' then adds these sound pressures and outputs the addition result to the adder 41.

[0117] The sound pressure calculation unit 40-3 performs the same process as the sound pressure calculation unit 40-1 shown in FIG. 7, and calculates the listening position coordinate c and the position coordinate a for the sound pressure calculation unit HA-3, which is the siren. l , radius r l and the expansion coefficient C mn lBased on (ω), the sound pressure of the listening position from the sound producing part HA-3 is calculated depending on whether the listening position is outside or inside the circumscribed sphere of the sound producing part HA-3. Then, the sound producing part sound pressure calculation part 40-3 outputs the sound pressure of the listening position from the sound producing part HA-3 to the addition part 41.

[0118] 9, the sound production part HA-2 is treated as a new sound source object OB-2, and the sound production parts HA-21 and HA-22 are treated as sound production parts of the new sound source object OB-2. Then, the sound pressures at the listening position from the sound production parts HA-21 and HA-22 are recursively calculated by the sound production part sound pressure calculation units 40-2-1 and 40-2-2.

[0119] It should be noted that a plurality of sound source objects can be treated as a set instead of the example shown in Fig. 9. Fig. 11 is a diagram for explaining an example of a model in the case where a plurality of sound source objects are treated as a set.

[0120] 11, the sound source part determination unit 21 provided in the parameter acquisition unit 10 of the sound source object reproduction device 1 manually sets sound source objects OB-1, OB-2, and OB-3 according to the modeling operation of the sound source objects by the operator, and then defines a set of these sound source objects OB-1, OB-2, and OB-3 as a new sound source object OB-10.Then, the sound source part determination unit 21 defines the sound source objects OB-1, OB-2, and OB-3 as sound sources of the new sound source object OB-10.

[0121] The sound source object reproducing device 1 shown in FIG. 2 can also be applied to the model shown in the example of FIG.

[0122] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the technical concept thereof.

[0123] For example, the numbers of sound source objects and sound generating portions shown in FIG. 1, FIG. 9, and FIG. 11 are merely examples, and the present invention can be applied to any numbers.

[0124] A normal computer can be used as the hardware configuration of the sound source object reproducing device 1 according to the embodiment of the present invention. The sound source object reproducing device 1 is configured by a computer including a CPU, a volatile storage medium such as a RAM, a non-volatile storage medium such as a ROM, an interface, etc.

[0125] The functions of the parameter acquisition unit 10 and the sound pressure calculation unit 11 provided in the sound source object reproduction device 1 are realized by causing a CPU to execute a program in which these functions are written.

[0126] These programs are stored in the storage medium and are read and executed by the CPU. These programs can also be distributed by storing them in a storage medium such as a magnetic disk (floppy disk, hard disk, etc.), an optical disk (CD-ROM, DVD, etc.), or a semiconductor memory, and can also be transmitted and received via a network. [Explanation of symbols]

[0127] 1. Sound source object playback device 10 Parameter Acquisition Section 11 Sound pressure calculation section 20 Sound source object parameter acquisition unit 21 Pronunciation part determination unit 22 Sound generation part parameter acquisition unit 30 Sound source object position processing unit 31,51 Listening position determination unit 32,52 Outside sound pressure calculation section 33 Inside sound pressure calculation unit 40-1, 40-2, 40-3, 40-2-1, 40-2-2 Sound pressure calculation part 41,41' Addition section 50 Sound generation part position processing part 53,53' Inner sound pressure processing section OB, OB-1, OB-2, OB-3, OB-10 sound source object HA-1,HA-2,HA-3,HA-21,HA-22 Sound part T1, T2 listening positions a Position coordinates of the sound source object r Radius of the circumscribing sphere of the sound source object C mn (ω) Spherical harmonic expansion coefficients used to expand the sound pressure distribution of the sound source object a l Position coordinates of the sound producing part r l Radius of the circumscribing sphere of the sound-producing part C mn l (ω) Expansion coefficients of spherical harmonics used to expand the sound pressure distribution of the sound-producing part c Listening position coordinates p v ,p0,p0 l Sound pressure at listening position r,r0,r0 l distance θ,θ0,θ0 l Azimuth φ,φ0,φ0 l elevation angle p Sound pressure m order n degree Y n m ,Y,Y1,Y2,Y3,Y4 spherical harmonics ω,ω0 angular frequency h n Spherical Hankel functions

Claims

1. 1. A sound source object reproducing device that obtains a sound pressure distribution on a sphere circumscribing a sound source object or a sphere containing the sound source object, and determines a sound pressure at a predetermined listening position based on the sound pressure distribution on the sphere, thereby reproducing a signal of the sound source object at the listening position, The position coordinate a of the sound source object is calculated, and the radius r of the sphere of the sound source object is calculated. The sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn The position coordinate a, the radius r, and the expansion coefficient C mn as a parameter of the sound source object, determining a plurality of sound generating portions from the sound source object according to an operation of modeling the sound source object by an operator; For each of the plurality of sound-producing parts, the position coordinates a of the sound-producing part l and the radius r of the sphere circumscribing the sound-producing portion or containing the sound-producing portion. l The sound pressure distribution on the sphere of the sound-generating portion is obtained, and the sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn l and calculate the position coordinate a l , the radius r l and the expansion coefficient C mn l a parameter acquisition unit that outputs the parameter for each of the plurality of sound generation portions; determining whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object output by the parameter acquisition unit; When it is determined that the listening position is outside the sphere of the sound source object, the expansion coefficient C included in the parameter of the sound source object mn Based on this, the sound pressure p v Seeking When it is determined that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l determining whether the listening position is outside or inside the sphere of the sound-generating portion based on When it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l Based on the above, a sound pressure from the sound generating part at the listening position is calculated, when it is determined that the listening position is inside the sphere of the sound-generating portion, a preset fixed value is set as the sound pressure at the listening position from the sound-generating portion; The sound pressure at the listening position for each of the plurality of sound generating parts is added to obtain the sound pressure p 0 A sound pressure calculation unit for calculating a sound pressure A sound source object reproducing device comprising:

2. 2. The sound source object reproducing apparatus according to claim 1, The sound pressure calculation unit Based on the position coordinate a and the coordinate of the listening position included in the parameters of the sound source object, a distance r between the sound source object and the listening position is calculated. 0 and the direction (θ 0 , φ 0 a sound source object position processor for calculating the sound source object position; The distance r calculated by the sound source object position processing unit 0 is greater than the radius r included in the parameters of the sound source object, and the distance r 0 is greater than the radius r, the listening position is determined to be outside the sphere of the sound source object, and the distance r 0 a first listening position determination unit that determines that the listening position is inside the sphere of the sound source object when it is determined that the radius r is not greater than the radius r; When the first listening position determination unit determines that the listening position is outside the sphere of the sound source object, the expansion coefficient C mn Based on this, the direction (θ 0 , φ 0 ) the sound pressure p v A first outside sound pressure calculation unit that calculates When the first listening position determination unit determines that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l determining whether the listening position is outside or inside the sphere of the sound-generating portion based on When it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l Based on the above, a sound pressure from the sound generating part at the listening position is calculated, when it is determined that the listening position is inside the sphere of the sound-producing portion, the fixed value is set to the sound pressure at the listening position from the sound-producing portion; The sound pressure at the listening position for each of the plurality of sound generating parts is added to obtain the sound pressure p 0 An inside sound pressure calculation unit for calculating A sound source object reproducing device comprising:

3. 3. The sound source object reproducing apparatus according to claim 2, the inner sound pressure calculation unit includes a sound portion sound pressure calculation unit corresponding to each of the plurality of sound portions, and an adder, The sound pressure calculation unit includes: The position coordinate a included in the parameters of the sound generating part l and based on the coordinates of the listening position, a distance r between the sound-producing part and the listening position 0 l and the direction from the sound generating part to the listening position (θ 0 l , φ 0 l a sound-producing portion position processing unit for calculating a sound-producing portion position; The distance r calculated by the sound generating portion position processing unit 0 l The radius r is included in the parameters of the sound generating portion. l and determining whether the distance r is greater than 0 l is the radius r l If it is determined that the distance r is greater than r, it is determined that the listening position is outside the sphere of the sound-generating portion. 0 l is the radius r l a second listening position determination unit that determines that the listening position is inside the sphere of the sound generating portion when it is determined that the listening position is not larger than When the second listening position determination unit determines that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l Based on this, the direction (θ 0 l , φ 0 l ) the first sound pressure p 0 l A second outside sound pressure calculation unit that calculates When the second listening position determination unit determines that the listening position is inside the sphere of the sound producing portion, the fixed value is set to the direction (θ 0 l , φ 0 l ) the second sound pressure p 0 l and an inner sound pressure processing unit for setting the The adding unit is The first sound pressure p calculated by the second outside sound pressure calculation unit 0 l or the second sound pressure p set by the inner sound pressure processing unit 0 l The sound pressure p 0 4. A sound source object reproducing device comprising:

4. 2. The sound source object reproducing apparatus according to claim 1, The parameter acquisition unit For the sound source object, the position coordinate a, the radius r and the expansion coefficient C mn as a parameter of the sound source object, determining the plurality of sound-producing parts from the sound source object according to an operation of modeling the sound source object by the operator, and further determining a plurality of detailed sound-producing parts from the sound-producing parts; For each of the plurality of pronunciation parts and the plurality of detailed pronunciation parts, the position coordinates a l , the radius r l and the expansion coefficient C mn l and outputting the parameters for each of the plurality of pronunciation parts and the plurality of detailed pronunciation parts; The sound pressure calculation unit determining whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object; When it is determined that the listening position is outside the sphere of the sound source object, the expansion coefficient C included in the parameter of the sound source object mn Based on this, the sound pressure p v Seeking When it is determined that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l determining whether the listening position is outside or inside the sphere of the sound-generating portion based on When it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l Based on the above, a sound pressure from the sound generating part at the listening position is calculated, When it is determined that the listening position is inside the sphere of the sound producing portion, for each of the plurality of detailed sound producing portions further determined from the sound producing portion by the parameter acquiring unit, the position coordinate a included in the parameter of the detailed sound producing portion is l and the radius r l determining whether the listening position is outside or inside the sphere of the detailed sound part based on When it is determined that the listening position is outside the sphere of the detailed sound part, the expansion coefficient C mn l Based on the above, a sound pressure at the listening position from the detailed sound portion is calculated, when it is determined that the listening position is inside the sphere of the detailed sound portion, the fixed value is set to a sound pressure of the listening position from the detailed sound portion; by adding up the sound pressures at the listening position for each of the plurality of detailed sound portions, a sound pressure at the listening position in the sound portion is obtained; The sound pressure at the listening position for each of the plurality of sound generating parts is added to obtain the sound pressure p 0 4. A sound source object reproducing device comprising:

5. a sound source object reproducing device that obtains a sound pressure distribution on a sphere that circumscribes a sound source object or a sphere that contains the sound source object, and obtains a sound pressure at a predetermined listening position based on the sound pressure distribution on the sphere, thereby reproducing a signal of the sound source object at the listening position; The position coordinate a of the sound source object is calculated, and the radius r of the sphere of the sound source object is calculated. The sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn The position coordinate a, the radius r, and the expansion coefficient C mn as a parameter of the sound source object, determining a plurality of sound generating portions from the sound source object according to an operation of modeling the sound source object by an operator; For each of the plurality of sound-producing parts, the position coordinates a of the sound-producing part l and the radius r of the sphere circumscribing the sound-producing portion or containing the sound-producing portion. l The sound pressure distribution on the sphere of the sound-generating portion is obtained, and the sound pressure distribution on the sphere is expanded into a spherical harmonic expansion coefficient C mn l and calculate the position coordinate a l , the radius r l and the expansion coefficient C mn l a parameter acquisition unit that outputs the parameter for each of the plurality of sound generation portions; determining whether the listening position is outside or inside the sphere of the sound source object based on the position coordinate a and the radius r included in the parameters of the sound source object output by the parameter acquisition unit; When it is determined that the listening position is outside the sphere of the sound source object, the expansion coefficient C included in the parameter of the sound source object mn Based on this, the sound pressure p v Seeking When it is determined that the listening position is inside the sphere of the sound source object, for each of the plurality of sound producing parts, the position coordinate a l and the radius r l determining whether the listening position is outside or inside the sphere of the sound-generating portion based on When it is determined that the listening position is outside the sphere of the sound-producing part, the expansion coefficient C mn l Based on the above, a sound pressure from the sound generating part at the listening position is calculated, when it is determined that the listening position is inside the sphere of the sound-generating portion, a preset fixed value is set as the sound pressure at the listening position from the sound-generating portion; The sound pressure at the listening position for each of the plurality of sound generating parts is added to obtain the sound pressure p 0 A program to function as a sound pressure calculation unit to calculate the sound pressure.

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