JP5010185B2 - 3D acoustic panning device - Google Patents

Description

  The present invention relates to a three-dimensional acoustic panning device, and more particularly to a three-dimensional acoustic panning device that can reproduce three-dimensional panning of a sound source as panning of a sound image formed by acoustic signals radiated from a plurality of speakers. .

  In an audio playback device such as a 2-channel audio system or 5.1 surround system, the output of a plurality of speakers arranged on the circumference centered on the sound receiving point is changed by a pan pod of a mixing console. Since the localization and movement of the sound image are adjusted, it is easy to pan the sound image in the left-right direction along the circumference, but it is difficult to pan the sound image in the up-down direction and the front-back direction.

  In view of this, devices that aim to pan the acoustic signal not only in the left-right direction but also three-dimensionally in the up-down direction and the front-rear direction have already been proposed (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1). .

  In other words, the apparatus disclosed in Patent Document 1 is capable of panning a sound image not only in the horizontal direction but also in the vertical direction by applying two FIR filters to two speakers arranged on the same plane.

  The device disclosed in Patent Document 2 not only selects a speaker to be used according to the position (angle, distance) of an object with the viewer as the origin, but also controls the volume output by the speaker to be used. This makes it possible to pan the sound image not only in the horizontal direction but also in the front-rear direction.

Furthermore, the apparatus disclosed in Non-Patent Document 1 can resolve the position vector of the sound source with the sound receiving point as the origin into speaker vectors facing the direction of the three speakers surrounding the sound source, so that it corresponds to the size of the speaker vector. A sound image can be reproduced at the same position as the sound source position by outputting sound signals from three speakers at a sound volume.
Japanese Patent No. 3177714 ([0012], FIG. 1) JP-A-6-301390 ([0010] to [0015], FIG. 1) “Localization of Amplitude-Panned Virtual Sources II: Two- and Three-Dimensional Panning” VILLE PULKKI, J. Audio Eng. Soc. Vol.49, No.9, 2001 September

  However, the device disclosed in Patent Document 1 has a problem that it is difficult to pan the sound image back and forth, and the devices disclosed in Patent Document 2 and Non-Patent Document 1 are based only on the amplitude of the acoustic signal. The sound image is panned in the front-rear direction, and there is a problem that accurate panning in the front-rear direction in consideration of the phase is difficult.

  The present invention has been made to solve the conventional problems, and can reproduce three-dimensional panning of a sound source as panning of a sound image formed by acoustic signals emitted from a plurality of speakers. An object is to provide a two-dimensional acoustic panning device.

The three-dimensional acoustic panning apparatus of the present invention includes a sound source acoustic signal acquisition unit that acquires a sound source acoustic signal radiated from at least one sound source, panning information input unit that inputs panning information for panning the sound source, and the sound source. A sound image forming sound signal output means for outputting a sound image forming sound signal for forming a sound image at a position, a placement information storage means for storing placement information of the sound image forming sound signal output means, the sound source sound signal, the panning information, and look including a sound image forming acoustic signal generation means for generating said sound image forming acoustic signal based on said layout information, said sound image forming acoustic signal generation means, a Fourier transform of said sound source sound signal into a frequency domain excitation acoustic signal conversion And a frequency domain sound image based on the frequency domain sound source acoustic signal, the panning information and the arrangement information A frequency domain sound image forming sound signal generating means for generating an synthesized sound signal; and an inverse transform means for inversely transforming the frequency domain sound image forming sound signal into the sound image forming sound signal that is a time function. A sound image acoustic physical quantity vector equal to a sound source acoustic physical quantity vector that is an acoustic physical quantity vector at a sound receiving point when the formed sound signal generating means pans the sound source that radiates the sound source acoustic signal based on panning information. The sound image forming acoustic signal to be formed is generated .

With this configuration, three-dimensional panning of a sound source can be reproduced as panning of a sound image formed by acoustic signals radiated from a plurality of speakers.
Also, with this configuration, a sound image forming sound signal can be generated based on the sound source sound signal, panning information, and arrangement information.
Also, with this configuration, the sound image can be panned three-dimensionally regardless of the arrangement of the speakers.

Stereophonic sound panning apparatus of the present invention, the panning information input means, and direction information input means for inputting the direction information of the sound source relative to the said sound receiving point, to said sound source relative to the said sound receiving point Distance information input means for inputting the distance information.

  With this configuration, panning information can be input as a combination of sound source direction information and distance information.

  In the three-dimensional acoustic panning apparatus of the present invention, the panning information input unit includes a panning information storage unit that stores the panning information.

  With this configuration, panning information can be stored.

  In the three-dimensional sound panning apparatus of the present invention, the sound image forming sound signal output means includes a recording / editing means for recording and editing the sound image forming sound signal.

  With this configuration, the sound image forming sound signal can be recorded and edited.

  The present invention can provide a three-dimensional acoustic panning device that can reproduce three-dimensional panning of a sound source as panning of a sound image formed by acoustic signals emitted from a plurality of speakers.

  Hereinafter, an embodiment of a three-dimensional acoustic panning apparatus according to the present invention will be described with reference to the drawings.

  In this specification, the acoustic physical quantity vector is an acoustic physical quantity of a sound receiving point that receives an acoustic signal radiated from a point sound source, that is, a vector having at least one of sound pressure or particle velocity as a component, or The sound intensity vector obtained by multiplying the particle velocity vector by the sound pressure that is the scalar quantity and integrating the particle velocity vector over a certain time interval is meant.

(First embodiment)
As shown in the block diagram of FIG. 1, the three-dimensional sound panning apparatus 1 of the first embodiment includes a sound source sound signal acquisition unit 11 that acquires a sound source sound signal s (t) emitted from at least one sound source C; Panning information input means 12 for inputting panning information for panning the sound source C, sound image forming acoustic signal output means 13 for outputting a sound image forming acoustic signal q (t) for forming a sound image at the position of the sound source C, and sound image formation generating a layout data storage unit 14 for storing the arrangement information I _s of the audio signal output unit 13, the sound source acoustic signal s (t), the panning information I _p and the arrangement information based on the I _s sound image forming acoustic signal q (t) And a sound image forming acoustic signal generating means 15 for performing.

The panning information input means 12 inputs direction information input means 121 for inputting sound source direction information I _pd with the sound receiving point G as a reference, and distance information I _pr to the sound source with the sound receiving point G as a reference. And distance information input means 122 may be included.

The panning information input unit 12 may further include a panning information storage unit 123 that stores the panning information I _p .

  The sound image forming sound signal output means 13 may include a recording / editing means 131 for recording and editing the sound image forming sound signal q (t).

The sound image forming sound signal generating means 15 includes a transforming means 151 for Fourier transforming the sound source sound signal s (t) to the frequency domain sound source sound signal S (ω), the frequency domain sound source sound signal S (ω), panning information I _p and arrangement information and frequency domain sound image forming acoustic signal generation means 152 for generating a frequency domain sound image forming acoustic signal Q (omega) which forms a sound image panning based on I _s, the frequency domain sound image forming acoustic signal Q a (omega) time function And inverse transforming means 153 for performing Fourier transform on the sound image forming acoustic signal q (t).

  FIG. 2 is a block diagram showing a hardware configuration of the three-dimensional acoustic panning apparatus 1 according to the present invention, and an analog / digital (A / D) converter 21 that reads a sound source acoustic signal s (t), and sound image formation. A digital / analog (D / A) converter 22 that outputs an acoustic signal q (t), a CPU 23 that executes a three-dimensional acoustic panning program, a memory 24 that stores a three-dimensional acoustic panning program, and a three-dimensional acoustic panning apparatus An interface (I / F) 25 to which peripheral devices for operating the device are connected is connected to the bus 20.

The I / F25, and the display panel 261, a keyboard 262, a mouse 263, a track ball 27 to enter a direction component information panning information I _p, and the Panpoddo 28 for inputting distance component information panning information I _p Connected. Note that a dedicated operation panel can be applied instead of the display panel 261, the keyboard 262, and the mouse 263.

  That is, the three-dimensional sound panning apparatus 1 according to the present invention is configured by installing a three-dimensional sound panning program in the computer 2.

  FIG. 3 is a perspective view of the trackball 27 (a) and the pan pod 28 (b).

  The trackball 27 has a structure in which the ball 272 is fitted in a hemispherical depression provided in the trackball base 271 and the ball 272 can be rotated in an arbitrary direction.

  By rotating the ball 272 with a finger or palm, it is possible to input the direction information (the direction and amount of rotation of the sound source) of the sound source C with the sound receiving point G as a reference.

  The pan pod 28 is, for example, a variable resistor, and distance information to the sound source C based on the sound receiving point G can be input by moving a knob 282 on the pan pod base 281 back and forth.

  FIG. 4 is a flowchart of the three-dimensional sound panning program installed in the memory 24. The CPU 23 first reads the sound source sound signal s (t) via the A / D converter 21 (step S41).

  The CPU 23 performs a Fourier transform on the sound source sound signal s (t) to calculate the frequency domain sound source sound signal S (ω) (step S42).

  Next, the CPU 23 performs a panning process to calculate the frequency domain sound image forming acoustic signal Q (ω) (step S43), and performs inverse Fourier transform on the frequency domain sound image forming acoustic signal Q (ω) to generate a time domain signal. The sound image forming acoustic signal q (t) is calculated (step S44).

  Details of the processes in steps S43 and S44 will be described later.

  Finally, the CPU 23 outputs the sound image forming acoustic signal q (t) via the D / A converter 22 (step S45) and ends this routine.

In step S43, the sound image acoustic physical quantity vector V equal to the sound source acoustic physical quantity vector R that is the acoustic physical quantity vector at the sound receiving point G when the sound source C that radiates the sound source acoustic signal s (t) is panned based on the panning information I _p. Is generated at the sound receiving point G, and a sound image forming acoustic signal q (t) is generated.

  First, an acoustic physical quantity vector at a sound receiving point when there is one point sound source and one sound receiving point will be described.

The sound pressure p (t, r) on the spherical surface having a radius r from the origin of the sound emitted from the point sound source arranged at the origin of the three-dimensional space is determined by the wave equation of [Equation 1].

Therefore, if the sound source acoustic signal applied to the point sound source is s (t), the sound pressure p (t, r) on the spherical surface having the radius r from the origin is expressed by [Equation 2].

The frequency domain representation of [Equation 2] is [Equation 3].

In the above equation, the sound pressure at one sound receiving point of the sound source acoustic signal s (t) radiated from one point sound source is inversely proportional to the distance from the point sound source to the sound receiving point, and from the point sound source to the sound receiving point. The sound pressure at one sound receiving point is the sound pressure transfer function G _p (ω, r), which is a function of the distance from the point sound source to the sound receiving point, and the frequency domain sound source sound signal S ( This shows that the product with ω) can be calculated by inverse Fourier transform.

  Since the distance from the point sound source to the sound receiving point and the propagation time of the acoustic signal are uniquely determined if the point sound source coordinates and the sound receiving point coordinates are determined in an arbitrary coordinate system, the sound pressure transfer function is also determined by the sound source coordinates in the coordinate system. If the sound receiving point coordinates are determined, they are uniquely determined.

If the particle velocity v (r, t) on the spherical surface with the radius r from the origin of the sound source acoustic signal radiated from the point sound source arranged at the origin of the three-dimensional space is the equation of motion on the spherical surface with the radius r 4].

Solving [Equation 4], the particle velocity v (r) can be expressed by [Equation 5].

The frequency domain representation of [Equation 5] is [Equation 6].

Therefore, the acoustic physical quantity vector P _k having both the sound pressure p (t, r) and the particle velocity v (t, r) at the sound receiving point k as components can be defined by [Equation 7].

The acoustic physical quantity vector P _k may include only one of the sound pressure p (t, r) or the particle velocity v (t, r) as a component.

Further, the acoustic physical quantity vector P _k is an instantaneous acoustic intensity II (t, r) that is a product of the sound pressure p (t, r) and the particle velocity v (t, r), or a time interval in which the instantaneous acoustic intensity is present. The sound intensity I (t, r), which is the integral value of

Here, the instantaneous sound intensity II (t, r) is defined by [Equation 8], and the sound intensity I (t, r) is defined by [Equation 9].

  In the following embodiments, a case where the acoustic physical quantity vector is a sound pressure will be described.

If the position of the sound source in the space with the sound receiving point G as the origin is represented by C (r _c (τ), θ _c (τ), φ _c (τ)), the origin of the sound source acoustic signal radiated from the sound source C The sound source sound pressure vector R which is the sound pressure vector at can be expressed by [Equation 10].

Further, the positions of the three speakers SP _i (i = 1, 2, 3) which are the sound image forming sound signal output means 13 are represented as SP _i (r _i , θ _i , φ _i ) as shown in FIG. The sound image sound pressure vector V that is the sound pressure vector at the origin when each speaker SP _i outputs the frequency domain sound image forming acoustic signal Q _i (ω) (i = 1, 2, 3) is expressed by [Equation 11]. be able to.

Here, if Q ₁ (ω), Q ₂ (ω), and Q ₃ (ω) are determined so that [Equation 12] is satisfied, and inversely transformed into the time domain and output from the speaker, the sound source acoustic signal s The situation in which (t) pans can be reproduced by outputting the sound image forming acoustic signal q (t) from a speaker arranged at a predetermined position.

In order to determine the sound image forming acoustic signals q ₁ (t), q ₂ (t), and q ₃ (t) so that [Equation 12] is satisfied, the sound source sound pressure represented by [Equation 13] is determined. The sound image forming acoustic signals q ₁ (t), q ₂ (t), and q ₃ (t) that minimize the square error E between the vector R and the sound image sound pressure vector V may be obtained.

When [Equation 10] and [Equation 11] are substituted into [Equation 13] and expanded, [Equation 14] is obtained.

When [Equation 14] is rewritten using [Equation 15], [Equation 16] is obtained.

The frequency domain sound image forming acoustic signal Q (ω) that minimizes the square error E can be determined by [Equation 17] in which E is partially differentiated with respect to Q (ω) and set to zero.

Therefore, the frequency domain sound image forming acoustic signal Q (ω) that minimizes the square error E is expressed by [Equation 18].

  The above is the processing of the panning routine in step S43.

As a process of step S44, [Formula 18] is subjected to inverse Fourier transform to calculate the sound image forming acoustic signal q _i (i = 1, 2, 3) represented by [Formula 19] output from the three speakers SP _i. To do.

Here, the parameters r ₁ , r ₂ , r ₃ , θ ₁ , θ ₂ , θ ₃ , φ ₁ , φ ₂ , φ ₃ are given as speaker position information, and the parameters θ (τ), φ (τ) are The track ball 27 shown in FIG. 3A is used for input, and the parameter r (τ) is input using the pan pod 28 shown in FIG. 3B.

  According to the first embodiment, it is possible to pan a sound image within a triangular pyramid having a sound receiving point as a vertex and a straight line connecting each of the sound receiving point and the three speakers as a ridge line.

(Second Embodiment)
In the second embodiment, four or more speakers are installed, and a sound image can be panned to an arbitrary position.

FIG. 6 is a perspective view for explaining a case where _eight speakers SP _{1 to} SP ₈ are installed and a sound image is panned to C _{1 to} C _{2. The} sound image has a sound receiving point G as a vertex and a sound receiving point G and From an initial position C ₁ in a triangular pyramid sound field (hereinafter referred to as sound field (SP ₂ , SP ₃ , SP ₄ )) whose line is a line connecting the _three speakers SP ₂ , SP ₃ , SP ₄ , Moves to the final position C ₂ in the sound field (SP ₅ , SP ₆ , SP ₇ ) via the sound field (SP ₃ , SP ₄ , SP ₆ ) and the sound field (SP ₄ , SP ₅ , SP ₆ ) Shows when to do.

Since the intersection between the locus of the sound image and the boundary surface of the sound field can be calculated in advance, any panning can be realized by applying the first embodiment for each sound field.
(Third embodiment)
Although the first embodiment and the second embodiment have described the case of panning one sound source, the present invention can also pan a plurality of sound sources whose relative positions are unchanged.

When there are M sound sources, assuming that the position of the m-th sound source is C _m (r _cm (τ), θ _cm (τ), φ _cm (τ)) (1 ≦ m ≦ M), M The sound source sound pressure vector R at the sound receiving point G by the sound source acoustic signal radiated from the sound source is expressed by [Equation 20].

When the positions of the three speakers SP _mi (i = 1, 2, 3) forming the sound field including the m-th sound source C _m are expressed as SP _mi (r _mi , θ _mi , φ _mi ), each speaker SP. overlapping of a sound image sound pressure _{vector mi} corresponds to the sound pressure vector in which the sound image sound pressure vector V _m, and each of M sound sources in the sound receiving point G when the output frequency domain sound image forming acoustic signal Q _mi (omega) The sound image sound pressure vector V at the sound receiving point G that is the combination is expressed by [Equation 21].

  Therefore, if the first and second embodiments are applied using [Equation 20] instead of [Equation 10] and [Equation 21] instead of [Equation 11], the relative position remains unchanged. It is possible to reproduce the situation of panning a plurality of sound sources at once.

(Fourth embodiment)
In the fourth embodiment, functions necessary for use in the production of a television program or a radio program are added to the three-dimensional sound panning apparatus according to the present invention, and the panning information storage for storing the panning information I _p is used. Means 123 and recording / editing means 131 for recording and editing the sound image forming acoustic signal q (t).

The panning information storage unit 123 has a function of storing panning information I _p that is operation information of the trackball 27 and the pan pod 28, and enables the same panning operation to be repeated for different sound sources.

  The recording / editing unit 131 has a function of recording and editing the sound image forming sound signal q (t), and can generate a sound image forming sound signal obtained by panning each of a plurality of sound sources. .

Here, consider a case where different panning operations are performed for each group on N groups of sound sources each having M _n sound sources.

If the position of the _mn th sound source of the _n th group is C _mn (r _cmn (τ), θ _cmn (τ), φ _cmn (τ)) (1 ≦ m _n ≦ M _n ), then M _n The sound source sound pressure vector R _{n at the} sound receiving point G formed by the sound source acoustic signals radiated from the sound sources of the sound sources, and M ₁ + M ₂ +... + M _N sound source acoustic signals radiated from all N groups. The sound source sound pressure vector R of the sound receiving point G to be formed is expressed by [Equation 22].

The positions of the three speakers SP _mni (i = 1, 2, 3) forming the sound field including the m _n -th sound source C _{mn of the n-} th group are _denoted by SP _mni (r _mni , θ _mni , φ _mni ). In other _words , the sound image sound pressure vector V _mn , which is the sound pressure vector at the sound receiving point G when each speaker SP _mni outputs the frequency domain sound image forming acoustic signal Q _mni (ω), M _n pieces of the _nth group. Sound image sound at sound receiving point G, which is a superposition of sound image sound pressure vectors V _n corresponding to sound sources of all N groups, and sound image sound pressure vector V _n at sound receiving point G, which is a superposition of sound image sound pressure vectors corresponding to the sound source The pressure vector V is expressed by [Equation 23].

  Therefore, by applying [Equation 22] instead of [Equation 10] and [Equation 23] instead of [Equation 11], applying the first embodiment and the second embodiment, a plurality of sound sources can be obtained. Each panning situation can be reproduced.

  As described above, the three-dimensional sound panning apparatus according to the present invention has an effect that the situation in which the sound source is panned three-dimensionally can be reproduced using the speaker arranged at a predetermined position. It is effective as an acoustic signal processing device.

The block diagram which shows the function structure of the three-dimensional sound panning apparatus which concerns on this invention. The block diagram which shows the hardware constitutions of the three-dimensional sound panning apparatus which concerns on this invention A perspective view of a trackball and a pan pod used in the three-dimensional acoustic panning apparatus according to the present invention. Flowchart of a panning routine installed in the three-dimensional acoustic panning apparatus according to the present invention Arrangement of three speakers constituting the sound field Layout of the eight speakers that make up the sound field

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Three-dimensional acoustic panning apparatus 11 Sound source acoustic signal acquisition means 12 Panning information input means 13 Sound image formation acoustic signal output means 14 Arrangement information storage means 15 Sound image formation acoustic signal generation means 121 Direction information input means 122 Distance information input means 123 Panning information storage 123 Means 131 Recording / editing means 151 Conversion means 152 Frequency domain sound image forming acoustic signal generation means 153 Inverse conversion means

Claims (4)

Sound source sound signal acquisition means for acquiring a sound source sound signal emitted by at least one sound source;
Panning information input means for inputting panning information for panning the sound source;
Sound image forming acoustic signal output means for outputting a sound image forming acoustic signal for forming a sound image at the position of the sound source;
Arrangement information storage means for storing arrangement information of the sound image forming acoustic signal output means;
The sound source audio signals, look including a sound image forming acoustic signal generation means for generating said sound image forming acoustic signal based on the panning information and the layout information,
The sound image forming acoustic signal generating means,
A transforming means for Fourier transforming the sound source acoustic signal into a frequency domain sound source acoustic signal;
A frequency domain sound image forming acoustic signal generating means for generating a frequency domain sound image forming acoustic signal based on the frequency domain sound source acoustic signal, the panning information and the arrangement information;
An inverse transform means for Fourier transforming the frequency domain sound image forming sound signal into the sound image forming sound signal that is a time function;
The frequency domain sound image forming acoustic signal generating means,
The sound image forming acoustic signal that forms a sound image acoustic physical quantity vector equal to a sound source acoustic physical quantity vector that is an acoustic physical quantity vector at a sound receiving point when the sound source emitting the sound source acoustic signal is panned based on panning information. A three-dimensional acoustic panning device that generates The panning information input means is
And direction information input means for inputting direction information of the sound source relative to the said sound receiving point,
The three-dimensional sound panning apparatus according to claim 1, further comprising distance information input means for inputting distance information to the sound source based on the sound receiving point. The panning information input means is
The three-dimensional acoustic panning apparatus according to claim 2, further comprising panning information storage means for storing the panning information. The sound image forming acoustic signal output means,
The three-dimensional sound panning apparatus according to any one of claims 1 to 3, further comprising recording / editing means for recording and editing the sound image forming sound signal.

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