JP2000250563A - Sound field generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound field space device obtaining a sound field effect when a sound wave emitted from a sound source arrives at a listener through plural sound field space, and the sound field effect in the every moment changed sound field space. SOLUTION: A sound signal supplied from the sound source is performed with sound field processing corresponding to the sound field space characterized by a sound field parameter 1 in a sound field processing unit 201, then, is performed with the sound field processing corresponding to the sound field space characterized by the sound field parameter 2 in the sound field processing unit 202, and finally, is performed with the sound field processing corresponding to the sound field space characterized by the sound field parameter 3 in the sound field processing 203 to be supplied to a sound system amplifying and sound radiating the sound signal. Related to respective sound field parameters supplied to respective sound field processing units, a CPU sets properly along listener operation and an advance of a game program.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound field processing device which is built in or connected to a device for synthesizing or reproducing sounds, such as a game device, an audio device, and a personal computer.

[0002]

2. Description of the Related Art A sound synthesized from a sound source or a sound reproduced from a recording medium is input to a sound field processing device for simulating a real sound field space (for example, a church, a concert hall, a theater, a movie theater). By doing so, a sound field effect is obtained as if the listener were actually in such a sound field space. Such a sound field processing device is commercially available mounted on an AV amplifier, an electronic musical instrument, or a sound card.

FIG. 5 shows a positional relationship between a sound source and a listener in a certain sound field space and a path until the sound pressure emitted by the sound source reaches the listener. In the figure, DR (Dire
(ctRefection) indicates a direct sound component that reaches the listener directly. The direct sound DR has a delay characteristic and a gain characteristic corresponding to the positional relationship between the sound source and the listener. Except for direct sounds, they are collectively called indirect sounds, and include primary reflected sounds, secondary reflected sounds, and so on. Among such indirect sounds, those having a relatively small order are also referred to as initial reflected sounds. ER (Early Reflection)
n) 1-4 indicate primary reflected sound components that reach the listener after being reflected only once on the wall, floor, or ceiling (in the figure, reflections on the floor and ceiling are avoided to avoid complication). Omitted). Each of the primary reflected sounds ER1 to ER4 has a delay characteristic and a gain characteristic corresponding to the positional relationship between the sound source and the listener and the characteristics of the sound field space (such as the shape and material of the room). Although only the direct sound and the primary reflected sound are shown in FIG. 5, a higher-order reflected sound component that reaches the listener after repeating reflection twice, three times,... Is actually added. Of the higher-order reflected sound components, those having relatively higher orders are collectively referred to as rear reverberation sounds.

FIG. 6 shows a so-called impulse response gain obtained by sampling an impulse generated from a sound source position at a listener position in the positional relationship and sound field spatial characteristics shown in FIG. 5, where the horizontal axis represents time and the vertical axis represents time. The axis represents the level. In the figure, DR indicates a direct sound component, which has the highest level and the shortest delay time. ER indicates a primary reflected sound component,
This component has a slightly longer delay time than the direct sound component and is attenuated by walls, floors, etc., and reaches the listener. REV
(Reversion) indicates a higher-order reflected sound component, and this component repeats many reflections with the passage of time and gradually becomes inaudible to human ears. The human ear inputs a complex sound pressure that is a mixture of such direct sound, primary reflected sound and higher-order reflected sound, analyzes it with the brain, and perceives the sound source position and the type of sound field space. I do. In other words, by creating such direct sound, first-order reflected sound and higher-order reflected sound artificially, even when listening in headphones while staying in a specific listening room or my room. This means that the sound field effect is as if you were in a church, concert hall, theater, or movie theater. The sound field processing device, in a nutshell,
Such direct sound, primary reflected sound, and higher-order reflected sound were created.

[0005] In principle, the sound field processing device is realized by simulating an impulse response gain actually measured in an existing famous church, concert hall, theater or the like. However, in consideration of the hardware scale and the amount of calculation, the direct sound and the initial reflected sound having relatively large influence are converted into a multistage delay circuit and a coefficient multiplier for multiplying the output of each tap by a coefficient corresponding to the impulse response gain. It is common to create and simplify the rear reverberation sound having relatively small influence by using an IIR filter.

FIG. 7 is a block diagram of such a sound field processing apparatus, where DL indicates a multi-stage delay circuit, IR indicates an IIR filter, CO indicates a coefficient multiplier, and AD indicates an adder. . Signals extracted from taps of the relatively short delay time of the multi-stage delay circuit DL correspond to direct sound components, and a plurality of signals extracted from taps of the relatively long delay time correspond to initial reflected sound components. I do. II
The signal component extracted from the R filter IR corresponds to the rear reverberation component. A delay parameter for simulating a desired sound field space in such a sound field processing device, IIR
By setting the filter parameters and the coefficient parameters, a desired sound field effect can be obtained. The sound input to the sound field processing device may be a sound synthesized electronically or a sound reproduced from a recording medium.

[0007]

A conventional sound field processing apparatus is known for a famous church, concert hall, theater, movie theater, etc.
Since sound field parameters simulating some typical static sound field spaces are stored, and the listener selects one of the desired sound field spaces, the sound field to be simulated is stored. As the number of spaces increases, the size of the apparatus increases and the cost increases. In addition, the configuration of storing and selecting parameters of a typical sound field space may be sufficient for listening to music, but there is a limit in simulating a sound field space in consideration of various real world situations. . Normally, sound generated in a certain place reaches a human ear via various sound field spaces. Further, the sound source may not always be in a fixed position but may move with time.

For example, as shown in FIG. 8, when a fighter in a hangar at an air force base exits the hangar and jumps out via a runway, when the fighter is in the hangar, the sound pressure is:
The listener reaches the listener via the sound field space of the hangar, runway (outdoor), and room, but with the movement of the sound source (fighter), the elements of the hangar disappear. As described above, the sound field effect when the sound pressure reaches the listener via a plurality of sound field spaces, the sound field effect in a sound field space that changes from moment to moment (dynamically), or the sound source is a sound field space Providing a sound field effect when moving with time within the game is indispensable for improving reality, and is particularly effective in applications such as game machines and virtual experience systems. However, as described above, the conventional sound field processing device only simulates a typical static sound field space.

Further, the conventional sound field processing device can only select any one of such static sound field spaces by the listener, and can combine a plurality of sound field spaces or dynamically change the sound field space. Or to create a new sound field space and obtain a new sound field effect. Therefore, an object of the present invention is to provide a low-cost sound field processing device capable of obtaining a sound field effect when a sound pressure emitted from a sound source reaches a listener via a plurality of sound field spaces. I have. Another object of the present invention is to provide a low-cost sound field processing apparatus capable of obtaining a sound field effect in a sound field space that changes every moment (dynamically). Still another object of the present invention is to provide a low-cost sound field processing device capable of obtaining a sound field effect when a sound source moves with time in a sound field space.

[0010]

In order to achieve the above object, a sound field processing apparatus according to a first aspect of the present invention provides a sound field parameter for simulating a predetermined sound field space by inputting a sound field parameter. A plurality of independent sound field processing units that perform predetermined sound field processing on the sound signal to be processed, and a sound field parameter setting unit that sets independent sound field parameters for each of the plurality of sound field processing units; Coupling means for arbitrarily coupling a plurality of sound field processing units,
A sound signal extracted from a predetermined position of the plurality of sound field processing units combined by the combining means is output as a sound signal subjected to composite sound field processing.

The plurality of sound field processing units respectively generate a direct sound and an indirect sound and synthesize the direct sound and the indirect sound at a predetermined mixing ratio. The parameters of the direct sound and the indirect sound are set for the sound field processing unit, and the mixing ratio of the direct sound and the indirect sound is set.

Further, the sound field parameter setting means includes:
The mixing ratio between the direct sound and the indirect sound of the sound field parameter to be set in at least one sound field processing unit is changed and set according to control information set from the outside. Further, the sound field parameter setting means sets the mixing ratio of the direct sound and the indirect sound of the sound field parameter to be set in at least one sound field processing unit by changing over time.

A sound field processing device according to a second aspect of the present invention performs predetermined sound field processing on an input sound signal by setting sound field parameters for simulating a predetermined sound field space. A plurality of sound field processing units cascaded with each other, and sound field parameter setting means for setting independent sound field parameters for each of the plurality of sound field processing units; The output of the sound field processing unit at the last stage of the processing unit is output as a sound signal that has been subjected to composite sound field processing.

Further, the plurality of sound field processing units generate a direct sound and an indirect sound, respectively, and synthesize the direct sound and the indirect sound at a predetermined mixture ratio.
The sound field parameter setting means sets the parameters of the direct sound and the indirect sound and sets the mixing ratio of the direct sound and the indirect sound for each of the sound field processing units.

Further, the sound field parameter setting means includes:
The mixing ratio between the direct sound and the indirect sound of the sound field parameter to be set in at least one sound field processing unit is changed and set according to control information set from the outside.

Further, the sound field parameter setting means includes:
The mixing ratio between the direct sound and the indirect sound of the sound field parameter to be set in at least one sound field processing unit is set by changing over time.

A sound field processing apparatus according to a third aspect of the present invention provides a sound field for performing a predetermined sound field process on an input sound signal by setting a sound field parameter for simulating a predetermined sound field space. A processing unit, sound field parameter generating means for generating a plurality of sound field parameters for simulating a plurality of different sound field spaces, and synthesizing a plurality of sound field parameters generated by the sound field parameter generating means. Sound field parameter synthesizing means for generating a composite sound field parameter; and sound field parameter setting means for setting the composite sound field parameter synthesized by the sound field parameter synthesizing unit to the sound field processing unit. The output of the processing unit is output as a sound signal that has been subjected to the complex sound field processing.

The sound field processing unit comprises a multi-stage delay means and a plurality of coefficient multiplying means for multiplying the output of each stage by a predetermined coefficient. The sound field parameter generating means comprises a plurality of sound field parameter generating means. Parameters are respectively generated as impulse response gains, and the sound field parameter synthesizing means generates a composite impulse response gain by convolving a plurality of impulse response gains corresponding to a plurality of sound field parameters. The sound field parameter setting means sets coefficients of a plurality of coefficient multiplying means of the sound field processing unit according to the composite impulse response gain.

Further, when the sound field parameter synthesizing means convolves a plurality of impulse response gains to generate a composite impulse response, if each impulse response gain is equal to or less than a predetermined threshold value, it is regarded as 0. I do.

The sound field processing unit includes a direct sound / initial reflected sound generating means and a II which comprises a multi-stage delay means and a plurality of coefficient multiplying means for multiplying the output of each stage by a predetermined coefficient.
The sound field parameter generating means includes an impulse response gain for setting a plurality of sound field parameters in the direct sound / early reflected sound generating means and the rear reverberation. The sound field parameter synthesizing means generates a composite impulse response gain by convolving a plurality of the impulse response gains, wherein the sound field parameter synthesizing means generates a composite impulse response gain. The parameter setting means sets coefficients of a plurality of coefficient multiplying means of the sound field processing unit according to the composite impulse response gain.

Further, the sound field parameter synthesizing means selects a predetermined one of a plurality of IIR filter parameters and generates it as a composite IIR filter parameter.
The filter parameter is set in the IIR filter of the sound field processing unit.

Further, the sound field parameter synthesizing means generates an average value of a plurality of IIR filter parameters as a composite IIR filter parameter, and the sound field parameter setting means converts the composite IIR filter parameter into the sound field processing unit. Is set in the IIR filter.

Further, the sound field parameter synthesizing means includes means for converting each of the plurality of IIR filter parameters into an impulse response gain.

Further, the sound field parameter generating means generates the sound field parameter by changing at least one of the plurality of sound field parameters in accordance with control information set from outside.

Further, the sound field parameter generating means generates at least one of a plurality of sound field parameters by changing over time.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of the embodiments, the relationships among direct sound, indirect sound, primary reflected sound, initial reflected sound, higher-order reflected sound, and rear reverberant sound are also arranged for the purpose of organizing the meaning of terms. Keep it. The direct sound indicates a component that reaches a listener's ear directly without reflection, and the indirect sound indicates a component other than the direct sound, that is, a primary reflected sound, an initial reflected sound, a higher reflected sound, a rear reverberant sound. Is included. The primary reflected sound indicates a component that reaches the listener's ear after being reflected by a wall or the like only once, and the initial reflected sound indicates a relatively low-order reflected sound component including the primary reflected sound. The reflected sound indicates a reflected sound component other than the primary reflected sound. Further, the rear reverberation sound indicates a reflection sound component having a relatively large order in the higher-order reflection sound.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a hardware configuration of a game machine to which the present invention is applied. In the figure, 10
Reference numeral 1 denotes a CPU (Central Processing Unit) that controls each unit according to a program, graphics data, sound data, and the like downloaded from a CD-ROM (not shown) mounted on the CD-ROM drive 102 to the memory 103. The CPU, the sound control program and the sound data stored in the CD-ROM constitute a part of the present invention.

Reference numeral 103 denotes a memory configured by a ROM unit that stores default programs, data, and the like, and a RAM unit that is also used as a work area of the CPU 101 in addition to storing data downloaded from the CD-ROM. Reference numeral 104 denotes an input unit which is operated by the user in accordance with the progress of the game and includes push buttons, a keyboard, and the like. The operation status is detected by the CPU 101, and the game story, graphics, and Sound is controlled. The graphics system is not shown because it is not directly related to the present invention.

Reference numeral 105 denotes a sound unit, and a sound source 106,
It comprises a sound field processing device 107 and a sound system 108. The sound source 106 generates a musical sound, voice, and music (hereinafter, collectively referred to as a “sound signal”) under the control of the CPU 101. As the tone / speech synthesis form, F
Arbitrary forms such as M (frequency modulation) type synthesis, wavetable type synthesis, physical model simulation type synthesis, and formant sinking type synthesis are possible. The synthesis of such musical tones is performed by the CPU 101 decoding the MIDI sound data downloaded from the CD-ROM to the memory 103 along with the progress of the game, and setting specific sound parameters to the sound source 106. Will be Also, under the control of the CPU 101, the sound source 106 can directly input music data (wave data) such as BGM stored in a CD-ROM, and output the music data as it is or at a different playback speed. .

Under the control of the CPU 101, the sound field processing device 107 performs sound field processing for imparting a sound field effect to the sound signal supplied from the sound source 106. The contents of the sound field processing follow the contents of the sound field parameters supplied from the CPU 101 according to the sound control program downloaded from the CD-ROM to the memory 103. The sound field parameters corresponding to a plurality of different sound field spaces have been downloaded from the CD-ROM to the memory 103 in advance. The sound field parameters corresponding to a plurality of sound field spaces may be prepared by the game creator in consideration of the character of the game, but examples include churches, concert halls, movie theaters, rooms, high-rise buildings, gymnasiums. , Warehouse, sea, mountain, flatland, city, countryside, ground, sky, sea, underwater, space, etc. The sound field processing device 107 forms a part of the present invention.

The sound system 108 amplifies and emits a sound signal to which a sound field effect is supplied from the sound field processing device 107 as appropriate. The above is an outline of the hardware configuration of the game machine to which the present invention is applied. Here, the concept of the composite sound field processing performed by the sound field processing device 107 will be described once leaving the drawing. First, we
In the real world, we focused on the fact that sound waves generated at a certain place reach the listener's ear via various sound field spaces. The number of sound field spaces that pass through increases as the sound source position is farther from the listener. Since existing sound field processing devices merely simulate a single closed sound field space, reality is high in applications such as game machines where the sound source position changes interactively and dynamically. I discovered that it was causing the chipping. That is, the fact that the sound source position changes means that the sound field space interposed between the sound source position and the listener changes, but this is not considered at all.

Therefore, we have introduced the concept of "complex sound field space" and "composite sound field processing". The concept is as follows. "The transfer function of each sound field space is S
0, S1, S2, S3,..., Sn,
When sound waves emitted by a sound source are transmitted through the plurality of sound field spaces, the composite transfer function is a linear combination of transfer functions of the respective sound field spaces. "The impulse response gains of the plurality of sound field spaces are H0, H1, H
2, H3,..., Hn, and the sound waves emitted by the sound source are transmitted through the plurality of sound field spaces,
The composite impulse response gain is a convolution of the impulse response gain of each sound field space. "

Next, the contents of the processing performed by the sound field processing device 107 in order to realize the concept of the complex sound field processing will be described in detail. FIG. 2 is a block diagram showing a first embodiment of the sound field processing device 107. In this embodiment, the sound field processing device includes a plurality of cascade-connected sound field processing units 201, 202, and 203. Each sound field processing unit has the same hardware configuration, for example, as shown in FIG. In each sound field processing unit, sound field parameters corresponding to different sound field spaces are set by the CPU 101 by the operation of the listener or along with the progress of the game program. The sound signal supplied from the sound source 106 is first subjected to sound field processing corresponding to the sound field space characterized by the sound field parameter 1 in the sound field processing unit 201, and then to the sound field processing unit 202. The sound field processing corresponding to the sound field space characterized by the parameter 2 is performed, and finally the sound field processing corresponding to the sound field space characterized by the sound field parameter 3 is performed by the sound field processing unit 203. Provided to system 108. In the first embodiment, complex sound field processing is realized by cascading a plurality of sound field processing units. Regarding the sound field parameters to be supplied to the plurality of sound field processing units, C is set by the operation of the listener or along with the progress of the game program.
The PU 101 sets as appropriate.

Although the connection form of the plurality of sound field processing units is a fixed cascade connection in this embodiment, the connection form may be changed in a programmable manner. Further, when the sound field parameter changes with the movement of the sound source, a more realistic sound field effect can be obtained by introducing the crossfade method. The following two embodiments can be considered for introducing the crossfade method.

(1) Cross-Fade Synthesis of Sound Field Parameters When sound field processing of a certain sound field processing unit is switched off, the supplied sound signal should be gradually switched to a sound field parameter that directly outputs the supplied sound signal as it is. When changing to another sound field parameter, the old sound field parameter whose weight gradually decreases and the new sound field parameter whose weight gradually increases become weighted and added, and the sound field parameter is set. I just need. In the case of this cross-fade method, the CP in FIG.
U101 is performed by setting the sound field parameters while performing the cross-fade calculation.

(2) Crossfade Synthesis of Sound Field Processing Unit The crossfade method can be realized even if the sound field processing device 107 is configured as shown in FIG. In the figure, 304, 305
Denotes sound field processing units, each of which is configured as shown in FIG. Reference numerals 306 and 307 denote coefficient multipliers,
308 indicates an adder. With this configuration, when the sound field processing is switched off in a state where predetermined sound field parameters are set in the sound field processing unit 304 as an initial state, a sound signal is output to the sound field processing unit 305 through. After setting such sound field parameters, the coefficient of the coefficient multiplier 306 may be gradually changed from 1 to 0, and the coefficient of the coefficient multiplier 307 may be gradually changed from 0 to 1. When changing the sound field parameter set in the sound field processing unit 304 to another sound field parameter, the changed sound field parameter is set in the sound field processing unit 305, and then the coefficient multiplier 3
The coefficient of the coefficient multiplier 307 may be gradually changed from 0 to 1 while the coefficient of 06 is gradually changed from 1 to 0.

As a simplified method for simulating the movement of the sound source, a method of changing only the coefficient parameter given to the coefficient multiplier CO of the sound field processing device shown in FIG. 7 is also effective. In this case, the ratio between a coefficient parameter to be multiplied by a signal extracted from a tap position corresponding to a direct sound of the multi-stage delay circuit DL and another coefficient parameter may be changed. That is, when the sound field processing of a certain sound field processing unit is switched off, the coefficient parameter for multiplying the direct sound is gradually switched toward 1, and the other coefficient parameters are gradually switched toward 0. Good.

In a case where a listener inside the building hears a sound when a fighter waiting in the hangar jumps out, as illustrated in FIG. 8, the sound field parameter 1 corresponding to the hangar is the sound field processing unit. 201, the sound field parameter 2 corresponding to the outdoor (runway) is set to the sound field processing unit 2
02, the sound field parameter 3 corresponding to the room in the building is set in the sound field processing unit 203,
The sound source generates engine sounds of a fighter, a frictional sound of tires rubbing the ground, and a wind noise generated by friction between wings and air. Then, as time elapses, as the fighter moves from the hangar to the runway, the sound field parameter 1 of the sound field processing unit 201 is changed to a sound field parameter corresponding to the sound field processing off, and when the fighter further takes off. The sound field parameter 2 corresponding to the outdoor (runway) is changed to the sound field parameter corresponding to the outdoor (the sky). As described above, the compound sound field processing corresponding to the hangar, the outdoor (runway) and the room is realized, and the sound field space can be dynamically changed in accordance with the passage of time or the progress of the game program.

FIG. 4 is a block diagram showing a second embodiment of the sound field processing device 107. In the first embodiment, the composite sound field processing is realized by connecting a plurality of sound field processing units having the same hardware configuration. However, in the second embodiment, a single sound field processing unit is It is characterized in that a composite sound field parameter created by calculation in advance is set. With this configuration, hardware costs can be reduced. A sound field parameter corresponding to a predetermined sound field space can be expressed as an impulse response gain obtained by sampling an impulse generated at a predetermined position in the sound field space. Then, by having the impulse response gain as a sound field parameter and setting the impulse response gain as a tap coefficient of the FIR filter, sound field processing can be realized.

FIG. 4 shows a hardware configuration of a sound field processing unit in a case where sound field processing is realized by using the sound field parameters as impulse response gains as described above. In the drawing, reference numerals 401 to 40n denote delay elements, which delay an input signal by a time corresponding to one sampling cycle and output the delayed signal. Reference numerals 411 to 41n denote coefficient multipliers.
The signal of each tap (delay time is different) indicated by ● is separately multiplied by a coefficient corresponding to an impulse response gain which is a sound field parameter corresponding to a predetermined sound field space, and is output. An adder 420 adds the outputs of the respective coefficient multipliers and outputs a signal subjected to sound field processing.

Next, a method of creating a composite sound field parameter to be set in such a sound field processing unit will be described. The creation of the composite sound field parameters is performed by the CPU 101. When a sound field parameter is provided as an impulse response gain H, the impulse response gains as sound field parameters respectively corresponding to the two sound field spaces are H ₁ = (x1, x2, x3,..., Xn) H ₂ = (Y1, y2, y3,..., Yn), the composite impulse response gain H _RESULT as a composite sound field parameter can be derived by the following equation. H _RESULT = (x1 · y1, x2 · y1 + x1
· Y2, x3 · y1 + x2 · y2 + x1 · y3, ..., x
n · yn) By setting each term of the composite impulse response gain H _{RESULT in} the coefficient multipliers 411 to 41n, a sound field effect corresponding to a desired composite sound field space can be obtained.
The above example is an example of calculating composite sound field parameters corresponding to two sound field spaces. However, composite sound field parameters corresponding to three or four sound field spaces can be calculated in the same manner.

In the above-described method of creating the composite sound field parameters, all the terms of the composite impulse response gain are regarded as significant information and the convolution operation is performed one by one. However, a predetermined threshold is provided, and terms below the threshold are regarded as 0. Thus, the operation can be simplified. Further, according to the above-described creation method, the number of terms of the composite impulse response gain corresponding to the composite sound field space is inevitably increased with respect to the impulse response gain corresponding to each sound field space. Can be deleted. The calculation can also be simplified by such a contrivance. Even if such a simplification method is applied, the effect of the sound field effect is small.

It should be noted that also in the second embodiment, the first
By using the cross-fade method (1), a realistic sound field effect in which the sound field parameter changes with the movement of the sound source can be obtained as in the embodiment. However, a little contrivance is required to remove a certain sound field space. In other words, when a certain sound field space is removed, if all the terms of the impulse response gain corresponding to the sound field space are simply gradually changed toward 0, the convolution result of the composite impulse response gain All terms become 0. In order to eliminate such inconvenience, it is preferable to gradually switch to (1, 0, 0,..., 0) instead of gradually switching to all 0s.

Next, a third embodiment of the sound field processing device 107 will be described. This third embodiment is common to the second embodiment in that a composite sound field parameter created by performing a calculation in advance for a single sound field processing unit is set, but each sound field space Have different sound field parameters corresponding to. That is, in the second embodiment, the sound field parameter is provided in the form of an impulse response gain.
To create high-order reflections with such a configuration with high accuracy,
A multi-stage delay circuit having an enormous number of taps and a coefficient multiplier are required, and an increase in cost is inevitable. In the third embodiment, a sound field parameter is provided as an impulse response gain + IIR filter parameter. The impulse response gain is a parameter mainly corresponding to the early reflection sound, and the IIR filter parameter is a parameter mainly corresponding to the rear reverberation sound. By having the sound field parameters in such a form, the capacity of the memory for storing the sound field parameters corresponding to each sound field space can be reduced.

The block diagram of the sound field processing device 107 corresponding to the third embodiment is the same as that shown in FIG. However, parameters (impulse response gain) to be given to the multi-stage delay circuit and parameters to be given to the IIR filter IR are determined by the CPU 101.
Is a parameter corresponding to the complex sound field space calculated in advance. As for the impulse response gain, a composite impulse response gain is obtained by performing a convolution operation of the impulse response gain corresponding to each sound field space, as in the second embodiment. Requires some ingenuity. In the first place, the attempt to realize the rear reverberation with an IIR filter itself,
This indicates that the effect on the auditory perception of the rear reverberation is neglected as compared to the early reflections. However, the rear reverberation created by such an IIR filter has the following characteristics.
Even if the sound field space changes, it does not change much. That is,
It becomes a noise-like sound signal with a small level.

Based on such considerations, a method of creating some composite IIR filter parameters will be described below. (1) Select an arbitrary one By selecting one according to a predetermined rule from IIR filter parameters corresponding to a plurality of sound field spaces, a composite IIR filter parameter can be obtained. Regarding which IIR filter parameter is selected, the attenuation coefficient or the delay time in each IIR filter parameter is compared, and the I / F in which the reverberation sound continues to be generated for the longest time is determined.
It would be good to select IR filter parameters.

(2) Averaging The average value of a plurality of IIR filter parameters is calculated as a composite IIR
It can also be a filter parameter. (3) Parallel Installation Although the purpose is not to create a composite IIR filter parameter, a plurality of IIR filters having IIR filter parameters corresponding to each sound field space may be installed in parallel. In this case, the IIR filter IR in FIG. 7 includes a plurality of parallel IIR filter units.

(4) Conversion of IIR filter parameters to impulse response gains This also departs from the purpose of creating composite IIR filter parameters, but the output when an impulse is input to an IIR filter corresponding to a predetermined IIR filter parameter. After calculating the (Impulse response gain), the IIR filter parameter is converted into the impulse response gain, and then combined with the impulse response gain corresponding to the initial reflected sound, and the impulse response gain is calculated in the same manner as in the second embodiment. A method of performing convolution operation on each other is also conceivable.

[0049]

As described above, according to the sound field processing apparatus of the present invention, the sound field effect when the sound pressure reaches the listener via a plurality of sound field spaces at a low cost, from moment to moment. Sound field effect in the sound field space that changes (dynamically)
Alternatively, it is possible to provide a sound field effect when the sound source moves with time in the sound field space.

Further, according to the sound field processing apparatus of the present invention, a new sound field space is created by combining a plurality of sound field spaces or dynamically changing the sound field space at a low cost. It is possible to obtain a great sound field effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a game machine to which the present invention is applied.

FIG. 2 is a block diagram showing an embodiment of a sound field processing device of the present invention.

FIG. 3 is a block diagram showing an embodiment of a sound field processing device of the present invention.

FIG. 4 is a block diagram showing an embodiment of a sound field processing device of the present invention.

FIG. 5 is a diagram illustrating a positional relationship between a sound source and a listener in a listening room and a sound pressure propagation path from the sound source to the listener.

FIG. 6 is a diagram illustrating characteristics of a direct sound, a first-order reflected sound, and a higher-order reflected sound.

FIG. 7 is a block diagram showing a configuration of a conventional sound field processing device.

FIG. 8 is a diagram showing an example of a composite sound field space.

[Explanation of symbols]

101: CPU, 102: CD-ROM drive, 103: Memory, 104: Input unit, 105
... Sound part, 106 ... Sound source, 107 ... Sound field processing device, 108 ... Sound system, 201,
202, 203 ... sound source processing unit, 304, 30
5 ... sound field processing unit, 306, 307 ... coefficient multiplier, 308 ... adder, 401, 402, ..., 4
0n delay elements, 411, 412, ..., 41n ...
Coefficient multiplier, 420 ... adder

Claims (17)

[Claims] A plurality of independent sound field processing units for performing predetermined sound field processing on an input sound signal by setting sound field parameters for simulating a predetermined sound field space, respectively. A sound field parameter setting unit that sets independent sound field parameters for each of the plurality of sound field processing units; and a coupling unit that arbitrarily couples the plurality of sound field processing units. A sound field processing device, which outputs sound signals extracted from predetermined positions of a plurality of sound field processing units as sound signals subjected to composite sound field processing. 2. The sound field processing unit according to claim 1, wherein the plurality of sound field processing units respectively generate a direct sound and an indirect sound and synthesize the direct sound and the indirect sound at a predetermined mixing ratio. 2. The sound field processing apparatus according to claim 1, wherein parameters of the direct sound and the indirect sound are set for the sound field processing unit, and a mixing ratio of the direct sound and the indirect sound is set. 3. The sound field parameter setting means changes a mixing ratio of a direct sound and an indirect sound of a sound field parameter to be set in at least one sound field processing unit according to control information set from outside. The sound field processing device according to claim 2, wherein the sound field processing device is set. 4. The sound field parameter setting means sets a mixing ratio of a direct sound and an indirect sound of a sound field parameter to be set in at least one sound field processing unit by changing over time. The sound field processing device according to claim 2. 5. A plurality of cascaded sound fields for performing predetermined sound field processing on an input sound signal by setting sound field parameters for simulating a predetermined sound field space, respectively. A processing unit, and sound field parameter setting means for setting independent sound field parameters for each of the plurality of sound field processing units, and a final stage sound field processing of the plurality of cascade-connected sound field processing units. A sound field processing device for outputting an output of a unit as a sound signal subjected to a complex sound field process. 6. The plurality of sound field processing units respectively generate a direct sound and an indirect sound and synthesize the direct sound and the indirect sound at a predetermined mixture ratio. 6. The sound field processing apparatus according to claim 5, wherein parameters of the direct sound and the indirect sound are set for the sound field processing unit, and a mixing ratio of the direct sound and the indirect sound is set. 7. The sound field parameter setting means changes a mixing ratio of a direct sound and an indirect sound of a sound field parameter to be set in at least one sound field processing unit according to control information set from outside. The sound field processing device according to claim 6, wherein the sound field processing device is set. 8. The sound field parameter setting means sets a mixing ratio of a direct sound and an indirect sound of a sound field parameter to be set in at least one sound field processing unit by changing over time. The sound field processing device according to claim 6. 9. A sound field processing unit for performing predetermined sound field processing on a sound signal inputted by setting sound field parameters for simulating a predetermined sound field space, and a plurality of different sound sources. Sound field parameter generating means for generating a plurality of sound field parameters for simulating a field space; and a sound field for generating a composite sound field parameter by combining the plurality of sound field parameters generated by the sound field parameter generating means. Parameter synthesis means, and sound field parameter setting means for setting the composite sound field parameters synthesized by the sound field parameter synthesis means to the sound field processing unit, wherein the output of the sound field processing unit is a complex sound field. A sound field processing device for outputting a processed sound signal. 10. The sound field processing unit comprises a multi-stage delay means and a plurality of coefficient multiplying means for multiplying the output of each stage by a predetermined coefficient, wherein the sound field parameter generating means comprises a plurality of sound field parameter generating means. Parameters are respectively generated as impulse response gains, and the sound field parameter synthesizing means generates a composite impulse response gain by convolving a plurality of impulse response gains corresponding to a plurality of sound field parameters. 10. The sound field processing apparatus according to claim 9, wherein the sound field parameter setting means sets coefficients of a plurality of coefficient multiplying means of the sound field processing unit according to the composite impulse response gain. 11. The direct sound / initial reflected sound generating means and IIR comprising a multi-stage delay means and a plurality of coefficient multiplying means for multiplying the output of each stage by a predetermined coefficient.
The sound field parameter generating means includes an impulse response gain for setting a plurality of sound field parameters in the direct sound / early reflected sound generating means and the rear reverberant sound. The sound field parameter synthesizing means generates a composite impulse response gain by convolving a plurality of the impulse response gains, wherein the sound field parameter synthesizing means generates a composite impulse response gain. The sound field processing apparatus according to claim 9, wherein the setting means sets coefficients of a plurality of coefficient multiplying means of the sound field processing unit according to the composite impulse response gain. 12. The sound field parameter synthesizing means selects a predetermined one of a plurality of IIR filter parameters to generate a composite IIR filter parameter, and the sound field parameter setting means generates the composite IIR filter parameter. Is set in the IIR filter of the sound field processing unit. 13. The sound field parameter synthesizing means generates an average value of a plurality of IIR filter parameters as a composite IIR filter parameter, and the sound field parameter setting means converts the composite IIR filter parameter into the sound field processing unit. The sound field processing device according to claim 11, wherein the sound field processing device is set in the IIR filter of (1). 14. The apparatus according to claim 11, wherein said sound field parameter synthesizing means includes means for converting a plurality of IIR filter parameters into respective impulse response gains.
The sound field processing device according to claim 1. 15. When generating a composite impulse response by convolving a plurality of impulse response gains with each other, the sound field parameter synthesizing unit considers each impulse response gain to be 0 when the gain is equal to or less than a predetermined threshold. The sound field processing device according to claim 10. 16. The sound field according to claim 9, wherein said sound field parameter generating means changes at least one of a plurality of sound field parameters according to control information set from outside. Processing equipment. 17. The sound field processing device according to claim 9, wherein said sound field parameter generating means generates at least one of a plurality of sound field parameters by changing over time.