JP2924502B2 - Sound image localization control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound image localization control device for controlling a sound image position of a sound to be heard.

[0002]

2. Description of the Related Art Conventionally, in order to realize a sound field effect assuming various performance venues, measurement using a dummy head DH as shown in FIG. 7 has been performed, and acoustic data has been processed based on the measurement. Therefore, there is a method of obtaining a sound image localization equivalent to that of an actual performance hall. The dummy head DH shown in FIG. 7 has a shape similar to a human head, and microphones MR and ML are provided at portions corresponding to the right and left ears.
Is attached.

First, using a dummy head DH shown in FIG. 7, a sound generated from a sound source specified by a horizontal angle ψ, a vertical angle θ, and a distance D (for example, fixed to 1 m) is given to a listener. Capture the waveform when transmitted to the left and right ears of the listener,
Measure the difference from the source sound waveform. This measurement is performed on the sound generated from the sound source at a plurality of positions in the space, and the waveform of the sound generated from the sound source is converted into the waveform when the sound reaches the right or left ear of the dummy head DH from the measured data. (Hereinafter referred to as a head-related transfer function) is calculated according to the position of the sound source.

Next, an FIR filter corresponding to the calculated head related transfer function is created. Then, when the generated acoustic data is processed and reproduced through an FIR filter corresponding to a position to be localized (hereinafter, referred to as a target sound image position), a listener can hear sound from the target sound image position. felt. In order to obtain an FIR filter corresponding to the head-related transfer space, the head-related transfer function may be calculated as described above, or an impulse may be generated from a sound source, and the FIR filter may be generated using the amplitude value of the response waveform as a coefficient. May be created.

As a device based on such a method, a sound image localization control device which gives a sense of distance by controlling a mixing ratio of reverberant sounds and the like has been conventionally developed. FIG. 8 is a block diagram showing a schematic configuration of an example of this type of sound image localization control device.
In this figure, 1 is an input terminal to which sound data is input, 2a and 2b are sound data supplied through the input terminal 1, and a multiplication coefficient 2a supplied from a control unit (not shown).
and 2 minutes based on k and 2bk, a multiplier supplied to the multiplier M ₁ ~M ₁₂ and reverb circuit RV, the sum of the multiplication factor 2ak and 2bk is one. The ratio of the reverberation data to the output acoustic data is small when the target sound image position is at a short distance, and large when the target sound image position is at a long distance.

The reverb circuit RV obtains reverberation data from the acoustic data supplied via the multiplier 2b and adds the R channel component and the L channel component of the reverberation data to an adder 3R.
And 3L. Further, the multipliers M _{1 to} M ₁₂ multiply the acoustic data supplied from the multiplier 2 a based on the multiplication coefficients C _{1 to} C ₁₂ supplied from a control unit (not shown). Dir _{1 to} dir ₁₂ are multipliers M _{1 to} M ₁ , respectively.
A direction assigner that performs a convolution operation based on the head-related transfer function described above on the acoustic data supplied from ₁₂ and outputs the acoustic data of the R / L channel component to the adders 3R and 3L. As shown, two FIRs
The configuration is such that filters are connected in parallel. The FIR filter is a convolution-only LSI or a dedicated DSP
And the coefficient ROM used for the convolution operation is
Generally, they are external.

Here, in order to simplify the explanation, it is assumed that the direction directors dir _{1 to} dir ₁₂ correspond only to the horizontal direction. Directing device dir ₁ is listener in the front direction (horizontal angle 0 ° direction), directing device dir ₂ is a front right 30 ° direction of the listener (horizontal angle 30 ° direction), so that 30
方向 The direction indicator dir ₁₂ is set to the left 3
A convolution operation is performed based on the head related transfer function corresponding to the sound source in the 0 ° direction (horizontal angle 330 ° direction).

In such a configuration, for example, when sound data to be localized at a horizontal angle of 30 ° is supplied to the multipliers 2a and 2b via the input terminal 1, the sound data is output to the multipliers 2a and 2b. subjected multiplication based on the multiplication factor 2ak and 2bk according to the distance of the sound image position is supplied to the multiplier M ₁ ~M ₁₂ and reverb circuit RV. In this case, since the direction in which the sound data is to be localized (hereinafter referred to as the target sound image direction) is the 30 ° horizontal angle, the direction in which the calculation based on the head related transfer function corresponding to the sound source in the 30 ° horizontal angle direction is performed. biasing device dir ₂ is selected by a control unit (not shown). That is, the multiplier only multiplication coefficient C ₂ of M ₂ becomes 1, the other multipliers M ₁ and M ₃ ~M ₁₂
Is 0.

[0009] Multiplier in only directing device dir ₂ which sound data are supplied from the M _2, convolution operation is performed to the supplied sound data, R channel component and the L-channel component of the sound data operation is performed Is supplied to the adders 3R and 3L. On the other hand, it is converted into reverberation data obtained in the reverb circuit RV, and the R channel component and the L channel component of the reverberation data are added to the adders 3R and 3R.
L. Therefore, the final sound data is the sum of the sound data output from the directing device dir _2, the reverberation data output from the reverberation circuit RV.

In order to localize the sound image in the direction of the horizontal angle of 45 °, the multiplication of the multipliers M ₂ and M ₃ connected to the directing devices dir ₂ and dir ₃ corresponding to the directions of the horizontal angles of 30 ° and 60 °. coefficient C ₂ and C ₃ is the ratio of one to one, the other multipliers M ₁ and M ₄ ~M _{1 2} multiplication factor 0. Acoustic data multiplied based on the multiplication factor 2ak in multiplier 2a is, the multiplier when supplied to M ₁ ~M _12, sound data is supplied only to the directing device dir ₂ and dir _3, other fastening directions No sound data is supplied to the vessel. In the directors dir ₂ and dir ₃ the horizontal angle 3
An operation corresponding to the head related transfer functions corresponding to the sound sources in the 0 ° and 60 ° directions is performed, and the R channel component and the L
The acoustic data of the channel component is supplied to adders 3R and 3L.

On the other hand, in the multiplier 2b, the multiplication coefficient 2b
The sound data multiplied on the basis of the k
V, the reverberation data of the R channel component and the L channel component are added to the adders 3R and 3R.
L. Finally, in the adders 3R and 3L, the sound data output from the direction assigners dir2 and dir3 and the reverberation data output from the reverb circuit RV are added to form final sound data.

[0012]

However, in the above-described conventional sound image localization control device, the sense of distance of the sound source is expressed by the mixing ratio of reverberation sounds. Although it was obtained, the sense of distance of the sound source was not so clear. Therefore, if the distance D is not fixed to 1 m and the direction indicator is held not only in the direction but also every predetermined distance,
Although the above disadvantages can be solved, it is necessary to have many directors to cover the required space,
The system becomes huge.

[0011] For example, a sampling frequency of 40 kHz
According to the experiment at 50 kHz, there are at least several hundred stages for expressing the head related transfer function at a predetermined position specified by the direction and the distance, and several thousand stages for expressing in detail. It is necessary to have two FIR filters corresponding to the R / L channel components. Then, the sound image localization control device using the FIR filter is operated in 12 directions (360 °) every 30 ° and 10 directions every 100 mm.
To cover the space up to stage 0 (10 m), 1
100 billion per second (2 × 12 directions × 100 steps × 5000)
(0 Hz) An arithmetic unit having a processing capability of performing multiply and add times is required. The present invention has been made under such a background, and an object of the present invention is to provide a sound image localization control device capable of performing clear sense of distance control in a small-scale configuration.

[0012]

According to the first aspect of the present invention, a plurality of sound image localization data processings for performing data processing for imparting sound image localization feeling corresponding to at least three predetermined directions to input acoustic data. Means, instructing means for instructing the direction and distance of sound image localization, and selectively inputting the sound data to at least one of the plurality of sound image localization data processing means according to the direction instructed by the instructing means. Along with distributing, according to the distance instructed by the instructing means, the input sound data is also distributed to the sound image localization data processing means other than the sound image localization data processing means to which the input acoustic data is distributed according to the direction. Distribution means for distributing data.

Further, in the invention according to claim 2,
Sound image localization data processing means having localization processing data for giving a sound image localization feeling corresponding to a predetermined direction to the input acoustic data, and performing data processing using the localization processing data; and a direction of the sound image localization. And an instructing means for instructing a distance, wherein the sound image localization data processing means performs data processing based on localization processing data corresponding to the direction instructed by the instructing means, and performs the distance instructed by the instructing means. The data processing is performed in consideration of the localization processing data that does not correspond to the instructed direction according to.

[0014]

According to the first aspect of the present invention, when acoustic data is input to the distribution unit, the distribution unit transmits the sound data to at least one of the sound image localization data processing units in accordance with the direction instructed by the instruction unit. The input sound data is selectively distributed, and the sound data is also distributed to sound image localization data processing means other than the sound image localization data processing means according to the distance specified by the instruction means. As a result, in the sound image localization data processing means, the distributed acoustic data is subjected to data processing for imparting a sound image localization feeling corresponding to a predetermined direction.
According to the second aspect of the present invention, when the acoustic data is input to the sound image localization data processing unit, the sound image localization data processing unit performs the localization processing data according to the direction instructed by the instruction unit, and Data processing is performed on the input acoustic data based on the localization processing data that does not correspond to the designated direction.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a sound image localization control device according to one embodiment of the present invention. In FIG. 1, reference numeral 4 denotes a localization controller for setting a target sound image position of a sound. By sliding a knob, a vertical angle slider 4a for setting a vertical angle θ of the target sound image position and a knob are slid. Distance D from target sound image position
Distance slider 4b for setting (for example, 0 to 50 m)
By rotating, the horizontal angle of the target sound image position ψ
(For example, 0-360 °) Direction dial 4c
And

In the localization controller 4, the set vertical angle θ, distance D and horizontal angle ψ are respectively defined by vertical angle instruction data Sθ, distance instruction data SD and horizontal angle instruction data Sψ.
Is transmitted to each connected circuit. 5 is a process for excluding a frequency band corresponding to the vertical angle instruction data Sθ transmitted from the localization controller 4 to audio data supplied from, for example, an electronic device or a sound source device of a video game via the input terminal 1. The notch filter outputs acoustic data localized in the vertical angle θ direction by being applied.

The use of a notch filter to control localization in the vertical direction is described in, for example, Acoustic. Soc. Am. 63 (4), A
pr. 1978 "Psychoacoustical
aspects of synthesizedve
rtical local cubes (Anthon
yJ. Watkins) et al., And will not be described in detail here.

Reference numerals 6a and 6b denote multipliers for multiplying the acoustic data supplied from the notch filter 5 to the common input terminal by multiplication coefficients a and b.
Supplies the multiplication coefficients a and b. 7 determines the multiplication coefficients a and b, and multiplies the multiplication coefficients a and b by the multiplier 6
a and 6b. The multiplication coefficient a of the multiplier 6a increases as the distance D increases in accordance with the distance instruction data SD transmitted from the localization controller 4, as shown in FIG. , And the multiplier coefficient b of the multiplier 6b is determined to be small.

Reference numeral 8n denotes a one-input, twelve-output short-distance distributor that distributes and outputs the acoustic data output from the multiplier 6b, and its schematic configuration is shown in FIG. In FIG. 3, 8
nc, depending on the horizontal angle [psi, determines the multiplication coefficient k ₁ to k _12, is a short-range controller supplies the multiplier 8n ₁ ~8n _12. FIG. 4 shows the relationship between the horizontal angle ψ and the multiplication coefficients k _{1 to} k ₄ and k ₁₂ . In FIG. 4, a multiplication coefficient k _j (2 ≦ j ≦
12) has become what was moved 30 ° parallel to the right in FIG multiplication factor k _j-1, this also applies to the multiplication coefficient k ₅ to k _{1 1} (not shown). As shown in FIG. 4, the short-distance distributor 8n, of the multiplier 8n ₁ ~8n _12,
The number of multipliers whose multiplication coefficients are not 0 is two or less at the same time.

In FIG. 1, reference numeral 8f designates one input 12 for distributing and outputting the acoustic data output from the multiplier 6a.
FIG. 5 shows a schematic configuration of the output long-distance distributor. In FIG. 5, 8Fc in accordance with the horizontal angle [psi, multiplier 8f ₁ determines a multiplication factor m ₁ ~m ₁₂ of ～8F _12, be a long-distance control for supplying to the multipliers 8f ₁ ~8f ₁₂ FIG. 6 shows the relationship between the horizontal angle ψ and the multiplication coefficients m _{1 to} m ₄ and m ₁₂ . In FIG. 6, the multiplication coefficient m _j is obtained by translating the multiplication coefficient m _j-1 by 30 ° to the right in the drawing, and this also applies to the multiplication coefficients m _{5 to} m ₁₁ (not shown). You. As shown in FIG. 6, in the long-distance distributor 8f, among multiplier 8f ₁ ~8f _12, the multiplication coefficient at the same time more than two multipliers positive.

Further, in FIG. 1, FIR _{1 to} FIR
₁₂ is a dir ₁ ~dir ₁₂ and directing device having the same configuration same functions shown in FIG. 8, each performs data processing corresponding to the horizontal angle ψ and the distance D of the object sound image position. In addition, FIG.
In, 9R is directing device FIR ₁ ~FIR one adder for acoustical data addition to the output of the R channel component output from the output end of the _12, 9 L is attached direction units FIR ₁ ~
This is an adder that adds and outputs the acoustic data of the L-channel component output from the other output terminal of the FIR ₁₂ . 10
Is a crosstalk canceller which performs in advance a reverse crosstalk process for canceling a crosstalk component occurring in the reproduction space on the audio data of the R / L channel components output from the adders 9R and 9L. The signal is supplied to left and right speakers (not shown) via the amplifier 11.

In such a configuration, first, the listener operates the vertical angle slider 4a, the distance slider 4b, and the direction dial 4c of the localization controller 4 to thereby obtain the vertical angle θ, the distance D, and the horizontal angle of the target sound image position. Set ψ. Next, when sound data is supplied from the sound generator (not shown) to the notch filter 5 via the input terminal 1, the notch filter 5 supplies vertical angle instruction data Sθ corresponding to the vertical angle θ. , The notch filter 5 processes the sound data according to the vertical angle θ. Thus, the acoustic data for which the localization in the vertical direction has been completed is supplied from the notch filter 5 to the multipliers 6a and 6b.

Further, the controller 7 performs the following based on the distance instruction data SD corresponding to the distance D supplied from the localization controller 4.
Determine the proportion of acoustic data that should be processed for long distance,
Based on the determination, multiplication coefficients a and b are calculated,
It is supplied to multipliers 6a and 6b. Multipliers 6a and 6
In b, the acoustic data supplied from the notch filter 5 is multiplied by the multiplication coefficients a and b supplied from the controller 7, and the long distance distributor 8f and the short distance distributor 8n are multiplied.
Supplied to

In the short distance distributor 8n, the horizontal angle 従 来 of the target sound image position, for example, the horizontal angle 45
In order to perform data processing corresponding to ゜, the supplied acoustic data is provided to the directional control FIR ₂ (ψ = 30 °) and the directional control FIR ₃ (ψ = 60 °) in a one-to-one ratio. as distributed, the multiplication coefficient k ₁ to k ₁₂ multiplier 8n ₁ ~8n ₁₂ is supplied from the controller 7.

Moreover, in the long-distance distributor 8f, for long distance sound source, sound data is supplied, the directing device FIR ₁ 0.1, 0.4 in the directing device FIR ₂ and FIR _3, and so directing device FIR ₄ to 0.1, so as to be distributed also directing device responsible for direction slightly away from the direction of the sound image, the multiplication factor m ₁ ~m ₁₂ multiplier 8f ₁ ~8f ₁₂ is Supplied from the controller 7. In this way, when the target sound image position is at a long distance, by blurring the directional component of the sound image position, a sense of long distance can be given to the sound image.

The sound data distributed by the short distance distributor 8n and the long distance distributor 8f are added with the sound data output from the corresponding multipliers, that is, the short distance and the long distance are interpolated. And the directional devices FIR ₁ to FIR
It is supplied to the IR _12. In the directional devices FIR _{1 to} FIR ₁₂ , first, the acoustic data is separated into R / L channel components, and each is subjected to a set convolution operation. The L channel component of the operated acoustic data is added to an adder 9L.
In addition, the R channel components are added in the adder 9R, and each is supplied to the crosstalk canceller 10.

In the crosstalk canceller 10, R
The sound data of the / L channel component is a component to the left ear of the R signal and a component to the right ear of the L signal generated according to the positional relationship between the two speakers and the listener in the space where the sound is reproduced, that is, Inverse crosstalk processing for canceling crosstalk components is performed, multiplied by the amplifier 11, and output to left and right speakers (not shown). Here, as for the output sound, the farther the target sound image position is, the more the sense of sound image localization becomes blurred. That is, even when the sound source position is at a long distance, a natural sound image localization feeling can be provided.

In the above-described embodiment, the directing device is fixed for each direction to adjust the ratio of the acoustic data distributed to the directing device. The sense of direction may be blurred by using the coefficient set of the function as an average of the coefficient sets corresponding to three or more directions. Also, an example has been described in which the directional devices correspond to twelve directions on the horizontal plane, but any number of directional devices may be used as long as they correspond to three or more directions on the horizontal surface. Further, an example in which the vertical localization is performed using the notch filter 5 has been described.
It is also possible to perform vertical localization using a directing device.

Although the example in which the input acoustic data is one channel has been described, the sound image localization of a plurality of channels can be performed simultaneously by preparing a plurality of similar circuits. Further, since a speaker is used as a device for converting acoustic data into sound, the crosstalk canceller 10 is required. However, the crosstalk canceller 10 is not required for listening with headphones.

[0030]

As described above, according to the present invention,
The sound data input to at least one of the sound image localization data processing means is selectively distributed according to the direction specified by the instruction means, and the sound data is input according to the direction according to the distance specified by the instruction means. By distributing the acoustic data to the sound image localization data processing means other than the sound image localization data processing means to which the extracted data is distributed, there is an effect that clear sense of distance control can be performed with a small-scale configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a sound image localization control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a coefficient supplied from a controller 7 to multipliers 6a and 6b and a distance from a sound source.

FIG. 3 is a block diagram showing a schematic configuration of a short-distance distributor 8n.

FIG. 4 is a diagram showing a relationship between a horizontal angle ψ and multiplication coefficients of multipliers 8n _{1 to} 8n ₁₂ .

FIG. 5 is a block diagram illustrating a schematic configuration of a long-distance distributor 8f.

FIG. 6 is a diagram showing a relationship between a horizontal angle ψ and a multiplication coefficient of multipliers 8f _{1 to} 8f ₁₂ .

FIG. 7 is a diagram for explaining a method of obtaining a head-related transfer function of a direction director using a dummy head DH.

FIG. 8 is a block diagram showing a schematic configuration of an example of a conventional sound image localization control device.

FIG. 9 is a block diagram showing a schematic configuration of direction directors dir _{1 to} dir ₁₂ .

[Explanation of symbols]

4 ...... localization control unit, 7 ...... controller, 8n ...... short distance distributor, 8f ...... long range distributor, FIR ₁ ~ ₁₂ ...... directing device.

Claims (2)

(57) [Claims] 1. A plurality of sound image localization data processing means for performing data processing for imparting sound image localization feeling corresponding to at least three predetermined directions to input acoustic data, and an instruction means for instructing a direction and a distance of sound image localization. And selectively distributing the input acoustic data to at least one of the plurality of sound image localization data processing units according to a direction specified by the indicating unit, and according to a distance specified by the indicating unit. A distribution unit that distributes the input acoustic data also to a sound image localization data processing unit other than the sound image localization data processing unit to which the input acoustic data is distributed according to the direction. Sound image localization control device. 2. A sound image localization data processing means which has localization processing data for imparting a sound image localization feeling corresponding to a predetermined direction to input acoustic data, and performs data processing using the localization processing data. Instruction means for instructing the direction and distance of sound image localization, wherein said sound image localization data processing means performs data processing based on localization processing data corresponding to the direction instructed by said instruction means, and said instruction means A sound image localization control device that performs data processing in consideration of localization processing data that does not correspond to the instructed direction in accordance with the distance instructed by (1).