JPH06133400A - Localization sound image generator - Google Patents

Abstract

PURPOSE:To obtain a localization sound image with high quality and inexpensive and small scale of circuit configuration. CONSTITUTION:Seven series of waveform data read from a waveform memory 1' are fed to a demultiplexer 3, from which the data are respectively given to multipliers 4a-4g. The supplied 7 series of waveform data are multiplied with multiplication coefficients GA-GG in response to a vertical angle theta supplied from a controller 2 at the multipliers 4a-4g, the results are added by an adder 5 and one waveform data are obtained. Then a reverberation tone is generated in a l' in response to a distance D from the added waveform data at multipliers 6a, 6b, and a delay time difference and an amplitude difference are given to an R-channel component and an L-channel component in response to a horizontal angle psi at multipliers 8a, 8b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a localized sound image generating apparatus for generating a sound image localized at a predetermined position in space.

[0002]

2. Description of the Related Art In a conventional sound image localization device for locating a sound image at a predetermined position, there is known a technique for locating a sound image using a head related transfer function representing a sound field. This technique will be described below. First, how the sound generated from the sound source at a predetermined position in space is transmitted to the listener, that is,
Measure the head related transfer function. For this measurement, a so-called impulse response method in which an impulse generated from a sound source at a predetermined position is captured by a small microphone installed in the listener's right and left ears is suitable.

An FIR filter having each amplitude value of the measured impulse response waveform as a coefficient is prepared, and a directional device for performing convolution calculation of sound image localization is manufactured by using this as a pair on the left and right sides. A convolution operation is performed on the waveform data thus obtained. Next, by listening to the waveform data that has been subjected to the convolution calculation independently by using headphones or earphones, the listener can obtain the feeling that the sound image of the sound being heard is localized at a predetermined position. You can

[0004]

By the way, in the above-mentioned conventional sound image localization apparatus, the directional device for performing the convolution operation is composed of the FIR filter, but this FIR filter requires enormous processing (several hundred times). ~ Thousands of multiplications)
Since it is necessary to use an expensive circuit capable of instantaneously (for example, one sampling clock is 20 μs or less), this is one of the factors that increase the manufacturing cost.

Further, in the above-described sound image localization apparatus, in order to obtain a sufficiently clear localization feeling, it is necessary to dispose the directing devices densely corresponding to the positions where the space that can be the sound source position is sufficiently subdivided. For this reason, the circuit scale tends to be huge. The present invention has been made in view of such a background, and provides a localization sound image generation device which has an inexpensive and small-scale circuit configuration and is capable of realizing a high-quality localization feeling and a moving feeling of a sound image. With the goal.

[0006]

According to a first aspect of the present invention, there is provided a localization sound image generating apparatus according to a first aspect of the invention. It is characterized by comprising: designating means and waveform data generating means for reading the waveform data from the storage means and selectively generating the waveform data corresponding to the position designated by the position designating means. There is.

The localization sound image generating apparatus according to a second aspect of the invention is a storage means for storing a plurality of waveform data corresponding to a plurality of predetermined discrete positions in space, and a position specifying means for specifying the position in the space. And a means for reading out waveform data from the storage means, and a weighting addition means for performing weighted addition to the waveform data read out according to the position designated by the position designating means.

The localization sound image generating apparatus according to a third aspect of the present invention is a storage means for storing a plurality of waveform data corresponding to a plurality of positions in the vertical direction of the space, and a position designating means for designating the position of the space. Waveform data generation means for reading waveform data from the storage means, the waveform data generation means selectively generating waveform data in accordance with a vertical component of a position designated by the position designation means, and the position designation A conversion means for applying a delay time difference and an amplitude difference to the right channel component and the left channel component of the waveform data generated by the waveform data generation means according to the horizontal angle direction component of the position designated by the means. Is characterized by.

[0009]

According to the structure described in claim 1, the waveform data corresponding to the position designated by the instructing means is selected by the waveform data generating means from the plurality of waveform data stored in the storing means, and is output. It According to the configuration of claim 2, in the weighting addition means, the plurality of waveform data read from the storage means are weighted and added in accordance with the position designated by the instruction means, thereby being dispersed. Waveform data corresponding to the positions between the positions are obtained.

According to the third aspect of the invention, from the plurality of waveform data stored in the storage means corresponding to the vertical direction, the vertical direction component of the position designated by the indicating means is corresponded. The waveform data is selected by the waveform data generating means. Next, in the converting means, the delay time difference and the amplitude difference are given to the right channel component and the left channel component of the selected waveform data according to the component in the horizontal angle direction of the designated position.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A localization sound image generating apparatus according to an embodiment of the present invention stores waveform data of a plurality of sample waveforms corresponding to a vertical angle .theta. Since the sense of localization in the horizontal angle ψ direction can be sufficiently expressed by the amplitude difference and the delay time difference of the R / L channel components of the waveform data, the sample waveform corresponds only to the vertical angle θ. First, the process of collecting the waveform data of the sample waveform will be described with reference to FIG.

In FIG. 5, the horizontal angle ψ from the origin O and
It is assumed that the sound source P specified by the vertical angle θ and the distance D exists on the spherical surface S having the origin O as the center point and the radius r (r = D). DH is a dummy head having a shape imitating a human head placed with its center aligned with the origin O, and microphones for collecting the sound generated from the sound source P are provided in the portions corresponding to the right and left ears. MR and ML are attached.

The points A to G are points on the line of intersection of the spherical surface S and the plane specified by the origin O and the front and vertical directions of the dummy head DH, and are arranged at equal intervals.
The vertical angle θ with respect to the point A is 0 °, the vertical angle θ with respect to the point B is 30 °, and the points are arranged at intervals of 30 °.
The vertical angle θ with respect to is 180 °. Reference numeral 1 is a waveform memory that stores waveform data of sounds collected by the microphones MR and ML.

In such a structure, when a sound source P arranged on one of the points A to G plays a predetermined musical instrument, for example, a trumpet to generate a sound, the generated sound propagates in the air, Dummy head DH microphones MR and M
It is sampled in L and converted into an electric signal. When this electric signal is subjected to A / D conversion by an A / D converter (not shown), the electric signal is converted into digital data and stored in the waveform memory 1. That is, although all waveforms are sampled, the longer the sampling time, the better (of course, the length is less than the memory capacity limit). Here, the same sound is generated for each of the points A to G, and sampling is performed for about 3 seconds. As described above, the process of collecting the waveform data of the sample waveform is completed as described above.

Next, an embodiment of the present invention based on the waveform memory 1 created through the above process will be described with reference to the drawings. 1 is a block diagram showing a configuration of a localization sound image generating apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1'denotes a waveform memory which stores the same waveform data as the waveform memory 1, and is not shown. The waveform data of the tone color corresponding to the tone color data ST supplied from the keyboard or the like is output. Here, the output waveform data is 7 series of waveform data corresponding to points A to G.

Reference numeral 2 denotes a localization control device for setting a position at which a sound image should be localized (hereinafter referred to as a target sound image position). As shown in FIG. 2, the localization control device is composed of an instruction section 2a and a control section 2b. There is. Further, the pointing portion 2a is rotated to specify a vertical angle, and thus the vertical angle dial 2a is used.
₁ , a horizontal angle dial 2a ₂ for designating a horizontal angle by rotating, and a distance slider 2a ₃ for designating a distance by sliding a knob. Then, the vertical angle θ, the horizontal angle ψ, and the distance D that specify the target sound image position are supplied to the control unit 2b.

In this embodiment, since the points A to G correspond to the upper hemisphere, the vertical dial 2a ₁ is set to be freely rotatable in the range of 0 ° to 180 °. In addition,
When sound is generated and sampled at a position below the dummy head DH, that is, when the whole ball is used, the rotation is set freely in the range of 0 ° to 360 °, that is, any number of revolutions. Further, the horizontal angle dial 2a ₂ is freely rotatable in the range of 0 ° to 360 °.

In 3 of the waveform memory 1 ', 7 series of waveform data corresponding to points A to G are read out as a series of data (serial data) by time division processing, and 7 series of independent waveform data ( a demultiplexer for converting into parallel data), 4a-4g is the waveform data outputted from the demultiplexer 3, respectively, a multiplier for multiplying the corresponding multiplication coefficient G _a ~G _G, multiplication coefficient G _a ~G
_G is a control unit 2b of the localization control device 2 as shown in FIG.
It is controlled according to the vertical angle θ supplied from.

Next, 5 is an adder for adding 7 series of waveform data output from the multipliers 4a to 4g and outputting one waveform data, and 6a and 6b are as shown in FIG.
The multiplier 7 multiplies the waveform data output from the adder 5 by the multiplication coefficients a and b according to the distance D supplied from the control unit 2b. Reference numeral 7 represents the waveform data output from the multiplier 6a.
A delay unit that separates the / L channel component and delays each. Next, 8a and 8b are multipliers for multiplying the waveform data of the R channel component and the L channel component output from the delay unit 7 by the multiplication coefficients c and d according to the horizontal angle ψ supplied from the control unit 2b. is there.

Next, reference numeral 9 is a reverberation generator for separating the waveform data output from the multiplier 6b into R / L channel components, and generating reverberation data corresponding to each R / L channel component. 10a is a multiplier 8
The adder 10b for adding the R channel waveform data output from the a and the R channel reverberation data output from the reverberation generating unit 9 includes the L channel waveform data output from the multiplier 8b and the reverberation. It is an adder that adds L channel reverberation data output from the generation unit 9.

Next, reference numeral 11 denotes a crosstalk canceller which is an inverse characteristic circuit of crosstalk generated corresponding to the positional relationship between the speaker in the reproduction space and the listener, and is an adder 10a.
The process of canceling the crosstalk is performed in advance on the waveform data of the R / L channel components output from the and 10b. Reference numeral 12 is a D / A converter that converts the waveform data (digital data) output from the crosstalk canceller 11 into an acoustic signal (analog signal), and 13 is the D / A converter 1.
2 is an amplifier that amplifies the acoustic signal converted in 2 and supplies it to the left and right speakers (not shown).

With such a structure, by the operation described below, it is possible to localize the tone color sound at the target sound image position specified by the vertical angle θ ₁ , the horizontal angle ψ ₁ , and the distance D ₁ . For example, when the tone color data ST is given to the waveform memory 1 ′ by an operation such as pressing a keyboard (not shown),
Waveform data of seven series of tone colors corresponding to the tone color data ST is output as time-division serial data. After that, in the demultiplexer 3, the time-division serial data output from the waveform memory 1'is converted into 7 series of parallel data, and each waveform data is multiplied by a multiplier 4a corresponding to the corresponding points A to G. ~ 4g.

The vertical angle θ ₁ and the horizontal angle ψ ₁ of the target sound image position are determined by rotating the vertical angle dial 2a ₁ and the horizontal angle dial 2a ₂ of the indicator 2a. Further, the distance D ₁ is determined by sliding the distance slider 2a ₃ . The vertical angle θ ₁ , the horizontal angle ψ _1, and the distance D ₁ are transmitted to the control unit 2b, and the control unit 2b
from b, and the multiplier 4a-4g, the multiplication coefficient G _A ~G _G corresponding to the vertical angle theta ₁ is a multiplier 6a and the multiplier 6b is
The multiplication coefficients a and b according to the distance D ₁ are provided to the multipliers 8a and 8b, and the multiplication coefficients c and d according to the horizontal angle ψ _1.
Are supplied respectively.

Here, the relationship between the multiplication coefficients G _{A to} G _G and the vertical angle θ ₁ is as shown in FIG. In FIG. 3, for example, when the vertical angle θ ₁ = 30 °, in the multiplication coefficients G _{A to} G _G , only GB becomes 1 and the other multiplication coefficients become 0. Next, when the vertical angle θ ₁ changes by more than 30 ° by operating the vertical angle dial 2a ₁ of the indicator 2a, the multiplication coefficient G _B becomes small and the multiplication coefficient G _C becomes large. At this time, other multiplication coefficients remain 0. The sum of the multiplication coefficients G _B and G _C is set to 1, and the vertical angle θ
_{When 1} = 45 °, G _B = G _C = 0.5, and the waveform data at a position where no waveform data is collected can be synthesized by interpolating the collected waveform data.

Next, the waveform data multiplied by the multiplication coefficients G _{A to} G _G in the multipliers 4a to 4g are added in the adder 5 and then supplied to the multipliers 6a and 6b. As shown in FIG. 4, the multipliers 6a and 6b have a multiplication coefficient which becomes smaller as the distance D ₁ becomes larger, and
On the contrary, a large multiplication coefficient b is supplied from the localization control device 2. Therefore, in the multiplier 6a, the waveform data multiplied by the multiplication coefficient a is input to the delay unit 7, and R
Channel 8 and L channel component are separated, and multiplier 8a
And 8b.

The multipliers 8a and 8b have a large multiplication coefficient c when the horizontal angle ψ ₁ is close to 90 °.
And, on the contrary, the multiplication coefficient d which becomes small is supplied from the localization control device 2. Therefore, the multipliers 8a and 8b
The waveform data multiplied by the multiplication coefficients c and d in is input to the adders 10a and 10b. In the multiplier 6b, the waveform data multiplied by the multiplication coefficient b is input to the reverberation generating unit 9, separated into R channel and L channel components, and processed into reverberation data. next,
The reverberation data of the R channel and L channel components are added to multipliers 8a and 8b in adders 10a and 10b.
The waveform data is supplied to the crosstalk canceller 11 and added.

Next, in the crosstalk canceller 11, the crosstalk of the acoustic signals of the R / L channel components output from the adders 10a and 10b is canceled in advance. After that, in the D / A converter 12, it is converted into an analog acoustic signal and supplied to the amplifier 13. In the amplifier 13, the acoustic signal undergoes a predetermined amplification and is output to the left and right speakers (not shown). As described above, the localization of the distance D1 is the ratio of volume and reverberation data, the localization of the horizontal angle ψ ₁ is the amplitude difference and delay time difference of the left and right channel components, and the localization of the vertical angle θ ₁ is the waveform from the waveform memory 1 ′. Data reading and weighting are performed respectively.

In the above-described embodiment, all the 7 series of waveform data are read at the same time, but only two types of waveforms required for interpolation may be read. In that case, when other waveform data is required due to the movement of the designated sound image position, it is preferable to perform the interpolation by configuring the waveform data to be read from an address in the middle of the waveform data. Further, well-known loop processing may be applied to the waveform data stored in the waveform memory 1 '. In particular, it is effective when the capacity of the waveform memory 1'is small and a sufficiently long sampling time cannot be secured.

Further, although the waveform data corresponding to only the front vertical direction is used, the waveform data corresponding to the positions finely distributed over the whole sky may be used. Moreover, when making it correspond to the vertical direction, it is not always necessary to make it correspond to the front vertical direction. When the waveform is stored in correspondence with the vertical direction deviated from the front, the delay difference and the amplitude difference given by the horizontal angle may be corrected.
Further, since the example in which the speaker is used as the device for converting the acoustic signal into the sound is shown, the crosstalk canceller 11
However, the crosstalk canceller 11 is not necessary if the headphones are used for listening.

[0030]

As described above in detail, the first aspect of the present invention is as follows.
According to the invention described in (3), waveform data is stored for each of a plurality of predetermined positions in the space, and the waveform data is selectively generated in correspondence with a designated spatial position. Therefore, a clear localization sound image can be obtained with a small-scale configuration.

According to the second aspect of the invention, the waveform data is stored in correspondence with a plurality of predetermined discrete positions in the space, and the waveform data is stored in correspondence with the designated spatial position. Since a plurality of values are read and weighted and added, waveform data corresponding to positions between discrete positions can be obtained. By doing so, the sound image position can be smoothly moved by smoothly changing the weighted value given to the plurality of waveform data.

According to the third aspect of the present invention, the waveform data is stored in correspondence with a plurality of predetermined vertical direction directions of the space, and the vertical direction direction component of the designated spatial position is stored. Since the waveform data is selectively generated and the delay time difference and the amplitude difference between the left and right channels are given in accordance with the horizontal angular direction component of the designated spatial position, the vertical and horizontal angular directions of the space are specified. The amount of data to be stored can be smaller than that in the case of storing the waveform data corresponding to the sound source at any position in the space to be stored.

Since the positions in the vertical direction are symmetrical with respect to both ears, a considerable degree of rigor is required to obtain a clear sense of localization, so the waveforms are directly corresponded. On the other hand, in the horizontal angle direction, the waveform is omitted because a sufficient localization feeling can be obtained simply by providing the signal characteristic differences such as the delay difference and the amplitude difference to both ears. That is, it is possible to reduce the amount of data to be stored while maintaining a sufficient sense of localization in both the vertical and horizontal directions.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a schematic configuration of a localization control device 2.

FIG. 3 is a diagram showing a relationship between a vertical angle θ and multiplication coefficients G _{A to} G _G.

FIG. 4 is a diagram showing a relationship between a distance D and multiplication coefficients a and b.

5 is a diagram for explaining a method of collecting waveform data in the waveform memory 1. FIG.

[Explanation of symbols]

1 '... Waveform memory, 2 ... Localization control device, 4a-4g
... multiplier, 5 ... adder, 6a, 6b ... multiplier, 7
... delay section, 8a, 8b ... multiplier, 9 ... reverberation generation section.

Claims (3)

[Claims] 1. A storage unit for storing a plurality of waveform data corresponding to a plurality of predetermined positions in a space, a position designating unit for designating a position in the space, and a unit for reading the waveform data from the storage unit. ,
A localization sound image generating apparatus comprising: a waveform data generating unit that selectively generates waveform data corresponding to the position designated by the position designating unit. 2. A storage means for storing a plurality of waveform data corresponding to a plurality of predetermined discrete positions in a space, a position specifying means for specifying a position in the space, and a means for reading the waveform data from the storage means. There
A localization sound image generating apparatus comprising: a weighting addition means for performing weighted addition on a plurality of waveform data read out according to the position designated by the position designating means. 3. A storage means for storing a plurality of waveform data corresponding to a plurality of vertical positions in a space, a position designating means for designating a position in the space, and a waveform data read from the storage means. There
Waveform data generating means for selectively generating waveform data according to the vertical component of the position designated by the position designating means, and according to the horizontal angular component of the position designated by the position designating means A localization sound image generation apparatus comprising: a conversion unit that applies a delay time difference and an amplitude difference to the right channel component and the left channel component of the waveform data generated by the waveform data generation unit.