JP2932801B2 - 3D sound field simulation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional sound field simulation method for simulating a sound field in a design stage.
The acoustic characteristics of the sound field at the design stage that have not yet been constructed are obtained as impulse responses for each direction at the position of the listener by numerical calculation using a solid angle, and
Input the sound obtained in the sound field accurately to the left and right ears of the listener
To this end, the impulse response is subjected to processing to determine the response to be input to both ears of the listener based on the acoustic characteristics of the listener, and the response to each of the right and left ears is performed.
Information directly from the numerical simulation
That is, at the stage of the numerical simulation,
To calculate the response of
The present invention relates to a three-dimensional sound field simulation method for creating a sound field in two systems of a left channel and a right channel based on the three channels.

[0002]

2. Description of the Related Art As is well known, in a music hall or the like, it is important to analyze a sound field at the design stage. For this reason, as a technique for analyzing the sound field, a virtual image method of a geometric method or the like is known. . The virtual image method is based on Fermat's theorem that a phenomenon in the natural world proceeds through the shortest distance, and obtains a sound response by geometrically tracking a sound reaching a sound receiving point. As a technique for reproducing the sound field from the calculated response, a plurality of speakers are appropriately arranged in a space such as an anechoic room where unnecessary reflected sound does not occur, and a listening (listening) is performed in the center of the room.
That is being done.

[0003]

However, in the geometric simulation represented by the virtual image method, there is a problem that sound diffraction is not possible because the sound is handled geometrically. That is, in the geometric simulation,
Acoustic simulation can be performed properly only under limited conditions where sound diffraction can be ignored.However, simulation accuracy is not good because it is special and sound diffraction is often not negligible. Was difficult to do. At the actual sound receiving point, not only the direct sound from the sound source but also the reflected sound comes from any direction, but the speaker for simulating this is infinite in an anechoic room or other space. However, the simulation accuracy is limited due to the limitation of the number of speakers. In addition, arranging a large number of speakers in an anechoic room or the like is not desirable in terms of equipment cost because the installation place of the apparatus is limited.

As a technique for reproducing a three-dimensional sound field using two systems of a left channel and a right channel, a HATS (Head And Torso Simul) as shown in FIG.
ator), that is, a doll simulating the head and torso of a human being with microphones placed on the left and right ears, and when reproducing this, the cross between the left and right channels is used. It is known to perform a frontal correction for canceling the talk, correcting the speaker characteristics, and fitting the characteristics of the HATS shape and the like to those of the listener, but this is a recording / reproducing technique in an existing sound field, and is generally used. It has not been established as a simulation technique.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of calculating the acoustic characteristics of a sound field in a design stage, which does not actually exist, by a numerical calculation process using a solid angle. Make it possible to obtain the impulse response according to the direction at the position, and accurately obtain the sound obtained in the virtual sound field.
In order to input to both the left and right ears, the impulse response is subjected to processing to determine the response to be input to the both ears of the listener based on the acoustic characteristics of the listener.
Numerical simulation of information up to the response in human ears?
By calculating directly from
Even calculating the responses for the left and right ears at the
By doing so, it is possible to create a three-dimensional sound field with two systems of the left channel and the right channel based on the result of this numerical operation , perform sound field simulation with high accuracy, and have a large degree of freedom in the simulation form. An object of the present invention is to provide a three-dimensional sound field simulation method that is advantageous in terms of cost.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method for designing a hole or the like in a design stage which has not been constructed yet .
A three-dimensional sound field simulation method for simulating a sound field that does not actually exist , wherein a three-dimensional sound field in a sound arrival direction of one sound receiving point in the sound field is obtained. Calculate the impulse responses corresponding to the angles, perform processing for giving the acoustic characteristics of the left and right ears to each of the calculated impulse responses, and then perform processing for distributing and combining the impulse responses into the left channel and the right channel. By
All the calculation results of the calculated sound field are
After consolidating into only two channels, a sound field is simulated by two systems of a left channel and a right channel.

[0007]

Stated operation of the present invention, first, in the design stage, such as holes to be constructed for example new, real
Is numerically analyzed for the acoustic characteristics of the hole that do not exist in , and this is obtained as an impulse response. Specifically, for one sound receiving point in the target sound field ,
Numerical analysis is performed by calculating an impulse response corresponding to a solid angle in the direction of arrival of the sound reaching the sound receiving point . The impulse response indicating the acoustic characteristics of the sound field at the design stage obtained by the numerical analysis in this way is a prediction of the acoustic characteristics of the arrival direction of a specific sound at a specific sound receiving point of the sound field. This is the basic data for creating a simulation. After that, by using the process of giving the acoustic characteristics of the left and right ears to the calculated impulse responses, each impulse response can be converted into the one corresponding to the left and right ears of the listener. Next, by distributing and synthesizing these impulse responses to the left channel and the right channel, all the calculated results of the sound field are converted to the left channel.
It is possible to combine only two channels, that is, a right channel and a right channel, and generate impulse responses of two left and right channels to be input to the right and left ears of the listener at the sound receiving point. Cost
To the left and right ears at the stage of numerical simulation
Information from the numerical simulation to the response
The calculation is performed directly, and based on the result of the numerical operation,
And create a sound field with two systems, the left channel and the right channel
Like that. Then, based on these impulse responses, it is possible to simulate an extremely realistic three-dimensional sound field in two systems of the left channel and the right channel.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention. The present invention is a three-dimensional sound field simulation method for simulating a sound field in a design stage. In this embodiment, first, for one sound receiving point in a sound field , the arrival of a sound reaching the sound receiving point is considered. The impulse response corresponding to the solid angle in the direction is calculated, and the acoustic characteristics of a sound field that does not actually exist yet are predicted by this numerical analysis. The impulse response calculated by this calculation is Kirchho, which is an integral expression of the wave equation.
The integral equation of ff is used as a basic equation, and the elements to be discretized are set as the in-phase elements of the wavefront, and the calculation can be performed in the real time domain while the number of elements is relatively suppressed. The solid angle of the sound receiving point in the sound field extends in all directions around the sound receiving point, and indicates the direction of arrival of the sound with respect to the sound receiving point. More specifically, the sound receiving point is obtained by appropriately dividing the solid angle into variables to obtain an impulse response. Therefore, an impulse response is obtained for each direction, which is a prediction of the acoustic characteristics of the space relating to the sound receiving point, that is, the sound field.

Next, processing for giving acoustic characteristics of the left and right ears to each of the calculated impulse responses is applied. Humans perceive sound coming from a certain direction by the left and right ears, and determine the direction of arrival by the acoustic characteristics of the left and right ears, that is, the level difference between the left and right ears,
Since the time difference, the difference in frequency characteristics, the phase difference, and the like are specified empirically, the correction of the acoustic characteristics of the left and right ears is given to each impulse response, which can be said to be for each direction, according to the direction. By this processing, each impulse response can be converted into one corresponding to the left and right ears of the listener. Sand
In addition, the sound obtained in the virtual sound field is accurately
Input, the response to each ear
Information is calculated directly from numerical simulation
doing.

[0010] Thereafter, the impulse responses of the left and right ears are distributed and synthesized into a left channel and a right channel. By this combination, acoustic characteristics corresponding to the left and right ears of the listener at the sound receiving point can be obtained. To perform this synthesis processing
To calculate all the calculated results of the sound field on the left channel and the right channel.
We are trying to aggregate only two channels,
The left and right ears
Execute until calculating the answer. Then, based on the impulse responses distributed to the left and right, a sound field is created in two systems of the left channel and the right channel, so that a sound field in a design stage that does not actually exist can be simulated. Here, two left and right two speakers are used. FIG.
As shown in (1), it is necessary to cancel the left-right channel crosstalk (CLCR), that is, the sound coming from the right speaker 1 to the left ear is canceled by the sound emitted from the left speaker 2, and vice versa. To process. Further, for the front correction (EL, ER), the reproduction system including the speaker (TL, TR) is also corrected for each channel. This reproduction technique itself is already known in Japanese Patent Application Laid-Open No. 2-86399. The right speaker 1 and the left speaker 2
Is appropriate, such as a fixed type that is grounded on the floor or the like, or a headphone type that is set on the head by the listener.

As described above, the acoustic characteristics of the sound field at the design stage are numerically analyzed, and more specifically, the impulse corresponding to a specific direction at a sound receiving point of the sound field is calculated by a numerical operation using a solid angle. Calculate the response and get it in a virtual sound field
In order to accurately input sound to the listener's left and right ears, each impulse response is corrected for acoustic characteristics corresponding to the listener's left and right ears, and these impulse responses are distributed to the left channel and the right channel Combine them, left and right
Numerical simulation of information up to the response at each ear
Is calculated directly from the
Even calculating the responses for the left and right ears at the
The impulse response of the left and right two channels to be input to the right and left ears of the listener at the sound receiving point can be generated based on the result of the numerical operation. Based on these impulse responses, two systems of the left channel and the right channel can be generated. Thus, a very realistic three-dimensional sound field can be simulated. In particular, since this impulse response is obtained for each direction in terms of the solid angle, the localization created in spite of the left and right channels is exactly three-dimensional, and an extremely realistic three-dimensional sound field full of a sense of reality can be created. Therefore, the sound field simulation can be performed with high accuracy by increasing the dispersion number of solid angles, that is, the number of operations of impulse response, and the simulation accuracy is theoretically unlimited. In addition, since the system is based on the two systems of the left channel and the right channel, there is an advantage in terms of equipment costs.

[0012]

As described above in detail, according to the three-dimensional sound field simulation method of the present invention, one sound receiving point in the sound field at the design stage reaches the sound receiving point.
It reaches the direction of arrival of the impulse response corresponding to a solid angle of sound calculated, for each impulse response calculated for the impulse response corresponding to the left and right ears AUDIO's processing performed giving the acoustic characteristics of the left and right ears After the conversion, the sound field calculated by performing a process of distributing and synthesizing those impulse responses into the left channel and the right channel
All the calculation results of the two channels of the left channel and the right channel
By consolidating to learn, have so as to create a sound field in the two systems of left and right channels to obtain the impulse response of the two channels corresponding to the audition's left and right ears, such
The information up to the response of each ear to the left and right
By calculating directly from the
Calculate the response of the left and right ears during the numerical simulation
This numerical operation result
The sound obtained in the virtual sound field based on the
The sound can be input to both ears, and a three-dimensional sound field can be created by the two systems of the left channel and the right channel. To provide a three-dimensional sound field simulation method which is advantageous to
An extremely realistic three-dimensional sound field can be simulated. Then, the impulse response is obtained for each direction with respect to the solid angle at a certain sound receiving point. Therefore, although the left and right channels are used, the localization created is exactly three-dimensional, and a three-dimensional sound field can be obtained. Moreover, the sound field simulation can be performed with high accuracy as the number of divisions of the solid angle of the impulse response is increased, and since the simulation is simply performed by two systems, the degree of freedom of the simulation form is large and the facility cost is advantageous. is there.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a reproducing system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a conventional HATS technology related to the present invention.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsutoshi Watanabe 4-640 Shimoseito, Kiyose-shi, Tokyo Inside Obayashi Corporation Technical Research Institute (56) References JP-A-1-135222 (JP, A) JP-A-3 -254298 (JP, A) JP-A-2-224600 (JP, A) JP-A-2-86399 (JP, A) Sound technology 1984 vol. 13, no1 (no45) PP13-19 (58) Fields investigated (Int. Cl. ⁶ , DB name) H04S 1/00 H04S 7/00 G10K 15/00

Claims (1)

(57) [Claims] (1)Not yet constructedAt the design stagehole
Does not exist in realityA three-dimensional sound that simulates the sound field
A field simulation method, comprising:OneAbout the receiving point, To the receiving point
To reachImpulse response corresponding to solid angle of sound arrival direction
And calculate the left and right for each impulse response
Perform the process of giving the acoustic properties at the ear, and then
The impulse response to the left and right channels
ProcessPerforms all calculations of the sound field
Results are aggregated to only the left and right channels.
Later, the sound field is simulated by the two systems of the left channel and the right channel.
Three-dimensional sound field simulation method characterized by creation
Law.