JPH0546193A - Reflected sound extraction device - Google Patents

Abstract

(57) [Abstract] [Purpose] Reflection sound obtained by measurement or calculation is projected on a plane formed by a reproduction speaker and a listener, and the projected reflection sound is synthesized as a virtual sound image. The reflected sound is extracted by dividing the sound. [Structure] A plurality of reflected sounds externally obtained by measurement or simulation such as a sound ray method is input from a first input terminal 6 and stored in a storage unit 1. In the projection means 2, the reflected sound stored in the storage means 1 is projected on the plane formed by the speakers 9, 10, 11, 12 and the listener 13. Next, the calculation means 3 divides the reflected sound projected as described above so as to be synthesized as a virtual sound image. The four sets of reflected sounds obtained by dividing in this way are set in the sound field control device 5 by the setting means 4. The sound field control device 5 convolves the obtained four sets of reflected sound sequences with the music signal input to the second input means 7, and radiates them from the corresponding speaker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflected sound extraction device which is set in a sound field variable control device which creates an arbitrary sound field in a normal room.

[0002]

2. Description of the Related Art In recent years, with the development of hall simulation technology and the digitization of audio equipment, the need for sound field control has rapidly increased. This sound field control is used by a device that creates an arbitrary sound field by convoluting (multiplying and adding) a music signal and a certain reflected sound sequence (or simply called reflected sound), which is called a sound field variable device. To be done. The convolution operation in the sound field varying device is realized by a DSP (digital signal processor) or a discrete IC, but the number of reflected sounds to be convolved is limited due to the current performance of the DSP or IC, and it is usually practical. The reflected sound measured in a well-known hall or the reflected sound obtained by calculation such as simulation is thinned out (compressed) before use.

A method for controlling a sound field by adding a reflected sound will be described below with reference to the drawings.

FIG. 14 is a diagram schematically showing a reflected sound when a musical instrument is played in an actual hall or the like. As shown in this figure, the sound radiated from the piano 110, which is the sound source, is reflected on the ceiling, side walls, etc., and reaches the listener. In the figure, the number of reflected sounds is limited because it is shown schematically, but in reality there are innumerable reflected sounds. Further, the respective reflected sounds do not arrive at the same time, but arrive with a time delay according to their respective propagation distances.
A listening room 111, which is a normal room, is also shown in the center of (FIG. 14). If the reflected sound of the hall shown in the figure is reproduced in this listening room 111, In the listening room, you can hear the sound of the piano playing in the hall.
(FIG. 15) is a more simplified representation of (FIG. 14),
A large rectangular parallelepiped 112 represents a hall and a small rectangular parallelepiped 113 represents a listening room. This big cuboid 11
When the reflected sound that reaches the listener S near the center when a certain sound source is sounded in the hall represented by 2 is X, Y, Z, the reflected sound X, Y, Z is reproduced in the listening room. To do this, the reflected sound X, in the hall from the speaker arranged at the position of x, y, z as shown in FIG.
It is only necessary to reproduce a signal having the same magnitude and time delay as Y and Z (however, in this case, there are three reflected sounds, but in reality there are countless speakers, so there are countless speakers. is necessary.).

As described above, as a method of controlling the sound field by reproducing the reflected sound of the hall in the listening room, innumerable speakers are arranged on the wall of the listening room, and the time delay from each speaker is taken into consideration. A method of sounding each reflected sound can be considered.

[0006]

However, the above-described structure has a problem that an innumerable speaker and an innumerable time delay device are required.

The present invention has been made in view of the above problems, and a reflected sound obtained by measurement or calculation is used to generate a virtual sound image from a limited number of speakers and a limited reflected sound. The present invention provides a reflected sound extraction device that sets a sound field control device that controls a sound field with an inexpensive configuration.

[0008]

In order to solve the above problems, the reflected sound extraction apparatus of the present invention is a storage means for inputting and storing the reflected sound obtained by measurement or the like from the outside, and storing it in the storage means. Projecting means for projecting the reflected sound that is actually emitted on a plane created by a speaker and a listener, and computing means for dividing each reflected sound obtained by the projecting means into a reflected sound that is synthesized as a virtual sound image, There is provided a setting means for setting the reflected sound obtained by the calculating means in the sound field control device for creating an arbitrary sound field by convolving the reflected sound and the input music signal.

[0009]

With the above arrangement, the present invention makes it possible to create an infinite number of reflected sounds by a limited number of speakers by the method of creating a virtual sound image.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reflected sound compression apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a reflected sound extracting apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 6 denotes a first input terminal for inputting a plurality of reflected sounds obtained by measurement or calculation to the storage means 1, 1
Is a storage means for inputting and storing a plurality of reflected sounds obtained by measurement or calculation externally from the first input terminal 6, and 2 is a sound field control device 5 for each reflected sound stored in the storage means 1. By means of a speaker that actually emits sound and a projection means for projecting on a plane formed by the listener, 3 is a computing means for dividing the reflected sound obtained by the projection means 2 so that it can be synthesized as a virtual sound image by two speakers, Setting means for setting the reflected sound divided by the calculating means 3 in the sound field control device 5, 7 is a second input terminal for inputting a music signal to the sound field control device 5, and 5 is a reflection set by the setting means 4. Sound and second
, A sound field control device for creating an arbitrary sound field by convolving the music signal input from the input terminal 7, 8 is a listening room for actually listening to the signal processed by the sound field control device 5, 9, 10, Reference numerals 11 and 12 denote speakers, which are arranged at the four corners of the listening room 8, and which actually emit the processed signal output from the sound field control device 5 as sound, and 13 denotes a listener. In the following, description will be given by attaching the same reference numerals to those having similar functions.

The operation of the reflected sound extraction device configured as described above will be described below (FIG. 1).

First, a plurality of reflected sounds obtained externally by measurement or simulation such as the sound ray method are input from the first input terminal 6 and stored in the storage means 1.
The specific value to be stored is the volume, direction, time delay (to the direct sound) of the reflected sound, etc. Since the capacity of the storage means 1 is limited, only that capacity is stored (actually,
The amount is determined by the number of reflected sounds that can be processed by the sound field control device 5. ).

FIG. 2 shows the state of the reflected sound geometrically obtained by the ray method. In FIG. 2, the solid line indicates the shape of the hole, which is seen from diagonally above, and the sound emitted from the sound source O reaches the listener S ′ and is reflected by the dotted line. There is. Although eight reflected sounds are shown in this figure, there are innumerable reflected sounds in reality.

Next, in the projection means 2, the reflected sound stored in the storage means 1 is converted into the speakers 9, 10, 11, 1.
2 and the listener 13 to project on a plane. Speaker 9,
Planes A, B, C made by 10, 11, 12 and the listener 13
D is shown in (FIG. 3). The plane projected as in this figure is
Basically, it is a triangular plane created by two speakers and the listener.

A projection method performed by the projection means 2 will be described with reference to FIG. Reference numeral 14 denotes a reflected sound coming from the front of the listener 13 and slightly above, and 15 denotes a reflected sound coming from the listener 13 slightly behind and to the right. However, the magnitude of the reflected sound is represented by the length of the arrow. Reflected sound 14 is plane A
Is projected on the plane A assuming that the direction and the time of the component parallel to are parallel to the plane A, and the reflected sound 15 is also projected onto the plane C assuming that the direction of the component parallel to the plane C is equal to the time and the magnitude. Sounds 16 and 17 are produced. Hereinafter, the same projection is performed on all the reflected sounds stored in the storage unit 1.

Next, the calculation means 3 divides the reflected sound projected as described above so as to be synthesized as a virtual sound image. That is, as shown in (FIG. 4), the reflected sound 16 projected is in each direction connecting the speaker 9 and the listener 13 and the speaker 10 and the listener 13 so that the reflected sound 16 is synthesized by the speakers 9 and 10. The vector component (a, b) of the reflected sound 16 is obtained. Similarly, for the projected reflected sound 17, the speaker 11, the listener 13, and the speaker 1 so that the reflected sound 17 is synthesized by the speakers 11 and 12.
The vector component (c, d) of the reflected sound 17 in each direction connecting 2 and the listener 13 is obtained. Therefore, four rows of reflected sound to be emitted from each speaker can be provided for each speaker.

The above calculation is performed for each reflected sound obtained by the projection means 2. The sound field control device 5 sets the four reflected sounds obtained by dividing in this way by the setting means 4.
Set to.

The sound field control device 5 convolves the obtained four sets of reflected sound sequences with the music signal inputted to the second input means 7, and radiates the consonant sound from the corresponding speaker. As a result, the listener 13 will hear the sound added with the reflected sound obtained by the projection means 2 as a virtual sound image.

In the first embodiment, there are four speakers arranged in the room and they are arranged at the four corners of the room.
Eight speakers 19, 20, 21, 2 as shown in FIG.
Similarly, when 2, 23, 24, and 25 are respectively arranged at the vertices of a rectangular parallelepiped, the plane projected by the projection unit 2 is E to
L is set so that the reflected sound of the plane and the portion surrounded by the plane is not projected onto one plane, but the reflected sound is synthesized as a virtual sound image on each plane similarly to the arithmetic means 3. Divide into and project. In other words, (Fig. 6
As shown in (a)) of the listening room shown in (FIG. 5) as seen from the left side ((FIG. 6 (b)) as seen obliquely from above left), the plane E If there is a reflected sound 26 between the plane I and the plane I, it is divided into reflected sounds e and f. The reflected sound is extracted by performing the same process thereafter. As described above, the projected plane and the projection method are different depending on the relationship between the speaker and the listener to be arranged (for example, all the triangular planes formed by the speaker and the listener as shown in FIG. 7). However, it is preferable that the virtual sound image is not complicated by using as few speakers as possible. This is the same in the second to fourth embodiments described below.) ..

FIG. 8 is a block diagram of a reflected sound extracting apparatus according to the second embodiment of the present invention. In FIG. 8, reference numeral 101 denotes a reflected sound selection unit that selects a limited number of reflected sounds stored in the storage unit 1 in descending order of magnitude.

First, a plurality of reflected sounds externally measured or simulated by a sound ray method or the like are input from the first input terminal 6 and stored in the storage means 1.
The amount of reflected sound stored here is determined by the capacity of the storage unit 1.

Next, the reflected sound selecting means 101 selects the reflected sounds from the reflected sounds stored in the storage means 1 in descending order of size. Thereby, the sound field control device 5
It is possible to optimally select the reflected sounds corresponding to the number of reflected sounds that can be processed in.

(FIG. 9 (a)) is the reflected sounds stored in the storage means 1, (FIG. 9 (b)) is one in which these reflected sounds are numbered in descending order, (FIG. 9 (c)). 3 is a schematic diagram of the reflected sound selected by the reflected sound selection means 101,
The vertical axis shows the amplitude and the horizontal axis shows the discrete time (however,
Actually, the directions in which the reflected sounds arrive are different, but in this figure, the totally reflected sounds are shown coaxially. ). By doing so, for example, when the half of the reflected sounds that can be processed by the sound field control device 5 is five and the reflected sound selection means 101 is not provided, the initial reflected sounds (the first five reflected sounds) Only the reflected sound) will be processed even if its size is small, and the large reflected sound at the rear will be ignored. By providing the reflected sound selection unit 101, the larger the amplitude of the reflected sound, the better the characteristics of the room are represented, and thus it is possible to avoid this.

From the reflected sound thus selected, the reflected sound is extracted by projecting and dividing in the same manner as in the first embodiment, and set in the sound field control device 5.

FIG. 10 is a block diagram of a reflected sound extracting apparatus according to the third embodiment of the present invention. In FIG. 10, reference numeral 102 divides the reflected sound obtained by the computing means 3 into certain time intervals, extracts only the largest reflected sound within that time period, and other reflected sounds are zero. And thinning means.

Similar to the second embodiment, the reflected sound obtained up to the calculation means 3 is input to the thinning means 102. FIG. 11 is an explanatory diagram of thinning performed by the thinning means 102. (FIG. 11A) is a train of reflected sounds to be radiated from the speaker 9 obtained by the calculating means 3,
(FIG. 11 (b)) is a sequence of the reflected sound shown in (FIG. 11 (a)) divided into a certain time interval T (preferably about 50 msec), and (FIG. 11 (c)) is at this time T. The largest reflected sound is extracted and the other reflected sounds are set to zero. Similar to (FIG. 9), the vertical axis represents amplitude and the horizontal axis represents discrete time. In this way, the reflected sound to be emitted from each speaker is thinned out. When this process is performed, a virtual sound image may not be created, but this can be prevented by adopting an algorithm that leaves the reflected sound that should be a pair of the extracted reflected sounds.

The reflected sound culled in this way is set in the sound field control device 5 by the setting means 4. This makes it possible to more optimally extract the number of reflected sounds that can be processed by the sound field control device 5.

FIG. 12 is a block diagram of a reflected sound extracting apparatus according to the fourth embodiment of the present invention. In FIG. 12, reference numeral 103 divides the reflected sound obtained by the calculating means 3 into a certain time interval, integrates the magnitude of the reflected sound within that time, and further sets the value to the maximum within that time. It is an integration means that stands at a position of a large reflected sound and thins out other reflected sounds as zero.

Similar to the second embodiment, the reflected sound obtained up to the calculation means 3 is input to the integration means 103. (Fig. 1
3) is an explanatory diagram of thinning-out performed in the integrating means 103. (FIG. 13A) is a train of reflected sounds to be radiated from the speaker 9 obtained by the calculation means 3, and (FIG. 13B) is the reflected sound shown in (FIG. 13A) for a certain time. Divided into intervals T (about 50 msec is good),
(Fig. 13 (c)) Integrates the magnitude of the reflected sound within this time T, sets the value at the position of the largest reflected sound within that time, and sets the other reflected sounds to zero. Similar to (FIG. 9), the vertical axis represents amplitude and the horizontal axis represents discrete time. In this way, the reflected sound to be emitted from each speaker is thinned out. When this processing is performed, the effect of the actually reproduced sound field becomes large, although it deviates from the purpose of creating a virtual sound image.

The reflected sound culled in this way is set in the sound field control device 5 by the setting means 4. This makes it possible to more optimally extract the number of reflected sounds that can be processed by the sound field control device 5.

[0032]

As described above, according to the present invention, the reflected sound obtained by measurement or the like is projected onto the plane composed of the speaker to be reproduced and the listener by the projection means, and the reflected sound thus obtained is imaginary. Even when the number of speakers is small and the number of processable reflected sounds is limited by dividing the sound so that it can be synthesized as a sound image, the reflected sound set in the sound field control device that can create an arbitrary sound field can be set. It can be extracted.

[Brief description of drawings]

FIG. 1 is a block diagram of a reflected sound extraction device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a reflected sound geometrically obtained by a sound ray method.

FIG. 3 is a diagram illustrating a projection plane of a projection unit according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a projection method of a projection unit according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating another speaker arrangement and a projection plane in the first embodiment of the present invention.

FIG. 6 is a diagram illustrating another projection method according to the first embodiment of the present invention.

FIG. 7 is a diagram showing another speaker arrangement and a projection plane in the first embodiment of the present invention.

FIG. 8 is a block diagram of a reflected sound extraction device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a reflected sound selecting method in reflected sound selecting means in the second embodiment of the present invention.

FIG. 10 is a block diagram of a reflected sound extraction device according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a method of thinning a reflected sound by a thinning means in a third embodiment of the present invention.

FIG. 12 is a block diagram of a reflected sound extracting device according to a fourth embodiment of the present invention.

FIG. 13 is a diagram showing a thinning method of reflected sound in the integrating means in the fourth embodiment of the present invention.

FIG. 14 is a schematic diagram of a reflected sound of a hall or the like for explaining a conventional sound field control method.

FIG. 15 is a simplified diagram of a reflected sound from a hall or the like for explaining a conventional sound field control method.

[Explanation of symbols]

 1 Storage Means 2 Projection Means 3 Computing Means 4 Setting Means 5 Sound Field Control Device 6 First Input Terminal 7 Second Input Terminal 8 Listening Room 9, 10, 11, 12 Speakers 13 Listener 101 Reflected Sound Selection Means 102 Decimation Means 103 Integrating means

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroko Numazu 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A storage unit for inputting and storing a reflected sound of a room obtained by measurement or calculation from the outside, a speaker and a listener for actually emitting the reflected sound stored in the storage unit. A projection means for projecting on a plane formed by the above, a calculation means for dividing the reflected sound obtained by the projection means into a reflected sound that is synthesized as a virtual sound image, and a reflected sound obtained by the calculating means. And a setting means for setting the sound field control device for creating an arbitrary sound field by convolving the input music signal with the reflected sound extraction device. 2. A storage means for inputting and storing the reflected sound of the room obtained by measurement or calculation from the outside, and a large amplitude of the reflected sound stored in the storage means, in order from the largest.
A reflected sound selecting means for selecting only a limited number of reflected sounds;
Projecting means for projecting the reflected sound selected by the reflected sound selecting means onto a plane that is actually radiated by a speaker and a listener, and each reflected sound obtained by the projecting means are combined as a virtual sound image. A calculation means for dividing the reflected sound into a reflected sound and a setting means for setting the reflected sound obtained by the calculating means in a sound field control device for creating an arbitrary sound field by convolving the reflected sound and an input music signal. And a reflected sound extraction device. 3. A storage means for inputting and storing the reflected sound of the room obtained by measurement or calculation from the outside, and a large amplitude of the reflected sound stored in the storing means, in order from the largest.
A reflected sound selecting means for selecting only a limited number of reflected sounds;
Projecting means for projecting the reflected sound selected by the reflected sound selecting means onto a plane that is actually radiated by a speaker and a listener, and each reflected sound obtained by the projecting means are combined as a virtual sound image. A first calculation means for dividing the reflected sound into a reflected sound; a second calculation means for thinning out the reflected sound obtained by the first calculating means under a predetermined condition; and a reflected sound obtained by the second calculating means. A reflected sound extraction device comprising: a sound field control device that creates an arbitrary sound field by convolving the reflected sound and an input music signal. 4. The second calculating means divides the reflected sound obtained by the first calculating means at a certain time interval and leaves only the reflected sound having the largest amplitude within that time, and within that time. The reflected sound extraction device according to claim 3, wherein the reflected sound of is zero. 5. The second calculating means divides the reflected sound obtained by the first calculating means at a certain time interval, integrates the reflected sound within that time, and obtains the value as the best value within that time. The reflected sound extraction device according to claim 3, wherein the reflected sound is set to a time when the amplitude is large, and the other reflected sounds within that time are zero.