JP2006014070A - Sound system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound system for supplying sound only to viewers existing within the range of a target position in a point-like restriction without such a burden for the viewers to attach a device. <P>SOLUTION: This sound system for increasing sound pressure at a target position in a prescribed sound space more than the place around comprises a first speaker array composed of a plurality of speakers disposed along a first straight line, a second speaker array composed of a plurality of speakers disposed along a second straight line different from the first straight line and a sound supplying means for supplying a sound signal with corrected delay time to the first speaker array and each of the plurality of speakers constituting the first speaker array, wherein the first speaker array and the second speaker array are arranged around the sound space so as to make the first straight line intersect the second straight line on the same horizontal plane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an acoustic system, and more particularly to an acoustic system used indoors or outdoors such as a conference hall or an exhibition hall.

Conventionally, acoustic systems have been used to provide audio to viewers in indoor and outdoor spaces that can accommodate a plurality of viewers. Here, while listening to a specific viewer at a specific location, such as a spot in front of an exhibition at a museum or a museum, or in an exhibition booth at an exhibition hall, other people can hear this sound. There is known an acoustic system that prevents the sound from being heard (for example, Non-Patent Document 1). For example, in this acoustic system, a viewer wears an earphone to which a solar battery is connected. By irradiating light modulated by sound from the front of the exhibition, sound can be heard only from the earphones that have received this light.
Takuichi Nishimura, Hideo Ito, Yoshinobu Yamamoto, Hideyuki Nakajima, “Location-Based Information Support System Using Power-Free Small Communication Terminals”, IPSJ Intelligent Urban Infrastructure Research Group Research Report, 2002-ICII-2, pp. 1-6 (2002)

  However, in this configuration, the viewer has to wear a receiving device such as an earphone. As another acoustic system, there is an acoustic system that uses a parametric speaker to listen only to the viewer at a specific position, but the range of the target position where the sound can be heard has expanded linearly. It was.

  An object of the present invention is to provide an acoustic system capable of supplying sound only to a viewer who is in a range limited to a dotted shape without imposing a burden of wearing a device on the viewer. And

  In order to solve the above problems, the present invention provides the following.

  (1) An acoustic system (for example, the acoustic system 10) for increasing the sound pressure at a target position in a predetermined acoustic space from the surroundings, along a first straight line (for example, the first straight line 13). A first speaker array (for example, the first speaker array 22) including a plurality of speakers (for example, a plurality of speakers 12) to be arranged, and a second straight line (for example, a first straight line different from the first straight line) 2 straight line 15), a second speaker array (for example, second speaker array 24) composed of a plurality of speakers (for example, speaker 14), the first speaker array, and the first speaker array Audio supply means (for example, control device 42, D / A board 44, and step S1) for supplying an audio signal with a corrected delay time to each of a plurality of speakers constituting the speaker array 1 to S113), and delay calculation means (for example, the control device 42 and step S103) for calculating the delay time based on the distance between the target position and each of the plurality of speakers. The speaker system and the second speaker array are arranged around the acoustic space so that the second straight line and the first straight line intersect on the same horizontal plane.

  According to (1), the first speaker array and the second speaker array constituted by a plurality of speakers arranged along a straight line are arranged such that the straight lines intersect each other on the same horizontal plane. Thus, a range in which the sound pressure is higher than the surroundings, that is, a target position can be determined as a point on a plane in the acoustic space. Therefore, even if the viewer does not wear a special device, only the viewer standing at a specific spot (point) in the acoustic space can hear the sound. Further, since the delay time is calculated by the delay calculating means, the target position in the acoustic space can be dynamically changed without moving the speaker.

  (2) The acoustic system according to (1), wherein coordinate input means (for example, a control device 42, an input device 48, and step S101) for inputting coordinate data indicating a target position in the acoustic space; An acoustic system further comprising position display means (for example, the control device 42, the display device 52, and step S102) that displays an image of a target position in the acoustic space.

  According to (2), the acoustic system further includes coordinate input means for inputting coordinate data and position display means for displaying an image. As a result, it is possible to perform reliable coordinate setting such as inputting the target position by the coordinate input means while showing the image to the operator.

  (3) The acoustic system according to (2), wherein the coordinate input unit includes a pointing device.

  According to (3), the coordinate input means is configured using a pointing device. Thereby, the setting of the target position by an operator can be made easy.

  According to the present invention, a plurality of speaker arrays having a configuration in which a plurality of speakers are arranged along a straight line are arranged so that each straight line is adjacent to and intersects the acoustic space. As a result, a range in which the sound pressure is higher than the surroundings, that is, a target position can be determined as a point on the two-dimensional coordinate of the acoustic space. Therefore, only the viewer standing at a specific spot (point) in the acoustic space can hear the voice without the viewer wearing a special device. Moreover, since the delay time is calculated by the delay calculation means, the target position in the acoustic space can be dynamically changed.

  An acoustic system according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an acoustic system 10 according to the present embodiment. The acoustic system 10 provides sound information of music and voice only to a person in the range of the target position 30 by increasing the sound pressure at the target position 30 in the predetermined acoustic space 20 from the surroundings, It prevents people who are outside the range of 30 from listening to audio.

  The acoustic system 10 includes a plurality of speaker arrays 22, 24, and 26 each including eight speakers 12 a to 12 h (12), 14 a to 14 h (14), 16 a to 16 h (16), and 18 a to 18 h (18). , 28 and a personal computer system 40 connected to speakers 12, 14, 16, 18 via audio amplifiers 32, 34, 36, 38. The personal computer system 40 includes a D / A board (digital / analog conversion board) 44, and each of the speakers 12, 14, 16, and 18 is connected to the D / A board. In this figure, for convenience, connection wiring and audio amplifiers 32, 34, 36, and 38 are collectively displayed for each speaker array 22, 24, 26, and 28. The audio amplifiers 32, 34, 36, and 38 can adjust the sound pressure level output from the speakers 12, 14, 16, and 18 by performing power amplification and adjustment of the audio signal.

  The speakers 12, 14, 16, and 18 constituting the speaker arrays 22, 24, 26, and 28 are each arranged along a straight line. Specifically, in the speaker array 22 as the first speaker array, a plurality of speakers 12 are arranged along the first straight line 13. Further, in the speaker array 24 as the second speaker array, a plurality of speakers 14 are arranged along a second straight line 15 different from the first straight line. In the speaker array 26 as the third speaker array, a plurality of speakers 16 are arranged along another third straight line 17, and in the speaker array 28 as the fourth speaker array, a plurality of speakers 16 are arranged. The speaker 18 is arranged along another fourth straight line 19. Here, the first straight line 13, the second straight line 15, the third straight line 17, and the fourth straight line 19 are virtual lines. The speaker arrays 22, 24, 26, and 28 are arranged around the acoustic space 20 that is a range in which a target position can be set. The speaker arrays 22, 24, 26, and 28 are arranged so that the first straight line and the second straight line intersect on the same horizontal plane. More preferably, the first straight line, the second straight line, the third straight line, and the fourth straight line are arranged so as to intersect with any other straight line on the same horizontal plane. Furthermore, it is more preferable that the first straight line, the second straight line, the third straight line, and the fourth straight line are arranged so as to be orthogonal to one of the other straight lines on the same horizontal plane. The acoustic space 20 can be a room such as a conference room, a hall, or a museum exhibition room. In this case, the speaker arrays 22, 24, 26, and 28 are installed near the wall surface of the room or near the ceiling near the wall surface. Outside, the speaker array 22, 24, 26, and 28 is arranged to face the corner where the viewers gather as the acoustic space 20.

  Next, the configuration of the personal computer system 40 will be described. FIG. 2 is a diagram illustrating a hardware configuration of the personal computer system 40. The personal computer system 40 includes a control device 42 as a computer such as a CPU for executing various processes by executing a computer program, a mouse for inputting process control data based on an operator's operation, An input device 48 including a joystick and a keyboard; a storage device 50 such as a semiconductor memory or a disk device for storing computer programs and data necessary for realizing various processes; a CRT or LCD for displaying image data; A display device 52 in which a video card and a driver are combined with a printer, and an A / D converter for converting audio data and video data from the outside of the personal computer system 40 into digital data that can be processed by the control device 42. / A board (analog-digital conversion board) 46 and 128 channels of D / A converters for converting the audio data processed by the control device 42 into analog signals and outputting them to the speakers 12, 14, 16, 18 And a D / A board 44. These boards and devices are connected to each other by a bus and a connection interface. Each of the A / D board 46 and the D / A board 44 includes multi-channel converters, and these converters are all converted in synchronization with the same sampling clock or a clock obtained by multiplying or dividing the sampling clock ( It is desirable to perform conversion.

  The control device 42 realizes various corresponding means by performing the processing described later in cooperation with the above-described device according to the computer program. The computer program for processing executed by the control device 42 preferably operates as a process or task of a real-time OS such as ART-Linux (registered trademark). This facilitates audio data input / output and delay correction operations as real-time processing, and reduces problems such as discomfort and noise in the output audio. Here, data used or generated in various processes is read from the storage device 50 or stored in the storage device 50.

[Formation of sound field at target position]
Taking the speaker arrays 22 and 24 as an example, the formation of a sound field at a target position in the acoustic space 20 will be described. Sounds based on the same audio source are output from the speakers 12 and 14 constituting the speaker arrays 22 and 24. However, the audio signals supplied from the personal computer system 40 to the speakers 12 and 14 are subjected to delay processing based on different delay amounts. In the delay processing, for example, the audio data is recorded in a ring buffer provided in the storage device 50, while the data is read out at a place corresponding to data sampling for a time set for each speaker in the ring buffer, that is, It can be performed by reading out from the mutually shifted locations and outputting to the D / A board 44.

Here, the distances from the speakers 12 ( _{12a to 12h} ) and 14 ( _{14a to 14h} ) to the target positions are L _{12a to} L _12h and L _{14a to} L _14h , respectively. At this time, the delay times Δt _{12a to} Δt _12h and Δt _{14a to} Δt _14h corresponding to the speakers _{12a to 12h} and _{14a to 14h} , respectively,
Δt _12a = L _12a / speed of sound,
Δt _12b = L _12b / speed of sound,
...
Δt _12h = L _12h / speed of sound,
Δt _14a = L _14a / speed of sound,
Δt _14b = L _14b / speed of sound,
...
Δt _14h = L _14h / speed of sound,
The output of the audio data is delayed. Then, since the phase of the sound output from each speaker matches at the target position, the sound pressure increases. On the other hand, at a position other than the target position, the phase of the sound output from each speaker does not match and the sound waves cancel each other, so the sound pressure becomes small. In this way, the sound pressure at the target position in the predetermined acoustic space can be increased from the surroundings. Then, by adjusting the overall volume appropriately, only the person at the target position can hear the sound.

  In the speaker arrays 22 and 24 of the present embodiment, the speakers 12 and 14 are arranged along a straight line, respectively, but the speaker arrays 22 and 24 are arranged in such an orientation that the two straight lines intersect. Therefore, when the acoustic space, which is a space where these two straight lines face, is viewed from above, that is, from the ceiling of the room where the speaker array is installed, the range of the target position is limited to a dotted shape, and the directivity is further increased. . When there is one speaker array, it is difficult to increase the directivity in the direction perpendicular to the straight line on which each speaker is arranged. As a result, the sound pressure when moving back and forth from the target position toward the speaker. Can not be attenuated, and sound can be heard at the front and rear positions. In the speaker arrays 22 and 24 of the present embodiment, the target position that is in a range where the sound pressure is higher than that of the surroundings can be set as a narrow range as a point of the acoustic space. In this way, only the viewer who is at a specific spot (point) in the acoustic space can hear the voice without burdening the viewer to wear the device. Further, since the delay time is calculated by the personal computer system 40 (more specifically, the delay calculation process described later), the target position in the acoustic space can be dynamically changed.

[Operation example]
Here, an example of the operation of the acoustic system 10 will be described. FIG. 3 is an example of the display screen 52 a on the display device 52 of the acoustic system 10. The specific acoustic space 20 is displayed as a plan view on the display screen 52a. Here, a plan view image 60 of the conference hall serving as the acoustic space 20 is shown, and a coordinate axis image 62 serving as an index of coordinates in the acoustic space 20 is also displayed. In addition, a cursor 64 indicating a target position where the sound pressure is high in the acoustic space 20 is also displayed. In addition, an image 66 above the coordinates of the target position in the acoustic space 20 indicated by the cursor 64 is displayed on the upper right side of the display screen 52a.

  The plan view image 60 of the conference hall displays image data stored in the storage device 50 in advance and is an option. This is for visually and clearly showing the target position in the actual conference hall. The plan view image 60 of the conference hall is changed by the operation of the operator every time the object of the acoustic space 20 changes.

  In the acoustic system 10, when the operator operates the input device 48 such as a joystick, the target position is changed according to the operation. And according to this change, the position of the cursor 64 on the display screen 52a moves. As described above, the target position can be easily and dynamically moved by the processing in cooperation with the input device 48 and the display device 52. For example, when a target viewer who wants to supply audio moves within a conference hall or when the target viewer is changed to another person, the change can be easily performed.

[Control device processing]
Next, the processing of the control device 42 will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a flowchart showing processing by the control device 42. First, in step S101 (FIG. 4), the control device 42 performs a coordinate input process. Specifically, the control device 42 reads data indicating the coordinates of the target position from the input device 48. The content of the data is based on the result of the operator operating the input device 48 while looking at the display device. For example, the angle and time when the joystick as an example of the input device 48 is tilted. The input device 48 that performs input processing is preferably a pointing device such as a joystick or a mouse. Thereby, the setting of the target position by the operator can be facilitated. After the process of this step, the control device 42 proceeds to the process of step S102.

  In step S102, the control device 42 performs position display processing. Specifically, the control device 42 writes the image data illustrated in FIG. 3 stored in advance in the storage device on the display device 52 and displays the image. In this way, the target position can be input while showing the image to the operator. After the process of this step, the control device 42 proceeds to the process of step S103.

  In step S103, the control device 42 performs a delay calculation process. Specifically, the control device 42 reads the data indicating the coordinates of the target position once stored in the storage device 50, calculates all the distances from the 32 speakers 12, 14, 16, 18 and each of the distances. From the difference, the delay of the audio data output to each speaker 12, 14, 16, 18 is calculated. The calculation result data of the delay calculation process is stored in the storage device 50. After the process of this step, the control device 42 returns to the process of step S101.

  FIG. 5 is a flowchart showing still another process performed by the control device 42. This process is executed in parallel with the process shown in FIG. Since this processing needs to be executed in real time in synchronization with the sampling time of the D / A board 44, for example, it is registered as an independent process of the real-time OS or directly started as an interrupt processing. Is desirable.

  First, in step S111, the control device 42 performs a data read process. Specifically, the control device 42 reads a portion to be reproduced from, for example, audio data of an audio source stored in advance in the storage device 50. As other audio sources, for example, a microphone connected to the A / D board 46 or audio data obtained by sampling an audio signal from an audio reproduction device such as a DVD player by the A / D board 46, or control The voice data synthesized by the calculation of the device 42 can be used. In the process of this step, the control device 42 sets a ring buffer in the storage device 50, and stores the read data in this order sequentially. After the process of this step, the control device 42 proceeds to the process of step S112.

  In step S112, the control device 42 performs a delay correction process. Specifically, the control device 42 reads the delay calculation processing result data in step S103, and performs delay correction of the audio data output to the speakers 12, 14, 16, and 18 based on the result data. In the process of this step, the control device 42 sequentially reads out the audio data from the above-described ring buffer. At this time, the control unit 42 determines the audio data read position according to the delay time corresponding to each of the speakers 12, 14, 16, and 18. By shifting, a difference in delay is generated. After the process of this step, the control device 42 proceeds to the process of step S113.

  In step S113, the control device 42 performs data output processing. Specifically, the control device 42 writes the audio data read from the above-described ring buffer in the D / A board 44 in accordance with each of the speakers 12, 14, 16, and 18. As a result, a voltage value corresponding to the written data is output from the D / A board 44 as an audio signal. After the process of this step, the control device 42 ends the process.

  In addition, the process of each step implement | achieves the function of various means with the apparatus which cooperates and operate | moves.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this description.

  In the present embodiment, four speaker arrays 22, 24, 26, and 28 have been described. However, the present invention is not limited to this, and for example, two speaker arrays may be used. In this case, the two speaker arrays are preferably arranged at positions corresponding to the speaker arrays 22 and 24, for example, so that the straight lines of the speaker arrays intersect each other. Further, by using two speaker arrays as one set for one audio source of audio data, two audio sources are output by two sets of four speaker arrays. In this case, by setting a different target position for each set of speaker arrays, two target positions can be set in the acoustic space, and a different sound can be heard by the viewer at each target position.

  In the present embodiment, the number of speakers 12, 14, 16, and 18 constituting each of the speaker arrays 22, 24, 26, and 28 has been described as eight. However, the present invention is not limited to this, and an arbitrary plurality of speakers are provided. be able to. However, in order to improve the output directivity of sound waves, it is desirable that the number of speakers constituting one speaker array is four or more.

  In the present embodiment, the speakers 12, 14, 16, and 18 constituting the speaker arrays 22, 24, 26, and 28 are described as being arranged along a straight line. However, the straight lines are arranged in parallel. A plurality of straight lines. That is, the plurality of speakers constituting the speaker array may be arranged along a plane formed by a plurality of parallel straight lines. In this case, the target position in the acoustic space can extend the setting range in three dimensions.

  In the present embodiment, the display device 52 is an image display device. However, the display device 52 may be a projector with a drive that can electrically control the irradiation angle, for example. In this case, the driving angle of the projector is controlled so that the target position is illuminated. As a result, lighting is applied to a person who listens to the voice, and the voice and the lighting can be controlled simultaneously. In other words, in a conference hall or the like, it is possible to apply only voiced speakers to, for example, information such as the remaining time of speech by voice.

  As another embodiment different from the present embodiment, there is a sound collection system in which a speaker is used as a microphone in FIG. 1 and an A / D board is installed instead of the D / A board. In this system, a signal from each speaker is converted into audio data by an A / D board and sequentially input to a plurality of ring buffers corresponding to the speakers. In reading data from the ring buffer, the reading position is shifted for each speaker according to the difference in delay time calculated from the distance between each speaker and the target position, and all the data corresponding to each read speaker is added to D / Output from A board. With this configuration, only the sound component generated at the target position in the output audio data is increased by the addition. Therefore, according to this sound collection system, it is possible to selectively listen only to the remarks of a person at a specific position in a conference hall where an acoustic space is set.

1 is a schematic configuration diagram of an acoustic system 10 according to an embodiment of the present invention. It is a figure which shows the hardware constitutions of the personal computer system 40 which concerns on embodiment of this invention. It is a figure which shows the example of the display screen 52a in the display apparatus 52 which concerns on embodiment of this invention. It is a flowchart which shows the process by the control apparatus 42 which concerns on embodiment of this invention. It is a flowchart which shows another process by the control apparatus 42 which concerns on embodiment of this invention.

Explanation of symbols

10 acoustic systems 12a to 12h (12), 14a to 14h (14), 16a to 16h (16), 18a to 18h (18) speaker 20 acoustic space 22, 24, 26, 28 speaker array 30 target positions 32, 34, 36, 38 Audio amplifier 40 Personal computer system 42 Control device 44 D / A board 46 A / D board 48 Input device 50 Storage device 52 Display device 60 Plan view image 64 Cursor

Claims (3)

An acoustic system for increasing the sound pressure at a target position in a predetermined acoustic space from the surroundings,
A first speaker array comprising a plurality of speakers arranged along a first straight line;
A second speaker array comprising a plurality of speakers arranged along a second straight line different from the first straight line;
Audio supply means for supplying an audio signal with a corrected delay time to each of the first speaker array and the plurality of speakers constituting the first speaker array;
A delay calculating means for calculating the delay time based on a distance between the target position and each of the plurality of speakers;
The first speaker array and the second speaker array are arranged around the acoustic space so that the first straight line and the second straight line intersect on the same horizontal plane. system. The acoustic system according to claim 1,
Coordinate input means for inputting coordinate data indicating a target position in the acoustic space;
An acoustic system further comprising position display means for displaying an image of a target position in the acoustic space. The acoustic system according to claim 2,
The coordinate input means is an acoustic system comprising a pointing device.

Images