JP3242006B2 - Spot sound collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot sound collecting apparatus, and more particularly to a spot sound collecting apparatus suitable for selectively extracting a sound or the like emitted from a sound source separated by a specific distance.

[0002]

2. Description of the Related Art A microphone described in Japanese Patent Application Laid-Open No. Hei 7-135694 is an example of a device for selectively extracting a sound or the like generated by a specific sound source from a plurality of sound sources. In this microphone, when the sound source to be collected and the sound source not to be collected are in the same direction viewed from the observation position, it is difficult to selectively collect only sound waves coming from each sound source. It was done.

That is, in this microphone, based on the assumption that sound waves from a sound source at a short distance can be approximated as plane waves and sound waves from a sound source at a long distance can be approximated as spherical waves, only sound waves from a sound source near an observation position can be approximated. Is selectively collected.

[0004]

The above-mentioned conventional sound collecting device or microphone has the following problems.
That is, as described above, the above-described conventional microphone pays attention to the fact that the type of sound wave varies depending on the distance from the observation position. Therefore, it is not possible to detect a sound or the like from a specific sound source among a plurality of sound sources that are substantially equidistant from the observation position or at least have a positional relationship such that there is no difference in the type of the sound wave. There is a point.

[0005] In addition, voices from a specific sound source among a plurality of sound sources, for example, conversation of a specific person in crowds, sounds of animals in a zoo, and the like are separated and emphasized from surrounding sounds. There is a request to play. However, the conventional sound collecting device cannot meet such a demand.

An object of the present invention is to solve the above-mentioned problems and to provide a spot sound collecting apparatus capable of selectively extracting a sound from a specific sound source from among sounds emitted from a plurality of sound sources. And

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, the present invention provides at least two microphones and audio data storage means for storing audio data detected by each of the microphones. Generated by the sound source
Sound from the sound source to the farthest microphone
This time and the sound source
A time difference calculating means for detecting the difference between the time the sound reaches the microphone, the audio data from the microphones stored in the voice data storage unit to the time difference
A first feature is that there is provided audio data reading means for reading out with delay by a corresponding time difference, and synthesizing means for synthesizing the read audio data. A second feature is that a reproducing means for reproducing the audio data synthesized by the synthesizing means is provided, and a third feature is that an input means for externally inputting a distance from the sound source to each microphone is provided. There is a feature.

The present invention also provides a line-of-sight sensor, distance calculating means for calculating a distance between the line-of-sight sensor and a sound source based on the line-of-sight angle detected by the line-of-sight sensor, A fourth feature lies in that the input means is constituted by a distance calculating means for calculating a distance from the sound source to each microphone based on the set relative position of each microphone. A fifth feature of the present invention is that the present invention further includes an input unit for inputting atmospheric information for correcting sound velocity information used for calculating the time difference by the time difference calculating unit.

According to the first to fifth features, when reading out the sound data from the sound data storage means, the difference between the sound arrival time based on the distance between the sound source and the microphone and the sound detected by the microphone close to the sound source. Reads data with a delay. As a result, the sound emitted from the sound source is emphasized by the synthesizer and output from the reproducer.

According to the fourth feature, the distance from the sound source to the microphone can be detected based on the line-of-sight angle detected by the line-of-sight sensor and supplied to the voice data reading means. Further, according to a fifth feature, the time difference for reading audio data is determined by using atmospheric information, for example,
Correction can be made based on temperature, atmospheric pressure, humidity, and the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. First, an outline of the present embodiment will be described with reference to FIG. In the figure, a sound source SS is a person who is giving a lecture, a speech, a singing, etc. in, for example, a public hall, a hall, a plaza, and the like.
1 and M2 are arranged. The distances between the microphones M1 and M2 and the sound source SS are d1 and d2, respectively, and the microphones M1 and M2 are arranged so that the distances d1 and d2 are not equal to each other.

The times t1 and t2 until the sound emitted from the sound source SS reaches the microphones M1 and M2 arranged in such a positional relationship are obtained as quotients obtained by dividing the distances d1 and d2 by the sound speed c. That is, it can be calculated by the following equations (f1) and (f2). t1 = d1 / c ...
(F1), t2 = d2 / c (f2) In other words, the sound simultaneously emitted from the sound source SS is the time difference (Δt) between the times t1 and t2, and the microphone M
1 and M2. Therefore, the microphone M
1 and M2, the sound detected from the sound source SS whose distance to the sound source SS is short is delayed by the time difference Δt, and then synthesized with the sound detected by the other microphone to thereby obtain the sound from the sound source SS. Can be emphasized more than other sounds. That is, the ratio S / N between the voice S to be acquired and the other voice N can be increased.

Next, the configuration and operation of the sound collecting device according to the present embodiment will be described. FIG. 2 is a block diagram showing a hardware configuration of the sound collection device. In the figure, the arithmetic unit 1 has a CP
U2, ROM3, RAM4, operation panel 5, input interface 6, and output interface 7. The microphones M1 and M2 are connected to the input interface 6, and the speaker 8 is connected to the output interface 7. Reference numeral 9 denotes a bus.

With the above configuration, the user can operate the operation panel 5
Is used, distance information d1 and d2 for specifying the sound source SS from which sound is to be obtained are input. It is preferable that the operation panel 5 is configured so that atmospheric information such as temperature and pressure can be input as needed. Voices input from the microphones M1 and M2 through the input interface 6 are temporarily stored in the RAM 4 and processed according to a program stored in the ROM 5, and then output from the speaker 8 through the output interface 7.

Next, the main functions of the arithmetic unit 1 will be described. In the functional block diagram of FIG.
A / D converters 10 and 11 input audio from M1 and M2.
Is converted into digital audio information s1 and s2 by the RAM
4 is stored in the voice data storage unit 12.
The audio data reading unit 13 supplies the read clocks CL1 and CL2 to the audio data storage unit 12 and reads the digital audio information s1 and s2 to the synthesizing unit 14. The read clocks CL1 and CL2 have the same period, and are shifted in timing by the audio arrival time difference Δt due to the distances d1 and d2 between the microphones M1 and M2 and the sound source SS. That is, the read clocks CL1 and CL2 are such that the audio signal input from the microphone corresponding to the shorter one of the distances d1 and d2 is input to the synthesizer 14 after being delayed by Δt.
Adjust CL2.

The time difference Δt is calculated by the time difference calculation section 15. The time difference calculation unit 15 calculates the times t1 and t2 using the formulas (f1) and (f2) based on the distance information d1 and d2 input from the operation panel 5, and further calculates the difference between the times t1 and t2. That is, Δt is calculated.

Since the sound speed c varies depending on atmospheric conditions such as temperature, humidity, and atmospheric pressure, the sound speed c can be calculated under these atmospheric conditions so that the time difference Δt can be calculated more accurately and the sound can be processed.
Is desirably corrected. The atmospheric conditions can be input from the operation panel 5. Alternatively, a thermometer, a hygrometer, a pressure gauge, or the like may be connected to the time difference calculation unit 15 so that the atmospheric conditions can be directly and automatically read.

The synthesizing section 14 synthesizes digital audio information read from the audio data storage section 12 and inputs the synthesized information to the data conversion section 16. Data conversion unit 1
6 converts the digital audio information into a signal suitable for a reproducing apparatus such as a speaker 8 or an earphone and outputs the signal to the speaker 8. The data conversion unit 16 includes the output interface 7
Can be included. The information synthesized by the synthesizing unit 14 is not limited to being directly reproduced by the reproducing apparatus, but may be input to a recording means such as a tape recorder or a ROM. In the above-described example, the sound source SS is specified by inputting the distance information from the operation panel 5. This example is suitable when the distance between the sound source and the observation position, that is, the microphone can be measured in advance. However, in a situation where it is difficult to measure the distance in advance, for example, when extracting a sound from a moving sound source, the above example is not optimal.

Therefore, in a modified example described below, it is possible to extract a sound from a moving sound source or a sound source whose distance is unknown. FIG. 4 is a perspective view illustrating a configuration of a sound collection device according to a modification, and FIG. 4B is a plan view of a main part. In FIG. 4, the lens unit 18 of the goggle 17
Line-of-sight sensors 19a and 19b are provided on a and 18b, and microphones M1 and M2 are mounted on the frame section 20 of the goggles 17. The eye-gaze sensing sensors 19a and 19b can be configured as follows. For example, an LED and a CCD are provided, and light emitted from the LED is
The goggles 17 are configured to be reflected by an eyeball of a person wearing the goggles 17, and the reflected image can be captured by the CCD. The reflected image is processed by a computer to detect the angle of the eyeball, that is, the line of sight. This line-of-sight sensor 1
The line of sight of both eyes is detected by 9a and 19b, and the distance d to the sound source SS to which the line of sight is directed can be calculated based on the line of sight, that is, the line-of-sight angles α1 and α2. The line-of-sight sensor is described in “Development of Line-of-Sight Input AF of Single-Lens Reflex Camera” published in 1993 by the Photographic Society of Japan, Vol. 56, No. 5, pp. 369-371.

Furthermore, if the relative positional relationship between the microphones M1 and M2 and the line-of-sight sensors 19a and 19b is set in advance, the microphones M1 and M2 and the sound source SS are determined based on the relative positional relationship and the distance d. Distance d
1, d2 can be calculated. The distances d1, d
The positions of the microphones M1 and M2 are determined so that 2 differs from each other. For example, from the point m on the extension of the midpoint of the line-of-sight sensors 19a and 19b, the microphone M
Either the distances L1 and L2 to M1 and M2 are different, or the microphones M1 and M2 are shifted and arranged in the direction of the sound source SS.

The above configuration and operation will be described with reference to the functional block diagram of FIG. In the figure, the same symbols as those in FIG. 1 indicate the same or equivalent parts. Eye-gaze sensing sensor 19a,
The line of sight detected at 19b, that is, the angles α1 and α2 are input to the distance calculation unit 21. The distance calculation unit 21 calculates the angle α1,
The distances d1 and d2 are calculated based on α2 and the distance between the eye-gaze sensing sensors 19a and 19b. The calculated distances d1 and d2 are supplied to the time difference calculation unit 15. later,
As described above, the time difference Δt can be calculated by the time difference calculation unit 15, and the output timing of the clocks CL1 and CL2 is determined. In the time difference calculating section 15, data indicating the relative positional relationship between the microphones M1 and M2 and the eye-gaze sensing sensors 19a and 19b, such as the distances L1 and L2, necessary for calculating the time difference Δt is set in advance. deep.

Next, the processing for calculating the time difference Δt will be described with reference to the flowchart of FIG. In the figure, in step S1, the line-of-sight sensing sensors 19a, 19b
The angles α1 and α2 detected in step 2 are read. Step S2
Then, the distance d to the sound source SS is calculated based on the angles α1, α2 and the distance between the line-of-sight sensors 19a and 19b. In step S3, L1 and L2 are read. In step S4, distances d1 and d2 are calculated based on distances L1 and L2 and distance d. In step S5, the expression (f)
1) and (f2) are used to calculate times t1 and t2, and step S
In step 6, the time difference Δt, that is, the absolute value of (t1−t2) is calculated.

In the above-described modification, the microphone and the line-of-sight sensor are mounted on the goggles. However, the microphone does not necessarily have to be installed integrally with the line-of-sight sensor. The point is that the relative positional relationship between the eye-gaze sensing sensor and the microphone may be determined in advance. For example, a microphone is arranged at a predetermined location in a zoo cage, and an animal is observed by wearing goggles including a line-of-sight sensor at an observation position in which the positional relationship with the microphone is fixed. Then, the sound emitted from the target animal pursued from the observation position with the eyes can be emphasized and output from the speaker. The measurement of the distance is not limited to the above-described line-of-sight sensor, but can be performed by a well-known distance measuring unit.

In this embodiment, the case where two microphones are used has been described. However, by adding more microphones, it is possible to extract a sound from a sound source specified by a distance from the three or more microphones. Can be. That is, when three or more microphones are used, the time difference from the other microphones is calculated for each microphone based on the microphone located farthest from the sound source, and the timing is shifted according to each time difference. The audio data is read from the audio data storage unit and synthesized by the synthesizing unit.

[0025]

As is apparent from the above description, according to the first to fifth aspects of the present invention, it is possible to emphasize and extract a sound generated from a sound source specified by a distance from a plurality of microphones. it can. In particular, according to the invention of claim 4, the distance from the line-of-sight sensor to the sound source can be detected based on the line-of-sight angle detected by the line-of-sight sensor.
Therefore, by previously determining the relative positional relationship between the eye-gaze sensing sensor and the microphone, it is possible to emphasize and extract the sound from the sound source recognized by the human eye.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating main functions of a sound collection device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a hardware configuration of the sound collection device according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an outline of a sound collection device according to an embodiment of the present invention.

FIG. 4 is a schematic diagram showing a distance measuring device of a sound collecting device according to a modification of the embodiment of the present invention.

FIG. 5 is a functional block diagram of a main part of a modified example.

FIG. 6 is a flowchart showing an operation of a main part of the sound collection device.

[Explanation of symbols]

1: arithmetic unit, 5: operation panel, 8: speaker,
12 audio data storage unit 13 audio data reading unit
14: synthesis unit, 15: time difference calculation unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-327097 (JP, A) JP-A-54-76128 (JP, A) JP-A-59-41995 (JP, A) JP-A-59-1995 83496 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04R 1/20-1/40 H04R 3/00

Claims (5)

(57) [Claims] At least two microphones, audio data storage means for storing audio data detected by each of the microphones, and a microphone generated by a sound source at a farthest distance from the sound source
Based on the time to reach the crophone,
The time that the sound arrives from the sound source to each microphone
A time difference calculating means for detecting a difference between the voice data reading means for reading the voice data from the microphone is stored in the voice data storage means with a delay time difference corresponding to the time difference, the read out voice A spot sound collecting device, comprising: synthesizing means for synthesizing data. 2. A method according to claim 1, characterized by comprising a reproducing means for reproducing the audio data synthesized by said synthesizing means
The spot sound collector according to the above. 3. The spot sound collecting apparatus according to claim 1, further comprising an input unit for externally inputting a distance from the sound source to each of the microphones. 4. The line-of-sight sensor, a distance calculator that calculates a distance between the line-of-sight sensor and a sound source based on a line-of-sight angle detected by the line-of-sight sensor, 4. The spot sound collecting apparatus according to claim 3 , further comprising distance calculating means for calculating a distance from the sound source to each microphone based on a preset relative position of each microphone. 5. An apparatus according to claim 1, further comprising input means for inputting atmospheric information for correcting sound velocity information used for calculating the time difference by said time difference calculating means.
5. The spot sound collecting device according to any one of items 1 to 4.