WO2014199446A1 - マイクロホン装置 - Google Patents
マイクロホン装置 Download PDFInfo
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- WO2014199446A1 WO2014199446A1 PCT/JP2013/066105 JP2013066105W WO2014199446A1 WO 2014199446 A1 WO2014199446 A1 WO 2014199446A1 JP 2013066105 W JP2013066105 W JP 2013066105W WO 2014199446 A1 WO2014199446 A1 WO 2014199446A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
- H04R3/005—Circuits for transducers, loudspeakers or microphones for combining the signals of two or more microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
- H04R1/40—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
- H04R1/406—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
- H04R2201/40—Details of arrangements for obtaining desired directional characteristic by combining a number of identical transducers covered by H04R1/40 but not provided for in any of its subgroups
- H04R2201/403—Linear arrays of transducers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
- H04R2201/40—Details of arrangements for obtaining desired directional characteristic by combining a number of identical transducers covered by H04R1/40 but not provided for in any of its subgroups
- H04R2201/405—Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2203/00—Details of circuits for transducers, loudspeakers or microphones covered by H04R3/00 but not provided for in any of its subgroups
- H04R2203/12—Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2430/00—Signal processing covered by H04R, not provided for in its groups
- H04R2430/20—Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic
- H04R2430/21—Direction finding using differential microphone array [DMA]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2430/00—Signal processing covered by H04R, not provided for in its groups
- H04R2430/20—Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic
- H04R2430/23—Direction finding using a sum-delay beam-former
Definitions
- the present invention relates to a microphone device using a microphone array composed of a plurality of microphones.
- Patent Document 1 An example of a microphone array formed by arranging a plurality of microphones on an array is disclosed in Patent Document 1.
- the first and second microphones are arranged with a predetermined distance D therebetween.
- a third microphone is disposed between the first and second microphones at a position D / 2 from the first and second microphones.
- a fourth microphone is disposed at a position D / 4 from the first and third microphones.
- a fifth microphone is disposed between the fourth and third microphones at a position D / 8 from the third and fourth microphones.
- a sixth microphone is disposed at a position D / 16 from the third and fifth microphones at the bottom of the fifth and third microphones.
- a seventh microphone is disposed between the sixth microphone and the third microphone at a position D / 32 from the third and sixth microphones.
- An eighth microphone is disposed between the seventh and third microphones at a position D / 64 from the third and sixth microphones.
- the sound signals from the microphones that make up these microphone units are processed by beam forming. That is, the first to third microphones constitute a first microphone unit, the first, fourth, and third microphones constitute a second microphone unit, and the third to fifth microphones constitute a third microphone unit.
- the third, fifth, and sixth microphones constitute a fourth microphone unit, the third, sixth, and seventh microphones constitute a fifth microphone unit, and the third, The seventh and eighth microphone units constitute a sixth microphone unit.
- the audio signals from the first and second microphones are multiplied by a coefficient of 0.5
- the audio signal from the third microphone is multiplied by a coefficient of 1, and the first to the multiplied first coefficients.
- the synthesized signal is generated by synthesizing the audio signal from the third microphone by the synthesizing means. Similarly, in the second to sixth microphone units, the sound signal from the microphones at both ends of the microphones constituting each microphone unit is multiplied by a coefficient of 0.5, and the sound signal from the center microphone is multiplied by a coefficient of 1. The combined signal is generated. By recombining these synthesized signals, the microphone device has a sharp directivity over a wide frequency band. In addition, the sound signal of each microphone is delayed by a delay circuit and supplied to the beam forming unit.
- the fourth to eighth microphones are arranged between the first and third microphones, and only the second microphone is the first and third microphones. Located away from between the microphones.
- the center of the sound collection of each microphone unit varies, and as a result, the sound collection of the speaker's sound standing in front of the microphone array is biased.
- the sound collection center of the first microphone unit is the arrangement position of the third microphone in the center
- the sound collection center of the second microphone unit is the arrangement position of the fourth microphone
- the sound collection center of the microphone unit is the arrangement position of the fifth microphone
- the sound collection center of the fourth microphone unit is the arrangement position of the sixth microphone
- the sound collection center of the fifth microphone unit is the seventh collection position.
- the sound collection center of the sixth microphone unit is the position of the eighth microphone. Then, the sound collection centers of the microphone units are dispersed with respect to the length direction of the entire microphone array. Furthermore, the sound collection centers of the respective microphone units are scattered at positions deviated to the left from the center position in the length direction of the microphone array (arrangement position of the third microphone). Since each microphone unit has the characteristic of collecting sound most efficiently near the sound collecting center, for example, when a speaker is speaking between the third to fourth microphones, many microphones are placed in front of the speaker. Since the sound collection center of the unit exists, sound collection is performed satisfactorily, but when the speaker is speaking between the second and third microphones, sound collection cannot be performed well. Although the directivity direction can be controlled by delaying the sound signal of each microphone by the delay circuit, it is necessary to give a large delay only when the speaker is speaking between the second and third microphones. Yes, the sound collection characteristics of the entire microphone array are affected.
- An object of the present invention is to prevent the sound collection centers of each microphone from being dispersed as much as possible in the length direction of the microphone array in the microphone array device.
- the microphone device of one embodiment of the present invention has a microphone array.
- the microphone array includes n (n is a positive integer of 3 or more) sets of microphone units.
- the first set of microphone units is formed by arranging three microphone units in a line at equal intervals.
- the mth (1 ⁇ m ⁇ n positive integer) set of microphone units includes microphones at both ends of the (m ⁇ 1) th microphone unit, and is approximately equal to the distance between the microphones at both ends of the (m ⁇ 1) th microphone unit.
- a microphone located on the opposite side of the microphone at the other end from the microphone at one end of the m ⁇ 1th microphone unit with a distance therebetween is included.
- the m + 1th microphone unit includes microphones at both ends of the mth microphone unit, and a microphone at the other end of the mth microphone unit is separated by a distance approximately equal to the distance between the microphones at both ends of the mth microphone unit. Therefore, a microphone located on the opposite side of the microphone at one end across the microphone at the other end is included.
- the voice signals collected and generated by the microphones of the respective microphone units are synthesized and the synthesis means outputs the synthesized signal.
- the sound signal from the microphones at both ends of the microphone unit is multiplied by a predetermined coefficient by multiplication means, and the sound signal of the central microphone unit has a coefficient larger than the predetermined coefficient, for example, a predetermined coefficient.
- the multiplication means multiply the coefficient twice as large as the above and the synthesized voice signal is synthesized by the synthesis means.
- the synthesized signal output from these synthesizing means is re-synthesized by the re-synthesizing means.
- the sound signal of each microphone can be supplied to each multiplication means after being delayed by the delay means.
- the delay amount of the delay means is adjusted so that the delay generated in the sound signal of each microphone matches the distance difference between the sound source to be collected by each microphone and each microphone.
- each microphone positioned in the center of each microphone unit are alternately positioned on both sides of the center microphone of the first set of microphone units.
- each microphone is not arranged in a concentrated manner between two specific microphones, but is arranged on both sides of the central microphone of the first set of microphone units, resulting in the sound collection center of each microphone unit. Are collected near the position of the microphone at the center of the first set of microphone units. .
- a microphone other than the microphone of the nth microphone unit among the microphones, and the distance to any of the microphones at both ends of the nth microphone unit is n
- the microphone that is longer than the distance between the microphones of the first microphone unit can be used as the central microphone of the (n + 1) th microphone unit.
- a microphone whose distance to the center microphone of the (n + 1) th microphone unit is longer than the distance between the microphones of the nth microphone unit is used. Use a microphone at the end.
- the center microphone of the (n + 1) th microphone unit is sandwiched between the microphones at the end of the (n + 1) th microphone unit and the distance between the center and end microphones of the (n + 1) th microphone unit is approximately equal to the distance between them.
- the microphone at the other end of the (n + 1) th microphone unit is arranged.
- the audio signals collected and generated by the microphones of the (n + 1) th microphone unit are synthesized by a new synthesizing unit and supplied to the re-synthesizing unit.
- the microphone is a microphone other than the microphone of the nth microphone unit, and the distance between the microphones at both ends of the nth microphone unit is longer than the distance between the microphones of the nth microphone unit.
- this microphone is the sound collection center of the (n + 1) th microphone unit located on the outermost side.
- the center microphone of the other microphone unit is also in the vicinity of the center microphone of the (n + 1) th microphone unit.
- the distance between the microphone at the other end of the (n + 1) th microphone unit newly added to form the (n + 1) th microphone unit and the microphone at the center of the (n + 1) th microphone unit is the both ends of the nth microphone unit. Shorter than the distance between the microphones. Therefore, the length of the microphone array can be shortened, and the microphone device can be miniaturized.
- each microphone may have a microphone element inside the case.
- the case is embedded in the microphone installation section so that the element is substantially in contact with the microphone installation section.
- the microphone can be a unidirectional microphone. In that case, each microphone directs its directivity in the same direction.
- the substrate on which each of the combining means and the re-synthesizing means is provided can be tilted with respect to the microphone array.
- the microphone array can be arranged in a housing.
- the walls of the casing are located on both outer sides of both ends of the microphone array, and these walls are inclined with respect to the microphone array.
- each microphone can be a unidirectional microphone. In that case, each microphone has the directivity direction in the same direction.
- FIG. 1 is a partially omitted plan view of a microphone array of a microphone device according to an embodiment of the present invention.
- FIG. 2 is a perspective view of the microphone device according to the embodiment of the present invention.
- FIG. 3 is a vertical side view of the microphone device of FIG.
- FIG. 4 is a partially omitted front view of the microphone device of FIG. 2 with the cover removed.
- FIG. 5 is a cross-sectional view taken along line 5-5 of FIG.
- FIG. 6 is a block diagram of the microphone device of FIG.
- FIG. 7 is a detailed block diagram of the beamforming unit of FIG. It is a frequency characteristic figure of the microphone apparatus of FIG.
- the microphone device 2 is attached to the longitudinal edge of the top 6 of the podium 4 where the speaker stands as shown in FIG.
- the microphone device 2 has a housing 8.
- the casing 8 is in the shape of a long and narrow box having an upper opening, and one longitudinal edge thereof is arranged along the longitudinal edge of the top plate 6.
- a cover 10 is attached to the upper opening of the housing 8.
- the housing 8 has a microphone installation portion, for example, a rectangular bottom wall 12.
- a plurality of, for example, eight first to eighth microphones (MICs) 14-1 to 14-8 are arranged along the other longitudinal edge of the bottom wall 12 on the speaker side opposite to the top plate 6. Arranged as shown in FIG. 1, a microphone array is configured. These first to eighth microphones 14-1 to 14-8 are, for example, unidirectional microphones. The first to eighth microphones 14-1 to 14-8 are arranged so that their directivity directions are orthogonal to the longitudinal edge of the bottom wall 12 and face the speaker. These first to eighth microphones 14-1 to 14-8 have, for example, a cylindrical case 16 as shown in FIG. 3, and are arranged so that one end of the case 16 faces the speaker side. An opening 18 for introducing voice is formed at this end.
- MICs first to eighth microphones
- a microphone element 20 is arranged inside the case 16 so as to face the speaker side.
- the microphone element 20 is disposed in the case 16 so that the center thereof coincides with the center of the opening 18. Further, as shown in FIGS. 3 and 5, a plurality of, for example, four through holes 22 are formed at the other end of the case 16.
- the first to eighth microphones 14-1 to 14-8 have a case 16 embedded in the bottom wall 12 so that the opening 18 is in contact with the upper surface of the bottom wall 12. Since the speaker's head is usually located above the top plate 6, the sound from the speaker comes from obliquely above the microphones 14-1 to 14-8. If the case 16 is attached to the bottom wall 12 so that the opening 18 is located above the upper surface of the bottom wall 12, the voice of the speaker directly reaches the microphone element 20 from the opening 18 and the bottom wall. The sound reflected by the upper surface of 12 reaches the microphone element 20 through the opening 18. In this case, the voice that has arrived directly may be interfered with the voice that has arrived by reflection, leading to a reduction in sound quality. In order to prevent this, the opening 18 is in contact with the upper surface of the bottom wall 12 as described above. As a result, as shown by the arrow a in FIG. 3, the sound reflected by the bottom wall 12 is less likely to enter the case 12 through the opening 18.
- the first microphone 14-1 is disposed approximately at the center of the bottom wall 12 in the length direction.
- the second microphone 14-2 is disposed at a position away from the first microphone 14-1 by a predetermined distance d.
- the third microphone 14-3 is located on the opposite side of the first microphone 14-1 with the second microphone 14-2 interposed therebetween by the distance d.
- the first to third microphones 14-1 to 14-3 position the second microphone 14-2 in the center, and the first and third microphones 14- and 14-3 are located on both sides of the second microphone 14-2.
- a first set of microphone units is configured.
- the first microphone 14-1 and the third microphone 14-3 are separated by a distance 2d.
- a fourth microphone 14-4 is arranged away from the third microphone 14-3 by this distance 2d and on the opposite side of the first microphone 14-1 with the first microphone 14-1 interposed therebetween.
- the first, third, and fourth microphones 14-1, 14-3, and 14-4 position the third microphone 14-3 at the center, and the first and fourth microphones 14-1 on both sides thereof.
- the fourth microphone 14-4 and the first microphone 14-1 are located at a distance of 4d as is apparent from FIG.
- the fifth microphone 14-5 is located away from the first microphone 14-1 by this distance 4d, and on the opposite side of the fourth microphone across the first microphone 14-1.
- the first microphone 14-1 is located at the center, and the fourth and fifth microphones 14-4 are arranged on both sides thereof.
- the fifth microphone 14-5 and the fourth microphone 14-4 are located at a distance of 8d as is apparent from FIG.
- a sixth microphone 14-6 is disposed away from the fourth microphone 14-4 by this distance 8d and on the opposite side of the fifth microphone 14-5 with the fourth microphone 14-4 interposed therebetween.
- the fourth microphone 14-4 is located in the center, and the fifth and sixth microphones 14-5 are arranged on both sides thereof.
- And 14-6 are located in a fourth set of microphone units.
- the distance between the fifth microphone 14-5 and the sixth microphone 16 is separated by a distance 16d as is apparent from FIG.
- a seventh microphone 14-7 is arranged on the opposite side of the sixth microphone 14-6 with the fifth microphone 14-5 being sandwiched away from the fifth microphone 14-5 by a distance of 16d.
- the fifth microphone 14-5 is located in the center, and the sixth and seventh microphones 14-6 are arranged on both sides thereof. And 5-7 sets of microphone units in which 14-7 are located.
- the second microphone 14-2 which is the center microphone of the first microphone unit
- the third microphone 14-3 which is the center microphone of the second set of microphone units
- the second microphone 14-2 which is the center microphone of the first set of microphone units
- the first microphone 14-1 which is the center microphone of the third set of microphone units
- the fourth microphone 14-4 which is the center microphone of the fourth set of microphone units
- the fifth microphone 14-5 which is the center microphone of the fifth set of microphone units, is located on the left side of the second microphone 14-2, which is the center microphone of the first set of microphone units, and 3 It is located on the left side of the first microphone 14-1, which is the central microphone of the microphone unit of the set.
- the microphones at the center of the second and subsequent microphone units are alternately positioned on both sides of the microphone at the center of the first microphone unit.
- the third microphone 14-3 in FIG. The remaining five microphones are arranged between the corresponding microphone and the microphone corresponding to the seventh microphone 14-7, and the microphone corresponding to the third microphone 14-3 is completely positioned on the right side in FIG. Is not placed.
- a fourth microphone 14-4 and a sixth microphone 14-6 are also arranged on the right side of the third microphone 14-3 in FIG.
- the arrangement of the microphones of the second to fifth microphone units is a total of n (5 in this embodiment) microphone units, and m (1 ⁇ m ⁇ n) of the microphone units.
- the microphone unit includes microphones at both ends of the m ⁇ 1th microphone unit, and is separated by a distance approximately equal to the distance between the microphones at both ends of the m ⁇ 1th microphone unit.
- a microphone located on the opposite side of the microphone at the other end from the microphone at the other end is included from the microphone at the end.
- the m + 1th microphone unit includes microphones at both ends of the mth microphone unit, and a microphone at the other end of the mth microphone unit is separated by a distance approximately equal to the distance between the microphones at both ends of the mth microphone unit.
- a microphone located on the opposite side of the microphone at one end across the microphone at the other end is included.
- the number of all microphone units is not limited to five, and can be any positive integer as long as it is three or more.
- m is (a positive integer where 1 ⁇ m ⁇ n).
- the one side is the right side of the second microphone 14-2 and the other side is the left side of the second microphone 14-2.
- the left side of the microphone 14-2 may be the right side of the second microphone 14-2.
- a sixth set of microphone units is also provided. If the sixth microphone unit is configured in the same manner as the second to fifth microphone units, the sixth microphone 14-6 has a distance of 32d between the seventh microphone 14-7 and the sixth microphone 14-6. In addition, the eighth microphone 14-8 is arranged on the opposite side of the seventh microphone 14-7 with the sixth microphone 14-6 interposed therebetween. In this way, the sixth set of microphone units includes the seventh microphone 14-7, the sixth microphone 14-6, and the eighth microphone 14-8. However, with such an arrangement, the sound collection centers of the first to sixth microphone units are deviated from the center in the length direction of the microphone array to the one (left side in FIG. 1).
- the position of the sixth microphone 14-6 located at the center of the microphones constituting the sixth set of microphone units located on the outermost side is the center position in the length direction of the microphone array. Become. Then, the sound collection centers of one to five sets of microphone units are biased to one side (left side in FIG. 1) from the center position in the length direction of the microphone array.
- the fifth microphone 14 that is a microphone used in the first to fourth microphone units excluding the fifth microphone unit that is the latest microphone unit among the first to fifth microphone units formed so far. -5, the first microphone 14-1, the second microphone 14-2, the third microphone 14-3, and the fourth microphone 14-4, which constitute a microphone unit with the seventh microphone 14-7 Any of the first microphone 14-1, the second microphone 14-2, the third microphone 14-3, or the fourth microphone 14-4, and the fifth microphone unit.
- the sixth and seventh microphones 14-6 and 14-7 which are microphones at both ends of the 6 sets of microphones longer than the distance 16d between the fifth, sixth and seventh microphones 114-5, 14-6 and 14-7 of the fifth microphone unit, for example, the third microphone 14-3.
- the third microphone 14-3 is separated from the third microphone 14 by a distance 22d between the third microphone 14-3 and the seventh microphone 14-7.
- the eighth microphone 14-8 is arranged.
- the distance between the seventh microphone 14-7 and the eighth microphone 14-8 is 44d, which is shorter than the distance 64d, and the first to eighth microphones 14-1 to 14-.
- the microphone array composed of 8 can be reduced in size, and the sound collection positions of the microphone units can be concentrated near the center of the length direction of the microphone array. That is, with such an arrangement, the sound collection center of the sixth set of microphone units located on the outermost side becomes the position of the third microphone 14-3, whereby the center position of the entire microphone array becomes the third microphone 14-. 3 position.
- the sound collection center of the first set of microphone units position of the second microphone 14-2
- the sound collection center of the second set of microphone units third microphone 14.
- the sound collection center of the third set of microphone units position of the first microphone 14-1
- the sound collection center of the fourth set of microphone units position of the fourth microphone 14-4
- the sound collection center of the fifth set of microphone units position of the fifth microphone 14-5)
- the sound collection center of the sixth set of microphone units position of the third microphone 14-3) are all in the microphone array. They are gathered together in the vicinity of the overall center position (position of the third microphone 14-3).
- the first or second microphone 14-1 or 14-2 may be used as the center microphone of the sixth set of microphone units. If the microphone array may be larger than the microphone array of this embodiment, the fourth microphone 14-4 may be the center microphone of the sixth set of microphone units.
- the sixth set of microphone units in order to form the (n + 1) th microphone unit, microphones other than the microphones of the nth microphone unit among the microphones, and the nth microphone unit
- the microphone whose distance to any of the microphones at both ends of the microphone is longer than the distance between the microphones of the nth microphone unit is the microphone at the center of the (n + 1) th microphone unit, and among the microphones at both ends of the nth microphone unit
- a microphone whose distance to the center microphone of the (n + 1) th microphone unit is longer than the distance between the microphones of the (n + 1) th microphone unit is defined as the microphone at the end of the (n + 1) th microphone unit.
- the n + 1th microphone unit is located at a position approximately equal to the distance between the microphones at the center and the end of the (n + 1) th microphone unit.
- a microphone at the other end of the microphone unit is arranged.
- the first to eighth microphones 14-1 to 14-8 generate voice signals corresponding to the voices of the speakers. These voice signals are supplied to the first to eighth microphones 14 as shown in FIG. -1 to 14-8 are supplied to directivity adjusting means, for example, the beam forming unit 26, via variable delay means provided corresponding to -1 to 14-8, for example, variable delay circuits 24-1 to 24-8. The functions of the variable delay circuits 24-1 to 24-8 will be described later. In the following description of the beam forming 26, the variable delay circuits 24-1 to 24-8 are ignored.
- processing of an audio signal from the microphone constituting the microphone unit is performed. That is, audio signals from two microphones located on both sides of the three microphones constituting the microphone unit are multiplied, for example, amplified by a predetermined coefficient, for example, 0.5 by a multiplying unit, for example, an amplifier.
- the sound signal from the microphone located at the center is multiplied, for example, amplified by a multiplying unit, for example, an amplifier, with a coefficient larger than the predetermined coefficient, for example, 1 that is twice.
- Each of these multiplied, eg amplified, audio signals is synthesized, eg, added, by a synthesis means, eg, an adder.
- directivity becomes sharp at a frequency determined by the distance between the microphones constituting the microphone unit.
- audio signals from the microphones 14-1 and 14-3 on both sides are amplified by the amplifiers 28-1 and 28-2 whose gains are adjusted to 0.5, respectively.
- the audio signal of the microphone 14-2 at the center of the first set of microphone arrays is amplified by the amplifier 28-3 whose gain is adjusted to 1.
- the output signals of these amplifiers 28-1 to 28-3 are added by an adder 30-1.
- the output signal of the adder 30-1 exhibits a sharp directivity at a frequency f1 determined by the distance d between the microphones of the first microphone unit.
- the audio signals from the microphones 14-1 and 14-4 on both sides are amplified by the same amplifiers 28-21 and 28-22 as the amplifiers 28-1 and 28-2,
- the audio signal from the center microphone 14-4 is amplified by the amplifier 28-5 having the same configuration as that of the amplifier 28-23 and added by the adder 30-2.
- the output signal of the adder 30-2 exhibits a sharp directivity at a frequency f2 (f1> f2) determined by the distance 2d between the second microphones.
- the audio signals of the third to sixth microphone units are the amplifiers 28-31, 28-32, 28-33, 28-41, 28-42, 28-43, 28-51, 28-52, 28-53, 28-61, 28-62 and 28-63 and adders 30-3 to 30-6.
- the output signals of the adders 30-3 to 30-6 corresponding to the third to sixth microphone units are frequencies f3 to f6 (f3> f4> f5> determined by the distances 3d, 4d, 8d, 16d and 22d. Each of f6) shows a sharp directivity.
- the audio signals of the microphones 14-7 and 14-8 on both sides of the sixth set of microphone units are multiplied by a predetermined coefficient, for example, 1 by multiplication means, for example, amplifiers 28-71 and 28-72, for example, amplified.
- the output signals of these amplifiers 28-71 and 27-72 are combined, for example, added by a combining means, for example, an adder 30-7.
- the output signal of the adder 30-7 is determined by the distance 44d between the seventh and eighth microphones 14-7 and 14-8. Sharp directivity is shown at a frequency f7 (f6> f7).
- the output signal of the adder 30-1 is supplied to extraction means, for example, a high pass filter (HPF) 30-1.
- the high-pass filter 30-1 uses a frequency set lower than the frequency f1 as a cutoff frequency, and extracts a frequency component higher than the cutoff frequency from the output signal of the adder 30-1.
- the output signal of the adder 30-2 is supplied to extraction means, for example, a band pass filter (BPF) 30-2.
- BPF band pass filter
- the band pass filter 30-2 adds a frequency component higher than the frequency f2, for example, a band component having a cutoff frequency of the high pass filter 30-1 as an upper limit frequency and a predetermined frequency between the frequency f2 and the frequency f3 as a lower limit frequency. Extracted from the output signal of the device 30-2.
- the bandpass filter 30-3 has a frequency higher than the frequency f3, for example, a passband having a lower limit frequency of the bandpass filter 30-2 as an upper limit frequency and a predetermined frequency between the frequency f3 and the frequency f4 as a lower limit frequency.
- the bandpass filter 30-4 has a frequency higher than the frequency f4, for example, a passband having a lower limit frequency of the bandpass filter 30-3 as an upper limit frequency and a predetermined frequency between the frequency f4 and the frequency f5 as a lower limit frequency.
- the bandpass filter 30-5 has a higher frequency than the frequency f5, for example, a passband having a lower limit frequency of the bandpass filter 30-4 as an upper limit frequency and a predetermined frequency between the frequency f5 and the frequency f6 as a lower limit frequency.
- the bandpass filter 32-6 has a pass band having a frequency higher than the frequency f6, for example, a lower limit frequency of the bandpass filter 30-5 as an upper limit frequency and a frequency lower than the frequency f6 as a lower limit frequency.
- the output signal of the adder 30-7 is supplied to extraction means, for example, a low-pass filter 32-7.
- the low pass filter 32-7 has a pass band whose cutoff frequency is a frequency higher than the frequency f7, for example, a lower limit frequency of the band pass filter 32-6.
- the output signals of the adders 30-1 to 30-7 that have passed through the high pass filter 32-1, the band pass filters 32-2 to 32-6, and the low pass filter 32-7 are recombined by an adder 34, for example. Recombined, for example added.
- the frequency characteristic of the output signal of the adder 34 is shown in FIG. As apparent from FIG. 8, the output signal of the adder 34 has a wide frequency band. In addition, as described above, it has sharp directivity at the frequencies f1 to f7.
- the output signal of the adder 34 that is, the output signal of the beam forming unit 26 is power amplified by an amplifying means, for example, a power amplifier 36, and supplied to a loudspeaker means, for example, a speaker 38.
- an amplifying means for example, a power amplifier 36
- a loudspeaker means for example, a speaker 38.
- variable delay circuits 24-1 to 24-8 are ignored. That is, the speaker is far away from the first to eighth microphones 14-1 to 14-8 so that the distance difference from the speaker to the first to eighth microphones 14-1 to 14-8 can be ignored. It is assumed that the speaker is making a speech. However, in practice, as shown in FIG. 2, the microphone device 2 is generally installed on the top 6 of the podium 4, and the speaker generally makes a speech in the vicinity of the podium 4. Therefore, distance differences occur between the speaker and the first to eighth microphones 14-1 to 14-8, respectively, and the same sound is transmitted to the first to eighth microphones 14-1 to 14-8. There is a time difference to reach. For this reason, the sound quality of the re-synthesized signal output from the beamforming unit 26 may be different from the original sound quality.
- the audio signals of the first to eighth microphones 14-1 to 14-8 are supplied to the variable delay circuits 24-1 to 24-8, respectively, The same delay as that of the microphone that the signal has reached is given to the audio signal from the other microphone and supplied to the beam forming unit 26. That is, the sound signals of the first to eighth microphones are all supplied to the beam forming unit 26 in the same phase.
- the combined directivity of the first to eighth microphones 14-1 to 14-8 is considered based on the principle of the phased array antenna, the direction of the combined directivity is directed to the speaker.
- the position of the speaker is estimated in order to determine the delay amount in each of the variable delay circuits 24-1 to 24-8, and to set the determined delay amount in each of the variable delay circuits 24-1 to 24-8. Then, it is necessary to determine the distance from the estimated position to the first to eighth microphones 14-1 to 14-8.
- the speaker may move during the speech, or the face may be swung from the center of the stage where the podium is placed to the top or bottom of the stage during the speech. In such a case, each distance between the speaker and the first to eighth microphones 14-1 to 14-8 changes. When the distance changes in this way, it is necessary to change the delay amount of each of the variable delay circuits 24-1 to 24-8 according to the new distance.
- delay amount setting means for example, a speaker position estimation unit 40 is provided.
- a speaker position estimation unit 40 is provided.
- third, seventh and eighth microphones 14-3, 14-7 and 14-8 are supplied to the speaker position estimating unit 40. Since the speaker position estimation unit 40 is the same as the sound source position estimation unit disclosed in Japanese Patent Publication No. 2013-93807, a detailed description of its configuration and operation is omitted.
- variable delay circuits 24-1 to 24-8, the speaker position estimating unit 40, and the beam forming unit 26 are configured on, for example, a rectangular substrate 42 as shown in FIGS.
- the substrate 42 is disposed on the bottom wall 12 so as to be located behind the first to eighth microphones 14-1 to 14-8.
- the substrate 42 is disposed on the bottom wall 12 so as to be inclined obliquely upward in the opposite direction to the first to eighth microphones 14-1 to 14-8. That is, as shown in FIG. 3, one long side of the substrate 42 is located on the bottom wall 12, and the other long side is the back wall of the housing 8 located on the side opposite to the first to eighth microphones. It is located in contact with the upper portion of 44 and forms an acute angle with respect to the bottom wall 12.
- the reason why the substrate 42 is arranged in this way is as follows. If the main surface of the substrate 42 is in contact with the bottom wall 12, that is, if it is horizontally arranged, as described above, the speaker's head is above the top plate 6, so that the speaker's voice is obliquely upward. The sound is directed to the first to eighth microphones 14-1 to 14-8. At this time, the sound is reflected on the horizontally arranged substrate, and the reflected sounds are the first to eighth microphones 14-1 to 14-14. May head -8. As described above, since the through holes 22 formed in the end face of the case 16 of the microphones 14-1 to 14-8 are formed, the reflected sound enters the case 16 from these through holes 22, Sound may be collected by the microphone element 20. In this case, the unidirectionality of the first to eighth microphones 14-1 to 14-8 is impaired.
- the substrate 42 is inclined so as to face the back wall 44 as shown in FIG.
- the sound reflected by the inclined substrate 42 does not go to the first to eighth microphones 14-1 to 14-8 side as indicated by the arrow b in FIG. Therefore, the unidirectionality of the first to eighth microphones 14-1 to 14-8 can be maintained.
- both side walls 46 of the housing 8 that is, the surfaces on the first to eighth microphones 14-1 and 14-8 side, are also separated from the bottom wall 12. It is inclined so as to form an acute angle with respect to the bottom wall 12 so as to face obliquely upward to the outside of the body 8. As a result, the sound that comes from obliquely upward toward the inner surface 46a of the side wall 46 and is reflected by the inner surface 46a is unlikely to move toward the first to eighth microphones 14-1 to 14-8, as indicated by the arrow c. it can.
- the first to eighth microphones 14-1 to 14-8 are arranged directly on the bottom wall 12. However, the first to eighth microphones are separately arranged on the upper surface of the bottom wall 12. Eight microphones can be installed. In the above embodiment, a total of eight microphones of the first to eighth microphones 14-1 to 14-8 are used. However, the number of microphones can be increased or decreased, and three or more microphone units can be configured. Any number of microphones can be used as long as the number is at least five, for example, five or more. In the above embodiment, the eighth microphone 14-1 is provided. However, for example, when it is desired to further reduce the size of the microphone array, the eighth microphone 14-8 can be omitted.
- the variable delay circuit 24-1 to 24-8, the beam forming unit 26, and the speaker position estimating unit 40 are configured by analog processing circuits, and digitize analog audio signals of the first to eighth microphones 14-1 to 14-8. It is also possible. In that case, the variable delay circuits 24-1 to 24-8, the beamforming unit 26, and the speaker position estimating unit 40 are configured by digital circuits. In addition, the variable delay circuits 24-1 to 24-8 can be removed depending on circumstances. In that case, the speaker position estimation unit 40 is also removed.
Abstract
Description
Claims (5)
- n(nは3以上の整数)組のマイクロホンユニットからなり、1組目のマイクロホンユニットは、3本のマイクロユニットを等間隔に一列に配置してなり、m(1<m<nの正の整数)組目のマイクロホンユニットは、m-1番目のマイクロホンユニットの両端のマイクロホンを含み、m-1番目のマイクロホンユニットの両端のマイクロホン間の距離にほぼ等しい距離だけ隔てて、m-1番目のマイクロホンユニットの一方の端のマイクロホンから、一方の端のマイクロホンを挟んで他方の端のマイクロホンとは反対側に位置するマイクロホンを含み、m+1番目のマイクロホンユニットは、m番目のマイクロホンユニットの両端のマイクロホンを含み、m番目のマイクロホンユニットの両端のマイクロホン間の距離にほぼ等しい距離だけ隔てて、m番目のマイクロホンユニットの他方の端のマイクロホンから、他方の端のマイクロホンを挟んで一方の端のマイクロホンとは反対側に位置するマイクロホンを含むマイクロホンアレイと、
前記各マイクロホンユニットのマイクロホンが収集して発生した音声信号を合成して合成信号を出力させる合成手段と、
これら合成手段から出力された合成信号を再合成する再合成手段とを、
具備するマイクロホン装置。 - 請求項1記載のマイクロホン装置において、n+1番目のマイクロホンユニットを構成するために、前記各マイクロホンのうちn番目のマイクロホンユニットのマイクロホン以外のマイクロホンであって、n番目のマイクロホンユニットの両端のマイクロホンのいずれかまでの距離が、n番目のマイクロホンユニットのマイクロホン間の距離よりも長いマイクロホンをn+1番目のマイクロホンユニットの中央のマイクロホンとし、n番目のマイクロホンユニットの両端のマイクロホンのうち前記n+1番目のマイクロホンユニットの中央のマイクロホンへの距離がn番目のマイクロホンユニットのマイクロホン間の距離よりも長いマイクロホンを、n+1番目のマイクロホンユニットの端のマイクロホンとし、n+1番目のマイクロホンユニットの中央のマイクロホンを挟んで、n+1番目のマイクロホンユニットの端のマイクロホンと反対側に、n+1番目のマイクロホンユニットの中央及び端のマイクロホン間の距離にほぼ等しい距離だけ隔てた位置にn+1番目のマイクロホンユニットの別の端のマイクロホンを配置し、n+1番目のマイクロホンユニットのマイクロホンが収集して発生した音声信号を、新たな合成手段で合成し、前記再合成手段に供給するマイクロホン装置。
- 請求項1記載のマイクロホン装置において、前記各マイクロホンは、ケースの内部にマイクロホンエレメントを有し、このエレメントがマイクロホン設置部上にほぼ接するように前記ケースがマイクロホン設置部に埋め込まれているマイクロホン装置。
- 請求項1記載のマイクロホン装置において、前記各合成手段及び再合成手段が設けられた基板が、前記マイクロホンアレイに対して傾斜しているマイクロホン装置。
- 請求項1記載のマイクロホン装置において、前記マイクロホンアレイは筐体内に配置され、前記マイクロホンアレイの両端の両外側に前記筐体の壁が位置し、これら壁が前記マイクロホンアレイに対して傾斜しているマイクロホン装置。
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JP2015522294A JP6132910B2 (ja) | 2013-06-11 | 2013-06-11 | マイクロホン装置 |
PCT/JP2013/066105 WO2014199446A1 (ja) | 2013-06-11 | 2013-06-11 | マイクロホン装置 |
US14/897,147 US9826307B2 (en) | 2013-06-11 | 2013-06-11 | Microphone array including at least three microphone units |
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US9554207B2 (en) | 2015-04-30 | 2017-01-24 | Shure Acquisition Holdings, Inc. | Offset cartridge microphones |
US9565493B2 (en) | 2015-04-30 | 2017-02-07 | Shure Acquisition Holdings, Inc. | Array microphone system and method of assembling the same |
US10367948B2 (en) | 2017-01-13 | 2019-07-30 | Shure Acquisition Holdings, Inc. | Post-mixing acoustic echo cancellation systems and methods |
EP3804356A1 (en) | 2018-06-01 | 2021-04-14 | Shure Acquisition Holdings, Inc. | Pattern-forming microphone array |
US11297423B2 (en) | 2018-06-15 | 2022-04-05 | Shure Acquisition Holdings, Inc. | Endfire linear array microphone |
EP3854108A1 (en) | 2018-09-20 | 2021-07-28 | Shure Acquisition Holdings, Inc. | Adjustable lobe shape for array microphones |
JP2022526761A (ja) | 2019-03-21 | 2022-05-26 | シュアー アクイジッション ホールディングス インコーポレイテッド | 阻止機能を伴うビーム形成マイクロフォンローブの自動集束、領域内自動集束、および自動配置 |
CN113841419A (zh) | 2019-03-21 | 2021-12-24 | 舒尔获得控股公司 | 天花板阵列麦克风的外壳及相关联设计特征 |
US11558693B2 (en) | 2019-03-21 | 2023-01-17 | Shure Acquisition Holdings, Inc. | Auto focus, auto focus within regions, and auto placement of beamformed microphone lobes with inhibition and voice activity detection functionality |
CN114051738A (zh) | 2019-05-23 | 2022-02-15 | 舒尔获得控股公司 | 可操纵扬声器阵列、系统及其方法 |
CN114051637A (zh) | 2019-05-31 | 2022-02-15 | 舒尔获得控股公司 | 集成语音及噪声活动检测的低延时自动混波器 |
JP2022545113A (ja) | 2019-08-23 | 2022-10-25 | シュアー アクイジッション ホールディングス インコーポレイテッド | 指向性が改善された一次元アレイマイクロホン |
US11552611B2 (en) | 2020-02-07 | 2023-01-10 | Shure Acquisition Holdings, Inc. | System and method for automatic adjustment of reference gain |
USD944776S1 (en) | 2020-05-05 | 2022-03-01 | Shure Acquisition Holdings, Inc. | Audio device |
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US20170164106A9 (en) | 2017-06-08 |
US9826307B2 (en) | 2017-11-21 |
US20160150316A1 (en) | 2016-05-26 |
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