EP3788796A1 - Mikrofonarray - Google Patents
MikrofonarrayInfo
- Publication number
- EP3788796A1 EP3788796A1 EP19725653.0A EP19725653A EP3788796A1 EP 3788796 A1 EP3788796 A1 EP 3788796A1 EP 19725653 A EP19725653 A EP 19725653A EP 3788796 A1 EP3788796 A1 EP 3788796A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- microphones
- microphone array
- microphone
- high sensitivity
- circle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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Classifications
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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
- 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
- H04R1/326—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only for 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
- 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
-
- 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
- H04R2201/401—2D or 3D arrays of transducers
-
- 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
-
- 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 invention relates to a microphone array.
- the acoustic events on the playing field may be particularly interesting for immersive playback, such as the sounds of the ball, the bat, etc., and the conversations of the players, referees, coaches, etc.
- the noise mainly comprises the noise of the audience, which is usually located in the sports venues on bleachers.
- the microphones for sound recording should not obstruct the view neither the audience nor the cameras usually available.
- a typical example is the playing field of a football stadium, where ball sounds, player calls, the referee's whistle and coaching instructions are to be recorded. Comparable problems can occur in other sports such as baseball or in other situations in which sound recordings are to be made of sound sources that are distributed over a flat surface and possibly movable and despite noise from the environment not directly provided with a microphone can be.
- a solution known as "KICK" by LAWO consists of a set-up of numerous directional microphones or microphones with a super-cardioid characteristic distributed around a soccer field at the edge of the field parallel to the ground (https://www.lawo.com/en/products /audio-production-tools/kick.html).
- the position data is input to an automatic audio mixing unit which also receives the output signals of the microphones and processes and weights and mixes them according to the position data.
- the underlying idea is that signals from microphones that are closest to the current ball position are weighted very highly.
- a disadvantage of this known solution is that a high cabling effort is required.
- the cables and microphones must be routed before each game and dismantled after each game. Additional microphones require additional cables and make the system more expensive.
- the fixed orientation of the microphones ensures that their optimally detected area must be relatively wide to cover also areas between adjacent microphones. Nevertheless, these areas are recorded only with low sound quality and thus suboptimal.
- a larger detection area of the microphones in the plane azimuth angle
- the vertical detection area elevation angle
- Another possible solution consists in manual alignment or tracking of directional microphones with a particularly high directivity. However, this is associated with a time delay. In addition, in the case of manual alignment operator for each directional microphone is necessary, and it can transmit structure-borne noise to the microphone. A possible remote control for tracking the microphones would both additional delays and engine noise occur that would inevitably recorded by the microphone and audible as noise. A misalignment of a directional microphone affects different frequencies differently, because the directivity of the directional microphones is higher for higher frequencies than for lower ones. This causes the tone of the sound signal to change constantly. Another known solution for achieving high directivity is beamforming. The output signals of several, arranged in an array microphones are interconnected, for example by means of delay, addition and filtering.
- the resulting beam ie the region of particularly high sensitivity, has an adjustable direction and is usually rotationally symmetrical.
- the particular shape of the beam depends on the type, number and arrangement of the microphones as well as the algorithm used for the combination.
- Typical algorithms include the delay and summation algorithm ("delay-and-sum", DS) and the “minimum variance distortionless response” (MVDR) algorithm, which however also have disadvantages.
- DS delay-and-sum
- MVDR minimum variance distortionless response
- microphone arrays are constructed from microphones with little or no directivity because they are easy to handle and inexpensive. In order to obtain a high directivity over a wide azimuth angle and a comparable directivity with respect to the elevation, very many microphones are necessary, which leads to a high computational effort. It is therefore an object of the present invention to provide a microphone arrangement which solves the above problems.
- an array of circular shotgun microphones is known (Y. Sasaki, T. Nishiguchi, K. Ono: “Development of multichannel single-unit microphone using shotgun microphone array”).
- adjacent shotgun microphones are used to narrow the rotationally symmetrical directional characteristic of each individual shotgun microphone at low frequencies by filtering in addition to the respective direction.
- shotgun microphones are considered an alternative Beamforming used.
- An object of the present invention is to provide a microphone assembly with a particularly high directivity in the vertical direction and a high, but adjustable within wide limits directivity in the horizontal direction.
- the object is achieved by the microphone array specified in claim 1.
- a microphone array has a plurality of microphones whose output signals are combined to form at least one common output signal, wherein the microphones are shotgun microphones with a preferred direction of high sensitivity is arranged.
- the microphones are also essentially uniform on a circle or circular portion such that each of the microphones has another preferred direction of high sensitivity, and preferably the angles between the individual microphones are substantially equal over the entire circle or circle segment.
- the microphones can point inwards or outwards with respect to the circle or circle section. In one embodiment, all microphones lie substantially in one plane. In another embodiment, the microphones are in several, z. B. two or three, parallel and adjacent levels. The thickness of each level can correspond approximately to the diameter of a microphone or shotgun.
- the common output of the microphone array is obtained by beamforming. Due to the high directivity of the shotgun microphones, both the elevation angle and the azimuth angle of the detection range of the arrangement are very small, while the azimuth angle in a very large range, which can be up to 360 °, is adjustable. The resulting directivity of the microphone array in the azimuth direction can be stronger than the directivity of a single shotgun microphone, even if none of the shotgun microphones points in the appropriate direction. In embodiments in which the microphones are distributed over a full circle, always show some shotgun microphones against the actual target direction. This allows a consistent directional characteristic regardless of the orientation of the microphone array.
- a method for audio recording by means of shotgun microphones is specified in claim 12.
- FIG. 1 shows a microphone array in a first embodiment
- FIG. 2 shows a shotgun microphone with interference tube
- FIG. 3 shows a block diagram of a signal processing for the beamforming algorithm
- FIG. 5 shows a microphone array in a third embodiment
- FIG. 6 shows a microphone array in a fourth embodiment
- FIG. 7 shows a block diagram of a multi-focus signal processing for the beamforming algorithm
- 8 shows a diagram of the radial components of modal responses of a Sennheiser MKH8070 shotgun microphone
- FIG. 10 is a perspective view of a microphone array in an embodiment.
- each of the directional microphones 110 contains a microphone capsule, wherein the microphone capsules of all directional microphones 110 are arranged on a circle 120 with the radius r about a center point C around.
- each directional microphone 110 includes an interference tube orthogonal to the circle 120 and directed radially outward. The interference tube provides the directional characteristic of the respective directional microphone.
- the microphones are therefore also referred to as shotgun microphones. The preferred direction of high sensitivity of each
- Shotgun microphone is in its respective longitudinal direction, ie also orthogonal to the circle 120 and radially to the entire arrangement.
- each microphone has another preferred direction of high sensitivity.
- all shotgun microphones can be arranged substantially in a common plane. The entire arrangement is e.g. positioned in a football stadium substantially horizontally, so that the shotgun microphones are aligned parallel to the ground.
- the shotgun microphones could be arranged in two or more different planes. These levels should preferably be close together.
- the microphones can basically also be arranged in completely different levels, but then the sensitivity of all microphones with respect to a defined elevation should be similar. In other words, the "viewing directions" or focus areas of the various microphones should all be substantially in one plane at an intended distance.
- the radius of circle 120 or circular segment determines the alias frequency and the operating frequency range. A larger radius with a constant number of directional microphones results in enhancements for low frequencies, leading to a shift of this range to lower frequencies and to a lower alias frequency. Increasing the number of microphones results in a higher alias frequency.
- the shotgun microphone 200 includes a tube 210 acting as an interference tube with a microphone capsule 240 (not visible in the drawing) therein.
- the microphone capsule can be electrically connected via an electrical connection 250 at the rear end of the shotgun microphone.
- the aiming tube 210 includes in this example at its front end one or more openings 230, which serve the sound inlet. Laterally distributed over the length of the tube are further openings 220, through which sound arriving laterally can also enter the tube. This incident sound also passes through the openings 230 in the tube, but out of phase because of the longer path. In the tube, it overlaps with the incident through the side openings 220 lateral sound.
- the side openings 220 of the interference tube are normally not distributed over its circumference, but are located on only one side, which is referred to below as the top of the shotgun microphone.
- Shotgun microphones offer the advantage of a particularly high directivity, which refers both to a very small azimuth angle and a very small elevation angle.
- the elevation angle is the angle perpendicular to the plane of the drawing in FIG. 1.
- the azimuth angle, ie the angle in the drawing plane of FIG. 1 of each shotgun microphone is very small, but by including adjacent shotgun microphones and by suitable calculations for combining the different microphone signals can be a directivity of the entire arrangement in the plane control.
- the directivity of a rotationally symmetrical arrangement as in FIG. 1 can be controlled electronically in any direction of the plane, ie at any arbitrary azimuth angle.
- the elevation angle of the directional characteristic of the entire arrangement is the same as the elevation angle of the directional characteristic of each directional tube microphone, so very small. Therefore, it is not necessary to arrange microphones in multiple vertical planes to achieve high vertical directivity. This results in a flat arrangement that does not disturb the view of the audience or cameras in a sports stadium, for example, when the microphone array is positioned at the edge of the field. In addition, no calculations are required for a (possibly time-variable) combination of the microphone signals via the vertical axis.
- a further advantage of a rotationally symmetrical arrangement as in FIG. 1 is that the directivity as well as the frequency characteristic is uniform in any direction of the plane, ie at any arbitrary azimuth angle.
- One possible and particularly advantageous signal processing for the microphone array is the beamforming algorithm.
- the beamforming is based on the so-called modal beamforming, which is especially suitable for configurations in which all microphones have essentially the same directivity (directivity) and are arranged on a sphere or on a circle.
- directivity directivity
- the number Q of the used microphones determines the maximum realizable degree M of the output signal, which corresponds to the spatial resolution of the radiation pattern (beam pattem), according to M
- the processing is done in two steps: (a) frequency-independent mixing (or matrixing) of the microphone signals to produce 2M + 1 intermediate or mixed signals, and (b) filtering and then weighting and summing the intermediate or mixed signals.
- the control ie the indication of information about the desired azimuth angle Ft
- the control can be achieved either manually or automatically, eg by a visual tracking system.
- the filtered signals are weighted prior to summing, which facilitates the simultaneous recording of multiple sound sources as targets. An example is shown in Fig. 7 and will be explained below.
- FIG. 3 shows a block diagram of a signal processing for the modal beamforming algorithm for an array of circularly arranged directional microphones.
- the Q microphone signals C (w, ci C (w, co) are mixed independently of frequency in a transformation matrix ⁇ (f 1 , f 2 , ..., Fo) 310.
- the transformation matrix applies to a desired maximum degree and provides (2M + 1) output signals.
- Each output signal is filtered, whereby of the (2M + 1) filters 320, ..., 322 ', one filter 320 occurs once and all others twice as a filter pair 321, 32T.
- the filter 321 for the (-M + 1) th output of the matrix and the filter 32T for the (M-1) th output of the matrix are equal.
- Each filter or filter pair has its own filter function, according to an order of a specific mode.
- the output of each filter 32Q, ..., 322 ' is output in one or more weighting units 330 corresponding to the desired azimuth direction Ft with a corresponding value (gain). g ⁇ weighted.
- the 2M + 1 weighted filtered composite signals are summed in a summation unit 340, and the sum signal U (w) can then either be output as output 360, or optionally filtered in an equalization filter 350 and then output.
- a very flexible time-varying beamforming is possible.
- the number of directional microphones determines the spatial resolution of the possible directional characteristic, in particular the maximum directivity index, which indicates the ratio between the output power with respect to a desired target direction and the total output power integrated over all other directions.
- the circular harmonic transform described below it is advantageous to use a uniform distribution of the microphones on a circle in view of the assumption made therefor. This ensures consistent signal quality over all (azimuth) directions, as intended in modal beamforming.
- FIG. 5 shows a microphone array 500 in a third embodiment, in which each of the eleven directional microphones 510i,..., 510n is rotated by an angle a and their microphone capsules are arranged on a circle 520.
- the algorithm used must take this rotation into account, with very small angles being negligible.
- FIG. 6 shows a microphone array 600 in a fourth embodiment, in which eleven directional microphones 610i,..., 610n are again distributed uniformly over a semicircle 620. For a central alignment near 0 ° corresponding to the microphone 610e, this arrangement is easily replaceable.
- a microphone array of the shape shown in Fig. 6 is e.g. replaceable at the corners of a playing field where a range of substantially 90 ° is to be detected.
- Fig. 7 shows a block diagram of a multi-focus signal processing for the beamforming algorithm.
- the multi-focus signal processing includes a mixing matrix 310 for mixing the microphone signals to (2M + 1) mixed signals, where M is the order of the common output, and a plurality of (2M + 1) filters 320,321, 321 ', 322,322 * for filtering the mixed signals, resulting in filtered mixed signals QF-M, QF-M + I, ..., QFO, ..., QFM-I, QFM.
- the filtered ones Mixed signals are now forwarded not only to (2M + 1) first weighting units 330i, but also to (2M + 1) second weighting units 3302.
- the first weighting units 330i weight each of the filtered composite signals with a first weighting gM ( ®Ti ) ,. .., go ⁇ ®Ti ) ,. .., gM i ®Ti ) , and the second weighting units 3302 weight each of the filtered composite signals with a second weight gM ( ®T2 ) ,.
- each first weighting unit corresponds to the first preferred high sensitivity direction Fti
- the weighting of every other weighting unit corresponds to the second preferred high sensitivity direction
- FTS first weighting units 330i and the output signals of the second weighting units 3302 are separately added in two separate summation units 340I, 3402, optionally filtered 350I, 3502, and then outputted.Thus, the microphone array simultaneously has two preferred high sensitivity directions Fti, Ft2.
- the second weighting units 330 2 are the same process filtered mixed signals as the first weighting units 330i and use only another directional information for the preferred high sensitivity direction Ft2. Therefore, the filters 320, ..., 322 'need only be calculated and implemented once, because they are direction independent.
- the weighting units can be implemented as multipliers, for example.
- the entire arrangement shown in FIG. 3 or in FIG. 7 can be realized by one or more microprocessors, if necessary with corresponding software programs.
- ro is the radius of the circle and the azimuth glows of the qth microphone measured counterclockwise in the xy plane from the x axis.
- the representation of the q-th microphone signal in the frequency domain at an angular frequency w can be described as a superposition (composition) of responses to individual plane waves that arrive from all possible azimuth angles F, ie
- H (w, F) is the so-called plane wave amplitude density function, which is essentially a frequency domain representation of the sound pressure at the origin originated by a single plane wave incident at an azimuth angle F.
- H (w, xq , f) is the directional characteristic of the qth microphone.
- the individual weights H h (w, x q ) of the circular harmonic series in (4) are referred to as modal responses of degree m.
- the modal responses can be factored into a frequency- and radius-dependent component and another component that depends only on the azimuth angle according to
- FIGS. 3 and 7 A block diagram of a typical modal beamformer is shown in FIGS. 3 and 7 as described above. The two steps mentioned below are described in more detail below.
- the maximum absolute value of the degree m that can be reconstructed is also finite and depends on the distribution of the spatial sampling points x q on the circle.
- the weights are all the same for the particular case of uniform distribution, viz and the maximum absolute value of the degree m that can be reconstructed is given by
- this matrix is frequency independent.
- the individual plane waves of the acting sound field are now weighted in accordance with a desired directional characteristic in order to be subsequently integrated or summed up.
- the maximum degree M of the circular harmonic series coefficients of the amplitude density function of the plane wave determines the maximum possible spatial resolution of the desired directional characteristic. Therefore, a prototype of a desired directional characteristic is defined by means of a broken circular harmonic series expansion of the same degree M:
- the current beamformer output signal 7 (w) in the frequency domain is calculated as the weighted sum of the circular harmonic series coefficients of the amplitude density function of the plane wave as follows:
- the frequency-independent directional characteristic used here is advantageous and desirable.
- an equalizing filter 350, 350 ' may be applied to the output signal 7 (w) of the beamformer to produce a directional coloration or to compensate for directional staining, e.g. to attenuate high-frequency signal components affected by spatial aliasing.
- the radius of the circle on which the microphone capsules of the directional microphones are arranged influences at least two characteristic values of the array, namely the directivity which can be achieved in practice at low frequencies and the frequency at which spatial aliasing sets in.
- the directivity at low frequencies is affected as follows.
- the radial components & m (c ⁇ j , r 0 ) of the modal responses typically have a high-pass characteristic, with the cutoff frequency increasing with the degree index m.
- FIG. 8 shows by way of example a diagram of the radial components of modal responses for different degrees m of a Sennheiser MKH8070 shotgun microphone, plotted over a product 0 .
- the contributions of the modes with increasing degree m within the measured microphone signals (16) very small. Therefore, in order to reconstruct the corresponding circular harmonic series coefficients of the amplitude density function of the plane wave, a high gain of -j- - is necessary (see (26))
- Spatial aliasing is a phenomenon that occurs when, for example, a sound field is scanned at too few sample points in order to detect high-frequency spatial oscillations of the sound pressure. Since the relevance of higher-order circular harmonics within the signature function normally increases with the spectral frequency, so does the size of the spatial aliasing error. In particular, the angular frequency at which the contribution of the circular harmonics with degrees greater than M to the signature function becomes significant can be regarded as the frequency at which the aliasing effect becomes disturbing or noteworthy. Essentially, this angular frequency is included
- the spatial aliasing frequency can be increased by reducing the radius r of the array.
- the number of microphones can be increased.
- FIG. 9 schematically shows a microphone array 900 with eleven shotgated microphones in a fifth embodiment, in which the individual shotgun microphones 910i,..., 91011 are oriented substantially in the direction of the center C of the array.
- the respective microphone capsules lie on the circle 920 of radius r.
- FIG. 10 shows in a further embodiment a perspective view of a similar microphone array 1000 with fifteen shotgun microphones 1010i,..., 1010i5, which are likewise aligned in the direction of the center C of the array.
- the microphones can e.g. to be mounted on a ring or plate.
- the side openings 220 of the interference tubes of the shotgun microphones 1010i, ..., 1010i5 must not be obscured, since they represent the most important inlet openings for the sound here.
- the shotgun microphones 1010i, ..1010is are not replaced by the opposite ones, i. disturbed in the "direction of view" shotgun microphones.
- the shotgun microphones 1010i, ..., 1010i5 are therefore arranged so that their tops with the side openings 220 are freely accessible to the sound and preferably all point in the same direction.
- the shotgun microphones 1010i,..., 1010i5 lie essentially in one plane, wherein the directivity of the microphone array can be controlled electronically within this plane. It should be noted that the illustration in Fig. 10 is not necessarily to scale. For example, the microphones 1010i, ..., 101 Ois should be distributed as evenly as possible over the circle 1020.
- a particular advantage of the microphone array according to the invention is that it does not have to be moved, but remains stationary, whereby the direction of highest sensitivity can be adjusted by electronic control, in the case of the circular arrangement in any direction within the circle plane (corresponding to an azimuth). Mutual angle of 0 ° -360 ° with horizontal structure). It may be useful in other applications to position the circle plane vertically to detect an elevation angle of 0 ° -360 ° while keeping the azimuth angle of the detection area very low. Likewise, any intermediate orientations of the microphone level are possible. As shown in the drawings, there is no microphone in the center of the assembly.
- the specified number of directional microphones per array is the respective Minimum number; it is always possible and may be advantageous to increase the number Q of microphones, as explained above. The number Q can be even or odd.
- the invention relates to a method of audio recording by means of a microphone array of directional microphones, wherein at least one common output signal is generated containing the sound in an adjustable preferred direction of high sensitivity of the microphone array, comprising the steps of: mixing a plurality of microphone signals in a mixing matrix on (2M + 1) mixed signals, where M is the order of the common output signal, and wherein the microphone signals come from the directional microphones and the directional microphones are arranged substantially in one plane and on a circle or circle section such that a preferred one for each of the directional microphones Direction of high sensitivity is substantially orthogonal outward or inward of the circle or circular section, filtering the mixed signals in a plurality of (2M + 1) filters, resulting in filtered mixed signals, weighting each of the filtered mixed signals with a weighting in a plurality of (2M + 1) weighting units, wherein the weighting of each weighting unit corresponds to the adjustable preferred direction of high sensitivity of the microphone array, and summing up the (2M + 1) weighte
- the embodiments described above are exemplary and can be combined with each other, even if such a combination is not explicitly mentioned.
- the individual directional microphones can also point inwards in an array arrangement as shown in FIG. 5, as in FIGS. 9 and 10.
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- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- General Health & Medical Sciences (AREA)
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Abstract
Description
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Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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DE102018110759.5A DE102018110759A1 (de) | 2018-05-04 | 2018-05-04 | Mikrofonarray |
PCT/EP2019/061529 WO2019211487A1 (de) | 2018-05-04 | 2019-05-06 | Mikrofonarray |
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EP3788796A1 true EP3788796A1 (de) | 2021-03-10 |
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Family Applications (1)
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EP19725653.0A Pending EP3788796A1 (de) | 2018-05-04 | 2019-05-06 | Mikrofonarray |
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US (1) | US11418871B2 (de) |
EP (1) | EP3788796A1 (de) |
DE (1) | DE102018110759A1 (de) |
WO (1) | WO2019211487A1 (de) |
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DE102019134541A1 (de) | 2019-12-16 | 2021-06-17 | Sennheiser Electronic Gmbh & Co. Kg | Verfahren zur Steuerung eines Mikrofonarrays und Vorrichtung zur Steuerung eines Mikrofonarrays |
TWI818590B (zh) * | 2022-06-16 | 2023-10-11 | 趙平 | 全向收音裝置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2760177B2 (ja) * | 1991-09-10 | 1998-05-28 | 松下電器産業株式会社 | 音源位置推定方法 |
EP1538867B1 (de) * | 2003-06-30 | 2012-07-18 | Nuance Communications, Inc. | Freisprechanlage für ein Kraftfahrzeug |
US7415117B2 (en) * | 2004-03-02 | 2008-08-19 | Microsoft Corporation | System and method for beamforming using a microphone array |
US9190069B2 (en) * | 2005-11-22 | 2015-11-17 | 2236008 Ontario Inc. | In-situ voice reinforcement system |
EP2168396B1 (de) * | 2007-07-09 | 2019-01-16 | MH Acoustics, LLC | Vergrösserte elliptische mikrofonanordnung |
US8861756B2 (en) * | 2010-09-24 | 2014-10-14 | LI Creative Technologies, Inc. | Microphone array system |
US20130315404A1 (en) * | 2012-05-25 | 2013-11-28 | Bruce Goldfeder | Optimum broadcast audio capturing apparatus, method and system |
EP2738762A1 (de) * | 2012-11-30 | 2014-06-04 | Aalto-Korkeakoulusäätiö | Verfahren zur Raumfilterung von mindestens einem ersten Tonsignal, computerlesbares Speichermedium und Raumfilterungssystem basierend auf Kreuzmuster-Kohärenz |
WO2015013058A1 (en) * | 2013-07-24 | 2015-01-29 | Mh Acoustics, Llc | Adaptive beamforming for eigenbeamforming microphone arrays |
US10026399B2 (en) | 2015-09-11 | 2018-07-17 | Amazon Technologies, Inc. | Arbitration between voice-enabled devices |
EP3188504B1 (de) * | 2016-01-04 | 2020-07-29 | Harman Becker Automotive Systems GmbH | Multimedia-wiedergabe für eine vielzahl von empfängern |
US10510362B2 (en) * | 2017-03-31 | 2019-12-17 | Bose Corporation | Directional capture of audio based on voice-activity detection |
-
2018
- 2018-05-04 DE DE102018110759.5A patent/DE102018110759A1/de active Pending
-
2019
- 2019-05-06 US US17/051,242 patent/US11418871B2/en active Active
- 2019-05-06 WO PCT/EP2019/061529 patent/WO2019211487A1/de active Application Filing
- 2019-05-06 EP EP19725653.0A patent/EP3788796A1/de active Pending
Also Published As
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US11418871B2 (en) | 2022-08-16 |
US20210235187A1 (en) | 2021-07-29 |
DE102018110759A1 (de) | 2019-11-07 |
WO2019211487A1 (de) | 2019-11-07 |
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