Multi-dimensional array microphone

Abstract

Embodiments include an array microphone comprising: a plurality of microphone plates arranged in a linear pattern along a first axis and comprising a plurality of microphone elements configured to cover a plurality of frequency bands, each microphone plate comprising: a first linear array and a second linear array, the first linear array includes a first microphone element of the plurality of microphone elements and one or more second microphone elements of the plurality of microphone elements, the first microphone element being located on the first axis, the one or more second microphone elements being located on the second axis. And the one or more second microphone elements are located on a second axis orthogonal to the first axis, the second linear array comprising the first microphone elements and one or more third microphone elements of the plurality of microphone elements, the one or more third microphone elements are located on a third axis orthogonal to the first axis and the second axis.

Description

[0001] Cross-referencing

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 501,998, filed May 12, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application generally relates to an array microphone. More specifically, this application relates to a multi-dimensional array microphone configured to provide improved frequency-dependent directivity. Background Technology

[0004] Audio environments, such as conference rooms, boardrooms and other meeting rooms, and video conferencing scenarios, may involve using one or more microphones to capture sound from various active audio sources within the environment. For example, audio sources might include a human speaker within the room. The captured sound can be amplified through speakers (for sound reinforcement) to the on-site audience in the environment and / or to others remotely (e.g., via television broadcasts, webcasts, etc.). For instance, people in a conference room might be having a conference call with remote individuals.

[0005] Generally, microphones and other audio acquisition devices (such as conferencing equipment) are available in a variety of sizes, form factors, mounting options, and wiring options to meet the needs of specific environments. Furthermore, microphones can be designed to produce different polarity response patterns, including omnidirectional, cardioid, subcardioid, supercardioid, hypercardioid, and bidirectional. The type of conferencing equipment, its operating characteristics (e.g., lobe direction, gain, polarity pattern, etc.), and its placement in a specific audio environment can depend on many factors, including, for example, the location of the sound source, the location of the audience, the need to eliminate extraneous noise, physical space requirements, aesthetics, room layout, and / or other considerations. For example, in some environments, conferencing equipment may be placed on a table or podium close to the audio source and / or the audience. In other environments, conferencing equipment may be mounted overhead or on a wall, for example, to capture sound from throughout the room or project sound throughout the room.

[0006] Microelectromechanical systems (“MEMS”) microphones, or microphones with MEMS elements as their core transducers, are gaining popularity due to their smaller package size. This allows audio devices to have a smaller, thinner overall form factor (e.g., compared to conventional microphones such as dynamic, crystal, condenser, edge, and push-button microphones); high performance characteristics (e.g., high signal-to-noise ratio (“SNR”), low power consumption, high sensitivity, etc.); low cost (e.g., compared to electret or condenser microphone pickups); and ease of overall assembly. While conventional MEMS microphones inherently possess an omnidirectional polarity pattern (i.e., the microphone is equally sensitive to sound from any and all directions regardless of its orientation), placing MEMS microphones in an array configuration and applying appropriate beamforming techniques (e.g., signal processing) can produce a directional response, or a beam pattern that is more sensitive to sound from one or more specific directions than to sound from other directions. Summary of the Invention

[0007] The technology disclosed herein provides related systems and methods designed for purposes including, but not limited to, the following three points: (1) providing an array microphone with a three-dimensional structure and microphone layout having improved directivity transverse to the array axis; (2) using appropriate beamforming techniques to steerably control the maximum sensitivity direction of the array to point to any point at any azimuth and elevation angle around a sphere surrounding the center of the array, thereby enhancing the ability to guide the array to the most effective sound-collecting location and achieving null generation; and (3) high-performance acoustic characteristics suitable for conference environments, stages, sports and other entertainment environments, including selectively covering the stage or audience and / or isolating ambient noise from game audio, as well as live sound reinforcement.

[0008] For example, one embodiment includes an array microphone comprising a plurality of microphone panels arranged in a linear pattern along a first axis, and a plurality of microphone elements configured to cover multiple frequency bands. Each microphone panel includes: a first linear array and a second linear array. The first linear array includes a first microphone element and one or more second microphone elements, wherein the first microphone element is located on the first axis, and the one or more second microphone elements are located on a second axis orthogonal to the first axis. The second linear array includes the first microphone element and one or more third microphone elements, wherein the one or more third microphone elements are located on a third axis orthogonal to the first and second axes. Depending on various aspects, the linear pattern may be configured to place the microphone panels in a harmonic nesting configuration to cover multiple frequency bands.

[0009] Another exemplary embodiment provides an array microphone including a plurality of microphone boards arranged in a first linear pattern along a first axis of the array microphone. The plurality of microphone boards include a plurality of microphone elements configured to cover a plurality of frequency bands. Each microphone board includes: a first microphone element among a plurality of microphone elements located on the first axis; one or more second microphone elements among a plurality of microphone elements located on a second axis of the microphone board, the second axis being orthogonal to the first axis; and one or more third microphone elements among a plurality of microphone elements located on a third axis of the microphone board, the third axis being orthogonal to the first axis and the second axis. The first microphone elements of the plurality of microphone boards are configured to form a first linear pattern along the first axis, and for each microphone board, the first microphone element and one or more second microphone elements are configured to form a second linear pattern along the second axis of the corresponding microphone board, and the first microphone element and one or more third microphone elements are configured to form a second linear pattern along the third axis of the corresponding microphone board.

[0010] Another exemplary embodiment provides a microphone system comprising: an array microphone including a plurality of microphone elements arranged on a plurality of microphone plates, the array microphone being configured to provide audio coverage for a plurality of frequency bands; and one or more audio processors in communication with the array microphone and including one or more beamformers, the one or more audio processors being configured to use the one or more beamformers to: direct audio pickup lobes of the array microphone to an audio source detected at a first point; and generate an audio output based on an audio signal generated by the audio source and captured using the audio pickup lobes, wherein the one or more beamformers are configured to direct the audio pickup lobes to any one of a plurality of points located on a sphere surrounding the center of the array microphone, the plurality of points including the first point. According to some aspects, the plurality of points are located at different azimuth and elevation angles around the sphere. According to some aspects, the plurality of points cover a solid angle of four times π spherical degrees. According to some aspects, the audio pickup lobes include the highest sensitivity pointing of the array microphone.

[0011] These and other embodiments, as well as various arrangements and aspects, will become apparent and more fully understood from the following detailed description and accompanying drawings, which illustrate exemplary embodiments that may demonstrate various ways in which the principles of the invention can be applied. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of an exemplary array microphone placed horizontally according to one or more embodiments.

[0013] Figure 2 According to one or more embodiments Figure 1A side view of the array microphones.

[0014] Figure 3A According to one or more embodiments Figure 1 A top view of the array microphones.

[0015] Figure 3B According to one or more embodiments Figure 3A A close-up view of the main array contained in the array microphone.

[0016] Figure 4 It is vertically placed according to one or more embodiments. Figure 1 A schematic diagram of an array microphone.

[0017] Figure 5A This is a schematic diagram of an exemplary microphone board placed vertically according to one or more embodiments.

[0018] Figure 5B It is horizontally placed according to one or more embodiments. Figure 5A A schematic diagram of the microphone board.

[0019] Figure 6 This is a schematic diagram of an exemplary microphone board oriented relative to the XYZ axes according to one or more embodiments.

[0020] Figure 7 According to one or more embodiments Figure 1 A schematic diagram of the first plane of the array microphone.

[0021] Figure 8 This is a schematic diagram of the first plane of another exemplary array microphone according to one or more embodiments.

[0022] Figure 9 This is a block diagram of an exemplary audio system including an array microphone according to one or more embodiments.

[0023] Figure 10 According to the embodiments Figure 9 A block diagram of an audio system containing an array microphone and a beamformer.

[0024] Figure 11 According to the embodiments Figure 10 A block diagram of an exemplary sum-difference beamformer included in the beamformer.

[0025] Figure 12 According to the embodiments Figure 10 A block diagram of an exemplary pattern-forming beamformer included in the beamformer. Detailed Implementation

[0026] Typically, array microphones consist of multiple microphone elements aligned in a specific pattern or geometry (e.g., linear, circular, etc.) and configured to operate as a single microphone device. For example, a linear array microphone consists of microphone elements relatively close together along a single axis. Array microphones can have different configurations and frequency responses depending on the relative positions of the microphone elements and the direction of sound wave incidence. The directivity of array microphones can also provide a controllable coverage area, or a pickup pattern that focuses on a desired audio source and suppresses irrelevant sounds (such as room noise), and this controllability can be achieved by picking up multiple audio sources using a single array or device. For example, a lateral linear array consisting of a row of MEMS microphones (with microphones arranged perpendicular to the preferred direction of sound incidence) can use a delay-summing beamformer to combine signals from the individual microphone elements accordingly to achieve the desired pickup pattern. In some lateral arrays, microphone elements are placed in nested pairs around a central point and can be spaced apart by a predetermined distance to cover a variety of frequencies.

[0027] This paper provides a system and method for a multidimensional array microphone that adds directivity to most (if not all) frequencies in all dimensions. Specifically, the array microphone includes a first plurality of microphone elements arranged in a linear pattern along a first axis, a second plurality of differential complementary microphone elements arranged along a second perpendicular axis, and a third plurality of differential complementary microphone elements arranged along a third mutually perpendicular axis. The linear pattern can be configured to place the first plurality of microphone elements in a harmonic nesting configuration to cover multiple frequency bands. The second and third plurality of microphone elements can be configured to form mirror images of each other in the second and third linear patterns, respectively. This geometry provides not only array control perpendicular to the first axis (or the axis of the array microphone) but also control around the array axis, such that the direction of the maximum or highest value of microphone sensitivity can be pointed to any position within a sphere around the center of the array at any azimuth and elevation angle, or to cover a solid angle of four times π spherical degrees using appropriate beamforming techniques. For example, in an embodiment, microphone elements along two or more axes can be combined to generate any first-order pointing pattern (e.g., cardioid, ring, etc.) that can be oriented in any direction around a defined sphere to capture desired sound sources or generate nulls to suppress irrelevant sound sources.

[0028] Furthermore, the multidimensional shape factor of the array microphone is achieved by arranging microphone elements on multiple microphone boards (e.g., made of printed circuit board (PCB) substrates or the like), which are structurally independent but electrically connected together and configured to minimize the influence of the array structure on the incident sound field. For example, in one embodiment, each board is aligned at its center point with a first axis to support a corresponding one of a first plurality of microphones, and each board has a predetermined shape extending outward from that point and is configured to support a second plurality of microphones along a second axis and a third plurality of microphones along a third axis. The multidimensional structure is further configured to minimize the total number of microphone elements used and the number of PCB substrates used, thereby reducing diffraction and geometric shading that may occur in the three-dimensional array, while improving the directivity and flexibility of the array.

[0029] Figures 1 to 3B An exemplary array microphone 100 according to an embodiment is shown for detecting sound from one or more audio sources of different frequencies, such as the voice of a human speaker. The array microphone 100 can be used in meeting environments, such as conference rooms, boardrooms, or other meeting rooms; entertainment environments, such as stages, stadiums, or other live performance venues; or any other environment where the audio source may contain one or more human speakers or talkers. Other undesirable sounds may be present in the environment, such as ambient noise and / or noise from ventilation systems, other people (e.g., audience members, non-participants in a conference call, etc.), audiovisual equipment, electronic devices, etc. In a meeting setting, the audio source may be located on a chair next to a table, but other configurations and placements of the audio source are also conceivable and possible, including, for example, audio sources that move within the room. Similarly, in a live performance setting, the audio source may be located on one or more stages or other performance areas, in a designated location and / or possibly moving around or between stages.

[0030] The array microphone 100 includes multiple microphone elements 102 (also referred to herein as “transducers” and “pickup heads”) capable of forming multiple pickup patterns to detect and capture sound from an audio source in an optimal or consistent manner. The pickup patterns that can be formed by the array microphone 100 may depend on the position of the microphone elements 102 within the array 100 and the type of beamformer used to process the audio signals generated by the microphone elements 102. For example, sum and difference beamformers can be used to form cardioid, subcardioid, supercardioid, hypercardioid, bidirectional, and / or ring polar patterns directed towards the desired sound source. Additional polar patterns can be created by combining original polar patterns, and the combined polar patterns can be directed at arbitrary angles, such as along the table where the array microphone 100 is placed, the wall on which the array microphone 100 is mounted, or other planes perpendicular to the axis of the array microphone 100. In some embodiments, multiple beamforming techniques can be combined to direct the direction of highest sensitivity to any direction at any azimuth and elevation angle on a sphere around the center of the array, or to cover a solid angle of four times π spherical degrees. Other beamforming techniques can also be used to combine the outputs of microphone element 102 to achieve the desired frequency response for the entire array microphone 100, for example, including lower noise characteristics, higher microphone sensitivity, and coverage of discrete frequency bands, as described in more detail herein. References will follow. Figures 10 to 12 The beamforming technology used in the array microphone 100 is described in more detail.

[0031] In a preferred embodiment, each microphone element 102 may be a MEMS (microelectromechanical system) transducer with an inherent omnidirectional polarity pattern. In some embodiments, the microphone element 102 may be any type of omnidirectional microphone. In other embodiments, the microphone element 102 may have other polarity patterns and / or may be a condenser microphone, a dynamic microphone, a piezoelectric microphone, or other types of conventional microphones. In other embodiments, the arrangement and / or processing techniques described herein can be applied to other types of arrays consisting of omnidirectional transducers or sensors that require directional orientation (e.g., sonar arrays, radio frequency applications, seismic devices, etc.). Furthermore, although Figure 1 A specific number of microphone elements 102 are shown, but other numbers of microphone elements (e.g., more or less) are also possible and can be expected.

[0032] Each microphone element 102 can detect sound and convert it into an audio signal. In some cases, the audio signal can be a digital audio output (e.g., a MEMS transducer). For other types of microphones, the audio signal can be an analog audio output, and components of the array microphone 100 (such as analog-to-digital converters, processors, and / or other components) can process the analog audio signal to ultimately generate one or more digital audio output signals. In some embodiments, the digital audio output signal can conform to the Dante standard for transmitting audio over Ethernet, or it can conform to other standards. In some embodiments, the processor of the array microphone 100 can form one or more pickup patterns based on the audio signals from the microphone elements 102, and the processor can generate a digital audio output signal corresponding to each pickup pattern. In other embodiments, the microphone elements 102 can output analog audio signals, and other components and devices external to the array microphone 100 (e.g., processors, mixers, recorders, amplifiers, etc.) can process these analog audio signals.

[0033] like Figure 1 As shown, the array microphone 100 includes a plurality of microphone boards 104 configured to include or support a plurality of microphone elements 102. The plurality of microphone boards 104 (also referred to as “units”) may be encapsulated in a housing 106. It should be understood that, for ease of illustration, the housing is... Figure 1 Each of the above three sections is shown in part only. Microphone element 102 may be mechanically and / or electrically coupled to microphone board 104. Microphone board 104 (also referred to as a “support”) may be a separate structure mechanically attached to housing 106 and electrically coupled to each other and / or to one or more processors or other electronic devices for receiving and processing audio signals captured by microphone element 102 (e.g., see [reference 3]). Figure 9 (System 300 in the text). The microphone board 104 may be made of a printed circuit board (“PCB”), a PCB substrate, or other suitable substrate or material. The housing 106 may be made of aluminum, plastic, or any other suitable material. While the illustrated embodiment shows the housing 106 having a generally rectangular shape, in other embodiments, the housing may have any other suitable shape or design. In some embodiments, two or more microphone boards 104 may be combined (e.g., side-by-side) to form a single unit, for example, to reduce the total number of boards 104.

[0034] Multiple microphone plates 104 can be configured to position microphone elements 102 in three-dimensional space such that they collectively form a multidimensional array configured to cover multiple frequency bands (e.g., 20 Hz ≤ f ≤ 20 kHz). Specifically, each microphone plate 104 may have a matched or uniform shape including multiple sides or surfaces for positioning the microphone elements 102 in different dimensions, and a bottom or back surface for positioning the entire plate 104 in an upright manner. For example, in the illustrated embodiment, the microphone plate 104 has a generally triangular shape, wherein three sides intersect to form three corners. A first side 108 of each plate 104 is attached to a mounting surface 106a of a housing 106, while the other two sides 110 and 112 are freestanding and substantially perpendicular to the mounting surface 106a. As shown, microphone elements 102 may be included on the freestanding sides 110 and 112 of the microphone plate 104, while the first side 108 (also referred to herein as the “planar side”) may not have microphone elements 102. This arrangement ensures that the microphone element 102 is positioned in free space, for example, away from any circuitry 106a or other parts of the housing 106 near the mounting surface. In other embodiments, the microphone board 104 may be configured in any other shape capable of implementing the technology described herein.

[0035] According to embodiments, the array microphone 100 can produce a substantially consistent frequency response across various scenarios or orientations, including, for example, whether mounted on a wall or other vertical surface, placed on a table, desktop, podium, or other horizontal surface, or attached to the ceiling. That is, regardless of array orientation, the audio pickup lobe of the array microphone 100 can be pointed towards the desired sound source while enhancing rear suppression and steering control, or isolating forward reception, thereby improving the array's ability to suppress irrelevant sound sources and reflections within the room and providing a high signal-to-noise ratio (SNR) in any dimension.

[0036] To illustrate, Figures 1 to 3B An array of microphones 100 arranged in a horizontal orientation is shown, or the mounting surface 106a of the housing 106 lies flat on a horizontal surface (not shown), while Figure 4 An array of microphones 100 arranged in a vertical orientation is shown, or mounting surface 106a is placed flat on a vertical surface. (See diagram.) Figure 5A and 5B As shown, a given sound source 113 can affect the array microphone 100 at different angles, or have different incident directions relative to the array, depending on whether the plate 104 is placed vertically or horizontally. For example, when the array microphone 100 is placed horizontally (as shown in the diagram), Figure 5B As shown), the sound source 113 may be pointed to one side 112 of the microphone board 104; when the array microphone 100 is placed vertically (as shown), the sound source 113 may be pointed to one side 112 of the microphone board 104. Figure 5AAs shown), the sound source 113 may be pointed to one side 114 of the microphone board 104, or perpendicular to the first axis 115 of the array (also referred to herein as the "array axis"), and as shown in the diagram. Figure 3A (As shown). In embodiments, the array microphone 100 can be configured using the microphone placement and beamforming techniques described herein to direct the main lobe or sound beam to any location within a plane 116 perpendicular to the array axis 115. In some embodiments, additional beamforming techniques can be used to direct the main lobe to any direction at any azimuth and elevation angle around a sphere surrounding the center of the array, thereby allowing the array microphone 100 to optimally capture the sound source 113 in any orientation. The array microphone 100 can also use similar techniques to isolate or suppress sound sources (e.g., unrelated speakers or other noise sources) from other directions within the plane 116 or the defined sphere, as described herein.

[0037] According to embodiments, dividing the microphone elements 102 onto multiple structurally and physically independent microphone boards 104 allows for more efficient use of copper wires or conductors and minimizes or reduces the impact of the overall array structure on the incident sound field. It should be understood that minimizing the structural footprint of the array microphones 100 also reduces diffraction, resonance, and geometric shading or masking effects that would otherwise occur in a three-dimensional array structure. In embodiments, the microphone boards 104 themselves are also configured to minimize interaction with the incident sound field by reducing the structural footprint of each board 104. For example, as shown, each microphone board 104 has a cutout or open center 117 to minimize the amount of PCB substrate or other material used to create the structure of the board 104. In some embodiments, the open center 117 can be configured (e.g., in size and shape) to be as large as possible while still leaving sufficient space on the board 104 for placing and / or connecting the microphone elements 102 and maintaining the structural integrity of the board 104. Similarly, the thickness of each microphone board 104 can be selected to further minimize interaction with the incident sound field while also maintaining the structural integrity and stability of the board 104.

[0038] In an embodiment, the microphone plate 104 may be linearly arranged along the length of the array microphone 100 or its housing 106, and perpendicular to the preferred or intended incident direction of the incoming sound waves, thereby forming a linear pattern along the first axis 115 (or common axis) of the array microphone 100. For example, as Figure 3AAs shown, a linear pattern can be formed by aligning the center 117 of each board 104 with the first axis 115 and arranging the boards 104 substantially parallel to each other, or parallel to the axis 119 orthogonal to the first axis 115 and parallel to the mounting surface 106a of the housing 106. As shown, the linear pattern configuration results in the plurality of microphone boards 104 including a central microphone board 104a, a first group of microphone boards 104b arranged in a first pattern on one side of the central microphone board 104a, and a second group of microphone boards 104c arranged in a second pattern on the opposite side of the central microphone board 104a, the second pattern being a mirror image of the first pattern.

[0039] According to an embodiment, the linear pattern formed by the microphone board 104 along the first axis 115 can be configured to use one or more beamformers or other audio processing techniques to place the microphone board 104 in a harmonic nesting configuration to cover multiple desired frequency bands. For example, the linear pattern formed by the microphone board 104 can be configured to operate in different octaves (e.g., 600-1200 Hz, 1200-2400 Hz, 2400-4800 Hz, etc.) within the covered multiple frequency bands, thereby making the overall beam pattern of the array microphone 100 substantially constant between the various octaves. In some embodiments, the linear pattern can be implemented using a subband-based scaling aperture (SSA) method, which uses a different array aperture for each octave so that octaves with gradually decreasing frequencies are processed by a gradually widened linear array. To enhance spatial resolution, the aperture of the linear array formed by the microphone board 104 can be doubled as it moves from a higher octave to the next lower octave (e.g., as shown in the image). Figure 7 As shown, and described in more detail below.

[0040] like Figure 3AAs shown, each microphone board 104 includes a selected number of microphone elements 102, with the central microphone board 104a including the largest number of microphone elements 102 (e.g., 9), while the other microphone boards 104b and 104c include a smaller number of microphone elements 102 (e.g., 3 or 5). In embodiments, each microphone board 104 is configured to include all the microphone elements 102 required to construct a functional array at a designated location on the board 104 along a first axis 115. Therefore, the exact number of microphone elements 102 included on each microphone board 104 may vary due to a variety of factors, such as the position of the microphone board 104 within a linear pattern formed by the plurality of microphone boards 104, the linear aperture of the entire array microphone 100, the multiple frequency bands covered by the array microphone 100, the size and / or type of the microphone elements 102, the size and / or shape of the microphone board 104, and / or the spacing between adjacent microphone boards 104, as described in more detail below. In this embodiment, since the total number of microphone elements 102 that may be included on any given microphone board 104 is nine or fewer, the audio signal captured by each microphone board 104 can in all cases be multiplexed as a TDM16 stream, or can be split into a TDM16 stream for the central microphone board 104a (which has the largest number of microphone elements 102) and a TDM8 stream for the remaining microphone boards 104b and 104c. This helps to minimize the use of copper wires or lines in and / or between each microphone board 104.

[0041] like Figure 3A As shown, each of the plurality of microphone boards 104 includes a first microphone element 102a, which is disposed on the first axis 115 or located at or near the center 114 of the microphone board 104. Figure 3B As further shown in the close-up view, due to its central location 114, the first microphone element 102a can be linearly arranged along the first axis 115 to form the same linear pattern as the microphone board 104. In various embodiments, the first microphone element 102a can be configured to collectively form the main array 118, which helps to produce consistent behavior during turning while maximizing the multiplexing of the microphone element 102a and minimizing the total number of microphones within the main array 118. For example, as... Figure 3B As shown, the main array 118 may consist of 11 first microphone elements 102a, which are arranged in four harmonic nested subarrays, each subarray including five specific first microphone elements 102a (as described below). Figure 7 (further details are provided below).

[0042] For further reference Figure 6For ease of illustration, an exemplary microphone plate 104 oriented relative to the XYZ axes is shown in the figure. Specifically, as shown, the center 114 of plate 104 is aligned with the center (0, 0, 0) of the XYZ axes, and the array axes (e.g., the first axis 115) are aligned with the X-axis. To align the rest of plate 104 with the XYZ axes, microphone plate 104 can be rotated about the first axis 115 such that sides 110 and 112 are aligned with the Z-axis and Y-axis, respectively. It should be understood that during use, microphone plate 104 can be oriented at different angles relative to the center of the XYZ axes depending on the orientation of the array microphone 100, for example, as Figure 5A and 5B As shown. Furthermore, although Figure 6 Specifically shown is the central microphone board 104a, and a similar principle can be used to place the microphone element 102 on one or more other microphone boards 104b and 104c.

[0043] According to an embodiment, each microphone board 104 includes a first linear array 120 arranged along a second axis 121 (e.g., Y axis) orthogonal to a first axis 115 (e.g., X axis) and a second linear array 122 arranged along a third axis 123 (e.g., Z axis) orthogonal to both the first axis 115 and the second axis 121, such as... Figure 6 As shown. On each board 104, the first linear array 120 includes a first microphone element 102a disposed on the first axis 115 and located at the center 114 of the board 104, and one or more second microphone elements 102b among a plurality of microphone elements 102 disposed on a second axis 121 orthogonal to the first axis 115. Similarly, the second linear array 122 on each board 104 includes the same first microphone element 102a and one or more third microphone elements 102c among a plurality of microphone elements 102 disposed on a third axis 123 orthogonal to both the first axis 115 and the second axis 121. In embodiments, it should be understood that the first microphone element 102a may be reused in each of the secondary arrays 120 and 122 to create the main array 118, thereby reducing the total number of microphone elements 102 included in the array microphone 100, thereby improving the efficiency and performance of the array while reducing cost and complexity.

[0044] Secondary arrays 120 and 122 can be configured, based on harmonic nesting technology, to form differential arrays along the second axis 121 and the third axis 123, respectively, as shown in... Figure 7 A more detailed description is available in the text. For example... Figure 6As shown, the first linear array 120 and the second linear array 122 can be arranged substantially perpendicular to each other and perpendicular to the main array 118 formed along the first axis 115. Furthermore, on each microphone board 104, the second linear array 122 along the third axis 123 can be configured as a mirror image of the first linear array 120 along the second axis 121. For example, as... Figure 6 As shown, the distance between the first microphone element 102a and the first element of the second microphone element 102b along the second axis 121 is d. Similarly, the distance between the first microphone element 102a and the first element of the third microphone element 102c along the third axis 123 is also d. For example, as... Figure 3A As shown, when comparing the microphone element 102 located above the first axis 115 with the microphone element 102 located below the first axis 115, it can be found that similar correspondences may exist for each of the other microphone elements 102b, 102c, and each of the other microphone boards 104b, 104c. In an embodiment, on each microphone board 104, the distance along the second axis 121 between the first microphone element 102a and each of one or more second microphone elements 102b can be configured based on corresponding octaves of multiple frequency bands, and the distance along the third axis 123 between the first microphone element 102a and each of one or more third microphone elements 102c can be configured based on the same octaves. Therefore, the array microphone 100 can be configured to provide corresponding differential arrays set along the orthogonal axes 121 and 123 of each microphone board 104.

[0045] In embodiments, using one or more beamforming techniques described herein, each differential array formed on microphone plate 104 can be configured to generate a first-order polar pattern oriented along a line defined by microphone elements 102 in the array (e.g., along a second axis 121 or a third axis 123), and can be pointed in a positive or negative direction. Furthermore, the first-order polar patterns generated by all or more microphone plates 104 can be combined to direct the overall audio pickup lobe of the array microphone 100 toward plane 116 (or...) using one or more beamforming techniques described herein. Figure 6 The array microphone 100 can be positioned in any direction transverse to the array axis (or the first axis 115) within the YZ plane, thereby providing improved directivity. The main array 118 can also be combined with one or more secondary arrays 120 and 122 to direct the overall audio pickup lobe in any direction of azimuth and elevation around a sphere surrounding the center of the array (e.g., the center microphone element 132), such that the array microphone 100 can cover, for example, a solid angle of four π spherical degrees.

[0046] In an embodiment, microphone elements 102 are arranged across microphone plates 104, using one or more beamforming techniques to collectively form a harmonic nested linear array. For example, multiple microphone elements 102 may be configured to form a first octave and a second octave across multiple microphone plates 104, the first octave covering a first subarray in the covered frequency bands, and the second octave covering a second subarray in the multiple frequency bands, wherein the first subarray is nested within the second subarray, for example, as... Figure 7 As shown. In this configuration, the first microphone elements 102a in the first subarray can be spaced a first distance along the first axis 115, while the first microphone elements 102a in the second subarray can be spaced a second distance along the first axis 115, the second distance being twice the first distance, thus enabling harmonic nesting between the first and second subarrays, as shown. Figure 7 As shown.

[0047] review Figure 3A Since each microphone board 104 includes a corresponding first microphone element 102a, the spacing or distance between adjacent microphone boards 104 along the first axis 115 can also be determined according to the harmonic nesting principle. This also means that the first linear arrays 120 located on the sides 112 of the board 104 can be harmonically nested with each other, and the second linear arrays 122 located on the sides 110 of the board 104 can also be harmonically nested with each other. In some embodiments, the first linear arrays 120 can be combined or aggregated to form a first harmonic nested linear array parallel to the second axis 121 of any given microphone board 104, and the second linear arrays 122 can be combined to form a second harmonic nested linear array parallel to the third axis 123 of any given microphone board 104. These first and second harmonic nested linear arrays can then be combined to form the main harmonic nested linear array of the array microphone 100, which can be oriented in any direction within a plane 116 perpendicular to the first axis 115 or the array axis. By aggregating the first and second linear arrays 120 and 122 with the main array 118, the resulting first-order polar pattern can be further steered relative to the array axis at any azimuth or elevation angle within a sphere centered on the array microphone 100. This process can be performed using conventional linear array beamformers (e.g., delay summation, differential, MVDR, etc.), as described herein. It can be understood that arranging the microphone elements 102 in harmonic nested subarrays (or nests) may be more efficient and economical, as one or more microphone elements 102 can be reused as part of multiple subarrays (or nests), thereby reducing the total number of microphone elements 102 required to cover the target octave band of the array microphone 100.

[0048] For further reference Figure 7 The following is illustrated according to an embodiment. Figure 1An exemplary harmonic nested microphone arrangement on the first plane 101 (or part thereof) of the array microphone 100. For example... Figure 3A As shown in the top view, the first plane 101 can be positioned on one side of the array microphone 100, for example, relative to a plane (not shown) that includes the first axis 115 and extends perpendicular to the axis 119, or otherwise bisect the array microphone 100, while the second plane 103 of the array microphone 100 can be positioned on the opposite side or half of the array microphone 100 (e.g., relative to the bisecting plane). Figure 7 In the diagram, for ease of explanation, the first plane 101 is shown located at... Figure 6 The XYZ axes are shown on the XY plane. For example, the orientation of all the microphone boards 104 in the array microphone 100 can be adjusted so that the center 114 of each board 104 is along the X-axis of the XY plane (e.g., ...). Figure 6 The first axis 115 shown is provided, and each plate 104 side 112 is aligned with the Y-axis of the XY plane (e.g., Figure 6 Align the second axis 121 shown in the figure to position the first plane 101 on the XY plane.

[0049] In the example shown, the second plane 103 of the array microphone 100 (although not shown) can be located on the XZ plane of the XYZ axes, because the second plane 103 is defined by the Z axis (e.g., along the XZ plane) and the Z axis (e.g., along the XZ plane). Figure 6 The third axis 123 shown is aligned with the side 110 of the plate. In an embodiment, the second plane 103 of the array microphone 100 may be a mirror image of the first plane 101, because the second linear array 122 disposed on the side 110 of each microphone plate 104 is a mirror image of the first linear array 120 disposed on the side 112 of the same plate 104. Therefore, for the sake of brevity, the following refers to... Figure 7 The description will primarily concern the microphone arrangement disposed on the first plane 101. However, it should be understood that the second plane 103 has the same or similar characteristics as the first plane 101, and a harmonic nested microphone arrangement can be formed on the second plane 103 of the array microphone 100 using similar techniques.

[0050] Now refer to Figure 3B and Figure 7 Describe the harmonic nesting arrangement of microphone elements 102a and 102b on the first plane 101 of the array microphone 100. (As follows) Figure 3B As shown, the first microphone element 102a may include a first group of elements 124, which are spaced apart from each other by a first distance D1 to form a first subarray (or nesting), which is configured to cover the first or Nth octave band. Similarly, as... Figure 3BAs shown, the first microphone element 102a also includes a second set of elements 126, which are configured to form a second subarray by spacing the elements 126 apart by a second distance (twice the first distance D1) to cover a second or next lower octave (e.g., the (N-1)th octave). Similarly, Figure 3B It is also shown that the first microphone element 102a includes a third set of elements 128, which are configured to form a third subarray by spacing the elements 128 apart by a third distance (which is twice the second distance or four times the first distance D1) to cover a lower third octave (e.g., the (N-2)th octave). Similarly, as... Figure 3B As shown, the first microphone element 102a also includes a fourth group of elements 130, which is configured to form a fourth subarray by spacing the elements 130 apart by a fourth distance (which is twice the third distance or eight times the first distance D1) to cover a lower fourth octave (e.g., the (N-3)th octave). In other words, the distance or spacing between the first microphone elements 102a can be halved for each octave frequency value, or increased by a factor of 2 for each reduced octave. Thus, the microphone elements 124 used to cover the highest or Nth octave are closest to each other, or form the smallest aperture size, while the microphone elements 130 used to cover the lowest octave (e.g., the (N-3)th octave) and below are furthest from each other, or form the largest aperture size.

[0051] In a preferred embodiment, a harmonic nesting technique is used to select the distance between adjacent first microphone elements 102a in the main array 118, such that the linear pattern harmonics formed by the first, second, third, and fourth sub-arrays are nested, as shown below. Figure 3B As shown. This arrangement may be more efficient and economical because one or more first microphone elements 102a can be reused as part of multiple subarrays, thereby reducing the total number of microphone elements 102a required to cover the target octave band of the array microphone 100. Specifically, since the placement positions of the second and third subarrays are different times (e.g., 2 and 4 times) the distance D1 between the first microphone elements 102a in the first subarray, the first subarray can be nested within the second and third subarrays, and the second subarray can be nested within the third subarray, as shown. Figure 7 As shown. Therefore, some of the first microphone elements 102a can be reused multiple times in a nested manner. For example, as Figure 3B and Figure 7As shown, the central element 132 of the plurality of first microphone elements 102a can be reused in each of the first, second, third, and fourth subarrays. Another example is that at least three elements 124 in the first subarray also constitute part of the second subarray, and at least three elements 126 in the second subarray also constitute part of the third subarray.

[0052] Various factors can be considered to determine the minimum distance value D1 between the first microphone elements 102a along the first axis 115, thereby determining the distance between adjacent microphone plates 104. In some embodiments, the distance between adjacent microphone plates 104 along the first axis 115 can be configured based on frequency values ​​contained in multiple frequency bands covered. In this case, the distance D1 between the first microphone elements 102a can be selected based on the frequency bands in the array microphone 100 that require spatial sampling. In some embodiments, the distance between adjacent microphone plates 104 along the first axis 115 can be configured based on the linear aperture size of the array microphone 100. In this case, the distance D1 between the first microphone elements 102a can be selected based on the required linear array aperture size and the total number of first microphone elements 102a used to form the linear array pattern (or main array 118), thereby giving the array microphone 100 a scalable geometry that can be reconfigured to meet the design requirements of a specific application. Other design considerations can also determine the value of D1, including, for example, the required frequency null location, the required amount of electrical delay, spatial sampling density, criteria for avoiding spatial aliasing, and processing overhead. In one exemplary embodiment, the distance D1 is approximately 150 millimeters (mm) along the array axis.

[0053] like Figure 7 As shown, the first plane 101 also includes second microphone elements 102b (also referred to herein as "additional microphone elements") arranged orthogonally to the first microphone element 102a, or along a second axis 121 of the corresponding microphone board 104, to create a differential array for increasing directivity at various target frequencies or octaves. Specifically, on each microphone board 104, a second microphone element 102b is added to replicate the first microphone element 102a contained thereon at a position relative to the first axis 115, but the second microphone element 102b is positioned on the second axis 121, which is orthogonal to the corresponding first microphone element 102a and perpendicular to the first axis 115, for example... Figure 6 and 7 The Y-axis is shown in the diagram (also referred to as the "orthogonal axis" in this text).

[0054] In an embodiment, on each microphone board 104, each second microphone element 102b and the first microphone element 102a are replicated to form a microphone group or differential pair, which is configured to operate within an octave band covered by the replicated first microphone element 102a. For example, in each microphone group, the spacing or distance between the first microphone element 102a and the corresponding second microphone element 102b along the orthogonal axis 121 can be selected based on the frequency octave bands covered by the group. Furthermore, by acoustically combining the two microphone elements 102a and 102b to create a new pickup pattern for the microphone group (e.g., using appropriate beamforming techniques), the first and second microphone elements 102a and 102b of each microphone group can be considered as individual microphone elements of the array microphone 100.

[0055] Furthermore, in embodiments, microphone groups from different microphone boards 104 can be combined together as a subarray to generate one or more combined outputs for the array microphone 100. For example, all microphone groups configured to cover a first octave (e.g., N) can be combined or aggregated across multiple microphone boards 104 to create a subarray operating within that octave (e.g., using appropriate beamforming techniques), such as... Figure 7 Subarray 1 is shown in the diagram. Figure 7 As shown, the first plane 101 of the array microphone 100 may include four groups of microphones 134, 136, 138, and 140, and the microphone groups in each group 134, 136, 138, and 140 can be combined to create subarrays 1, 2, 3, and 4 with specific octave bands, respectively. These subarrays (also referred to as “differential arrays”) can be further aggregated to create an overall output with a substantially constant beamwidth for the array microphone 100.

[0056] More specifically, the first microphone group 134 includes an element 124 from a first microphone element 102a, which is disposed along a first axis 115 to form a first subarray covering a first or Nth octave band. The first microphone group 134 also includes a second microphone element 102b, which is added to replicate the first subarray along a second axis of the corresponding microphone plate 104. In each microphone group 134, the second microphone element 102b is disposed at a first distance D2 from the corresponding first microphone element 102a. Similarly, the second microphone group 136 includes an element 126 from a first microphone element 102a, which is disposed along the first axis 115 to form a second subarray covering a second or (N-1)th octave band. The second microphone group 136 also includes a second microphone element 102b, which is added to replicate the second subarray along a second axis 121 of the corresponding microphone plate 104. In each microphone group 136, the second distance between the second microphone element 102b and the corresponding first microphone element 102a is twice the first distance D2. Similarly, the third microphone group 138 includes an element 128 from the first microphone element 102a, which is arranged along a first axis 115 to form a third subarray covering a third or (N-2) octave band. The third microphone group 138 also includes a second microphone element 102b, which is added to replicate the third subarray along a second axis 121 of the corresponding microphone board 104. In each microphone group 138, the third distance between the second microphone element 102b and the corresponding first microphone element 102a is four times the first distance D2. Finally, the fourth microphone group 140 includes an element 130 from the first microphone element 102a, which is arranged along a first axis 115 to form a fourth subarray covering a fourth or (N-3) octave band. The fourth microphone group 140 also includes a second microphone element 102b, which is added to replicate the fourth subarray along the second axis 121 of the corresponding microphone board 104. In each microphone group 140, the fourth distance between the second microphone element 102b and the corresponding first microphone element 102a is approximately 6.67 times the first distance D2.

[0057] Therefore, similar to the distance between adjacent first microphone elements 102a along the first axis 115, the distance between microphone elements in a given differential pair decreases by half with each octave frequency value, or increases by a factor of two (i.e., 2) with each decreasing octave, except for the highest frequency. In an embodiment, the distance D2 between the first microphone element 102a and the second microphone element 102b in each of the first plurality of microphone groups 134 can be equal to half the wavelength of the desired frequency from the octave (i.e., the Nth octave) covered by group 134, for example, to produce a null at the desired frequency. The distance D2 can also be selected to optimize the cardioid configuration when the first microphone elements 102a and the second microphone element 102b of a given microphone group are combined to produce a combined output, as described below. In an exemplary embodiment, the D2 distance is approximately 7.5 millimeters (mm) along the corresponding second axis 121.

[0058] like Figure 7 As shown, multiple microphone boards 104 have two or more microphone groups co-located along orthogonal axes 121 because they share the same first microphone element 102a. This arrangement is at least partly due to the harmonic nesting of the first microphone elements 102a along the first axis 115, and the fact that multiple first microphone elements 102a cover multiple octaves. More specifically, each first microphone element 102a configured to cover multiple octaves can be replicated by the same number of second microphone elements 102b, which are positioned at appropriate (e.g., frequency-dependent) distances along the same orthogonal axes 121 of the corresponding microphone boards 104, thereby creating co-located microphone groups. In other words, the total number of second microphone elements 102b that can be located on the same orthogonal axis 121 (or in the first linear array 120) depends on the number of octaves covered by the first microphone elements 102a in the linear array 120. For example, in Figure 7 In this configuration, the central microphone element 132 is contained within all four sub-arrays and is therefore used to cover all four octaves (e.g., N, N-1, N-2, and N-3). Thus, as... Figure 7 As shown, the central microphone element 132 is paired with four different second microphone elements 102b to provide coverage of each of the four octaves. Conversely, as also... Figure 7 As shown, each first microphone element 102a located at the far end of the first plane 101 is paired with only one second microphone element 102b, because these first microphone elements 102a are only used to cover one octave (e.g., N-3), and are therefore contained in only one subarray (e.g., subarray 4).

[0059] In this embodiment, multiple microphone groups formed by microphone elements 102 on the first plane 101 and the second plane 103 are arranged orthogonally to the first axis 115 (or arranged along the second orthogonal axis 121 and the third orthogonal axis 123 respectively). Figure 6 As shown), to maintain the linear array pattern created by the first microphone element 102a along the first axis 115. For example, the first microphone element 102a may constitute the main array 118 of the array microphone 100 (e.g., as shown). Figure 3B (as shown), and the second and third microphone elements 102b and 102c can be disposed in the array microphone 100 to form multiple secondary or differential arrays (e.g., Figure 6 The first and second linear arrays 120 and 122 shown are orthogonal to the main array 118 along two different dimensions or axes. This multidimensional arrangement of the microphone elements 102 allows the array microphone 100 to have a relatively thin profile, while using appropriate beamforming techniques in the plane 116 (or... Figure 6 The array microphone 100 can provide directivity at any location within the YZ plane (or at any location within a sphere centered on the array). In some cases, the total length of the array microphone 100 may be primarily determined by the size of the main array 118, or more specifically, by the linear aperture size formed by the first microphone elements 102a and other physical characteristics of the first microphone elements 102a, as well as the amount of spacing (e.g., D1 or a multiple thereof) between adjacent first microphone elements 102a along the first axis 115.

[0060] Other dimensions of the array microphone 100 (e.g., the overall depth or height / width along axis 119) can be determined by the number of differential pairs included on the orthogonal axes 121 and 123 of the microphone board 104 and the spacing between adjacent microphone elements along each orthogonal axis (e.g., as shown in the figure). Figure 6(As shown). The exact number of differential pairs included in array 100 may depend on the total number of octaves that array microphone 100 is to cover, which in turn can determine the distance between each layer, as described herein. In some cases, the number of differential pairs or the octaves covered may be determined by the physical limitations of the device housing of array microphone 100 (e.g., the maximum depth or height of housing 106). In the illustrated embodiment, the overall height and depth of array microphone 100 may be determined by factors such as the size and shape of microphone plate 104, the length or linear aperture size of the first and second linear arrays 120 and 122 respectively, the amount of space (e.g., D2 or a multiple thereof) between adjacent second microphone element 102b along the second axis 121 and adjacent third microphone element 102c along the third axis 123, and / or other physical characteristics of microphone elements 102b and 102c. While the illustrated embodiment shows a four-layer differential pair configured for four different octaves (e.g., N, N-1, N-2, N-3) to provide enhanced directivity, other embodiments may include more layers to cover more octaves, thereby increasing the height and depth of array 100, or include fewer layers to cover fewer octaves, thereby reducing the array height and depth.

[0061] To illustrate, Figure 8 A first plane 201 or portion thereof of another exemplary array microphone 200 is depicted, which has a smaller aperture size but other configurations are substantially similar to the array microphone 100 according to an embodiment. For example, the array microphone 200 may have a linear aperture size approximately half that of the array microphone 100. In embodiments, to accommodate the smaller linear aperture size, the array microphone 200 may use scalable geometry techniques described herein, comprising fewer microphone plates 204 than the array microphone 100 (e.g., 9 instead of 11). For example, the microphone plates 204 and the microphone elements 202 thereon may be harmonic nested like the microphone elements 102 by subdividing the linear aperture size into four harmonic nested subarrays, each containing five microphones. However, the minimum distance value D1* between the first microphone elements 202a positioned along the common axis 215 of the array microphone 200 may be smaller than the distance value D1 used for the array microphone 100. Furthermore, due to the smaller number of microphone plates 204 overall, a fourth subarray may be configured to completely overlap with the third subarray or positioned on the same microphone plate 104, as... Figure 8 As shown. In various embodiments, the array microphone 200 can maintain low-frequency directivity with minimal performance loss (e.g., due to self-noise, etc.) despite the subarrays overlapping each other.

[0062] Figure 9An exemplary audio system 300 according to an embodiment is shown. The audio system 300 includes an array microphone 302 similar to an array microphone 100 (or array microphone 200), a beamformer 304, and an output generation unit 306. The array microphone 302 may include... Figure 1 The array microphone 100 shown includes a microphone board 104 and microphone elements 102 included on each board 104, or other microphones designed according to the techniques described herein. A beamformer 304 may be in communication with the array microphone 302 and may include one or more components for processing audio signals received from the array microphone 302. An output generation unit 306 may be in communication with the beamformer 304 and may be used to process output signals received from the beamformer 304 to generate an output via, for example, a loudspeaker, television broadcast, etc.

[0063] The various components of the audio system 300 can be implemented using software (such as a computing device with a processor and memory) and / or hardware (e.g., discrete logic circuits, application-specific integrated circuits (ASICs), programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.) executable by one or more computers. For example, some or all of the components of the beamformer 304 can be implemented using discrete circuit devices and / or using one or more processors (e.g., audio processors and / or digital signal processors) (not shown) to execute program code stored in memory (not shown), which is configured to perform one or more processes or operations described herein. Therefore, in embodiments, the audio system 300 may include one or more processors, memory devices, computing devices, and / or Figure 9 Other hardware components are not shown. In a preferred embodiment, system 300 includes at least two independent processors, one for merging and formatting microphone elements, and the other for implementing DSP functions.

[0064] Beamformer 304 can be used to apply appropriate beamforming techniques to the audio signals captured by the microphone elements of array microphone 302 to create desired pickup patterns, such as first-order polar patterns (e.g., cardioid, supercardioid, hypercardioid, etc.), and / or to steer the polar pattern at a desired angle relative to the array axis to obtain additional directivity. For example, in some embodiments, beamformer 304 may be configured to combine audio signals captured by each microphone element positioned on a first axis or main axis of array microphone 302 to form a main array output; combine audio signals captured by microphone elements on the first axis with those captured by differential microphone elements positioned on different orthogonal axes of array microphone 302 to form an output for each differential pair; for each orthogonal plane of array microphone 302, combine the differential pair outputs of that plane to form a subarray output of a specific octave; combine the subarray outputs of each orthogonal plane to create a linear array output having a first-order polar pattern (e.g., cardioid pickup pattern) pointing along the central axis of that plane; combine the linear array outputs of two orthogonal planes to generate a directional output pointing in any direction or angle within a plane perpendicular to the first axis of the array; and combine one or more linear array outputs with the main array output to generate a directional output pointing in any direction or angle around a sphere centered on the center of the array. Beamformer 304 can be configured to combine the received audio signals and generate a steering output using any suitable beamforming algorithm, including, for example, delay calculation and techniques, weighted calculation and techniques, sum and difference techniques, filtering calculation and techniques, minimum variance distortionless response (“MVDR”) techniques, first-order differential techniques, or any combination thereof.

[0065] Figure 10 The array microphone 302 and beamformer 304 of the audio system 300 are shown in more detail. For ease of explanation, the array microphone 302 will be described with reference to the XYZ axes, or it will be assumed that the array microphone 302 is aligned with the XYZ axes, for example, by aligning the center 114 of the microphone plate 104 with the X-axis and aligning the edges 112 and 110 of the plate 104 with the Y-axis and Z-axis, respectively (e.g., as shown in Figure 102). Figure 6 and 7 (As shown). The Y-axis can coincide with a first plane of the array microphone 302 that is orthogonal to the first axis (e.g., first plane 101), while the Z-axis can coincide with a second plane of the array microphone 302 that is orthogonal to both the first axis and the first plane (e.g., second plane 103).

[0066] As shown in the figure, the array microphone 302 includes a plurality of first microphone elements 302a arranged along a main axis or a first axis aligned with the X-axis, such that the coordinates of each first microphone element 302a have zero values ​​along both the Y-axis and the Z-axis (e.g., similar to those arranged in a configuration where...). Figure 3BThe first microphone element 102a is shown on the first axis 115. Furthermore, the array microphone 302 includes a plurality of second microphone elements 302b disposed on a second axis aligned with the Y-axis of the microphone board, such that the coordinates of each second microphone element 302b have zero values ​​along both the X-axis and Z-axis of its respective microphone board (e.g., similar to those disposed on the first axis 115). Figure 6 The array microphone 302 also includes a plurality of third microphone elements 302c disposed on a third axis aligned with the Z-axis of the microphone board, such that the coordinates of each third microphone element 302c have zero values ​​along the X-axis and Y-axis of its respective microphone board (e.g., similar to...). Figure 6 The third microphone element 102c is disposed on the Z-axis. In an embodiment, the second microphone element 302b can be arranged to form a mirror image of the third microphone element 302c, such that the Y value of the second microphone element 302b on a given microphone board has the same value as the Z value of the corresponding third microphone element 302c disposed on the same microphone board (e.g., as shown in the image). Figure 3A (As shown).

[0067] According to an embodiment, beamformer 304 may include a plurality of individual beamformers or beamforming components configured to combine audio signals received from array microphone 302 and generate an audio signal directed toward a desired audio source (e.g., Figure 5A and Figure 5B The beamformer 304 controls the output of a sound source 113 and / or generates nulls at selected locations. In some embodiments, the individual beamforming components may be interconnected, for example, to provide the output of one beamforming component as the input of another. In some embodiments, although not shown, beamformer 304 includes multiple instances of a given beamforming component, for example, to customize the component to specific characteristics of the microphone elements or subarrays coupled thereto (e.g., microphone spacing, coverage frequency octaves, etc.). Beamformer 304 may also perform other beamforming techniques or combinations thereof to provide the desired output.

[0068] As shown in the figure, beamformer 304 includes a main beamforming component 308, which is configured to receive audio signals captured by a first microphone element 302a and combine these signals to generate a main array (e.g., along the X-axis) Figure 3B The main array 118) contains the main subarray outputs. The main beamforming component 308 (or "main beamformer") can be configured to generate a specific octave band output for each harmonic nested subarray formed by the main array. The main beamformer 308 can also be configured to combine the main and subarray outputs to generate a main array output with a first-order polar pattern oriented along the array axis. For example, the main array outputs can be along... Figure 3A The axis 119 in the diagram points in any direction. It should be understood that the polarity of the main array output can be omnidirectional in the YZ plane. In an embodiment, the main beamformer 308 can be configured to generate these main subarray outputs using one or more beamforming algorithms, such as delay calculation techniques, filtering calculation techniques, delay differential techniques, amplitude masking techniques, and minimum variance distortionless response (“MVDR”) techniques.

[0069] Beamformer 304 also includes two differential pair beamforming components 310 and 312, respectively, for each orthogonal axis of the microphone panels included in array microphone 302. More specifically, the first differential pair beamforming component 310 (or "first differential beamformer") can be configured to combine the audio signals captured by each differential pair included on the Y-axis of each microphone panel. Similarly, the second differential pair beamforming component 312 (or "first differential beamformer") can be configured to combine the audio signals captured by each differential pair included on the Z-axis of each microphone panel. Each differential beamformer 310 and 312 can generate one or more differential pair outputs for each microphone panel, depending on the number of differential pairs included thereon. For example, for Figure 3A The central microphone board 104a shown can generate a total of four differential outputs from each differential beamformer 310 and 312, corresponding to four differential pairs formed along the Y-axis and Z-axis, respectively. Conversely, each of the other microphone boards 104b and 104c can have one to three differential pairs of outputs per axis.

[0070] According to an embodiment, the first differential beamformer 310 may be further configured to combine Y-axis differential pair outputs generated across multiple microphone boards to create a specific octave-length output for each harmonic nested subarray formed by the microphone boards in a first orthogonal plane. Similarly, the second differential beamformer 312 may be further configured to combine Z-axis differential pair outputs generated across multiple microphone boards to create a specific octave-length output for each harmonic nested subarray formed by the microphone boards in a second orthogonal plane. That is, each subarray output generated by the differential beamformers 310 and 312 can be configured to cover a specific octave-length of the covered frequency band. In an embodiment, the differential beamformers 310 and 312 can be configured to generate these differential subarray outputs using one or more beamforming algorithms, such as delay calculation techniques, filtering calculation techniques, delay differential techniques, amplitude masking techniques, and minimum variance distortionless response (“MVDR”) techniques.

[0071] Beamformer 304 also includes two directional beamformers 314 and 316, configured to combine the master subarray output generated by the master beamformer 308 with the corresponding differential subarray output generated by each differential beamformer 310 and 312, thereby creating a linear array output for each orthogonal plane of the array microphone 302. Specifically, the first directional beamformer 314 may be configured to combine the master subarray output with the corresponding Y-axis differential subarray output provided by the first differential beamformer 310. For example, each master subarray output may be combined with a Y-axis subarray output corresponding to the same octave. Similarly, the second directional beamformer 316 may be configured to combine the master subarray output with the corresponding Z-axis differential subarray output provided by the second differential beamformer 312. For example, each master subarray output may be combined with a Z-axis subarray output corresponding to the same octave. The linear array output generated by the first directional beamformer 314 may have a first-order polarization pointing along the Y-axis of a first orthogonal plane (e.g., the XY plane), while the linear array output generated by the second directional beamformer 316 may have a first-order polarization pointing along the Z-axis of a second orthogonal plane (e.g., the XZ plane). In embodiments, the directional beamformers 314 and 316 may be configured to perform pattern forming and / or create various subarray outputs using any suitable beamforming algorithm, including, for example, sum-difference techniques (e.g., such as...). Figure 11 (as shown), first-order difference combination techniques (e.g., such as) Figure 12 (as shown) or any combination thereof.

[0072] As shown, beamformer 304 also includes a steerable beamforming component 318, which is configured to combine the linear array outputs received from the first and second directional beamformers 314 and 316 to generate a steerable output. In embodiments, the steerable beamforming component 318 (or “steerable beamformer”) may be configured to provide additional control over the array outputs about or transverse to the array axis. For example, due to the multidimensional placement and harmonic nesting of microphone elements 302a, 302b, and 302c, the steerable beamformer 318 may be configured to create a directional output having any first-order polarity (e.g., cardioid, annular, etc.) and may be steered in any direction within a plane perpendicular to the first axis (e.g., the YZ plane). The directional beamformer 318 also receives the main array output from the main beamformer 308 and can be configured to combine the main array output with directional outputs from beamformers 314 and 316 to generate a directional output oriented at an arbitrary angle relative to the array axis (e.g., the X-axis), or oriented in any direction at any azimuth or elevation angle around a sphere centered on the array's center. The directional beamformer 318 may include combiners, etc., for combining various outputs together to generate a directional output for the overall array microphone 302. In embodiments, the directional beamformer 318 may be configured to combine two directional outputs using any suitable beamforming algorithm, including, for example, weighted summation (or amplitude summation) techniques, filtering techniques, and differential techniques.

[0073] Therefore, beamformer 304 can be configured to apply array processing techniques (e.g., beamformers 308, 310, and 312), combined with secondary beamforming processing techniques (e.g., beamformers 314 and 316), and a tertiary beamforming step using amplitude calculation techniques, to provide stronger control over the array or the audio pickup lobe with the highest sensitivity. In embodiments, due to the linear independence of the three beamforming steps, the operating sequence of the components of beamformer 304 may be agnostic. For example, since the microphone elements within array microphone 302 are positioned on different axes, the audio signals captured by these elements can be processed along any axis in any order. Therefore, although Figure 10 The components of beamformer 304 are shown arranged in a specific order, but in other embodiments, one or more components of beamformer 304 may be executed in different locations or in different orders. For example, in some embodiments, differential beamformers 310 and 312 and main beamformer 308 may be executed last, for example, after directional beamformers 314 and 316 and steering beamformer 318 have operated.

[0074] Figure 11 An exemplary sum-difference beamformer 400 is shown, which, according to an embodiment, can be used to implement... Figure 10All or part of any one of the beamformers 310, 312, 314, and 316. Generally, beamformer 400 can be configured to combine the first and second audio inputs 402 using appropriate sum and difference beamforming techniques to generate a combined audio output signal with directional polarity.

[0075] In some embodiments, audio input 402 may be audio signals captured by differential pairs located on each microphone board of array microphone 302, and each differential pair may be combined using beamformer 400 to form, for example, a cardioid element with a narrower lobe (or pickup pattern), in contrast to the individual microphone elements of array microphone 302 having a full omnidirectional polarity pattern. For example, a first audio input 402 may include audio signals captured by a first microphone element 302a on each microphone board, while a second audio input 402 may include audio signals captured by a second microphone element 302b arranged on a first orthogonal axis of the same microphone board, or audio signals captured by a third microphone element 302c arranged on a second orthogonal axis of the same microphone board.

[0076] In other embodiments, audio input 402 may include a subarray output received from one of the main beamformer 308 and differential beamformers 310 and 312 to cover the same coverage octave. In this case, beamformer 400 may be configured to use sum-difference beamforming techniques to combine the subarray outputs to form a directional output dedicated to the frequency octaves covered by input 402 and to form a first-order mode in the corresponding orthogonal plane of array microphones 302. For example, first audio input 402 may include a main subarray output received from main beamformer 308, while second audio input 402 may include a differential subarray output received from one of differential beamformers 310 and 312, corresponding to the same octave as first audio input 402. The specific beamforming technique used to combine the subarray signals may vary depending on how the corresponding subarrays are formed or how the microphone elements are arranged within the subarray (e.g., linear array, orthogonal array, side array, end-fire array, etc.). For example, audio signals received from microphone elements arranged in a linear or side array can be summed to generate a subarray signal. Other techniques can be used for other types of subarrays.

[0077] like Figure 4As shown, first and second audio inputs 402 are provided to a summing component 404 and a differential component 406 of a beamformer 400. The summing component 404 can be configured to calculate the sum of the first and second audio signals (e.g., input 1 + input 2) to generate a combined or summed output of the audio input pairs 402. The differential component 406 can be configured to subtract the second audio signal from the first audio signal (e.g., input 1 - input 2) to generate a differential signal or output of the first and second audio inputs 402. For example, the summing component 404 may include one or more adders or other summing elements, while the differential component 406 may include one or more inverse summing elements.

[0078] As shown, beamformer 400 also includes a correction component 408 for correcting the differential output generated by differential component 406. Correction component 408 can be configured to correct the differential output to obtain a gradient response resulting from differential calculation. For example, the gradient response could provide a slope of 6 dB per octave for the frequency response of audio input 402. To generate a first-order polar pattern (e.g., cardioid) for audio input pair 402 over a wide frequency range, the differential output must be corrected to have the same amplitude as the summed output. In a preferred embodiment, correction component 408 applies a correction value of (c*d) / (j*ω) to the differential output to obtain corrected differential outputs for the two audio inputs 402 (e.g., (Mic 1 – Mic 2)*((c*d) / (j*ω))), where c equals the speed of sound in air at 20 degrees Celsius, d equals the distance between the first and second microphones (e.g., D² or a multiple thereof), and ω equals the angular frequency. In some cases, a second amplitude correction may be performed to match the sensitivity of the differential component to the sensitivity of the summed component.

[0079] The beamformer 400 also includes a combiner 410 configured to combine or add the summed output generated by the summing component 404 with the corrected differential output generated by the correction component 408. Thus, the combiner 410 generates a combined output signal with a directional polarity (e.g., cardioid) for the audio input pair 402, such as... Figure 4 As shown.

[0080] Figure 12 An exemplary pattern-forming beamformer 500 is shown, which, according to an embodiment, can be used to implement... Figure 10The beamformers 308, 310, 312, 314, and 316 shown are functionally complete or partially functional. Beamformer 500 can be configured to combine outputs from harmonic nested microphone elements 302a, 302b, and 302c to form a cardioid output or other directional output with a first-order polar pattern. For example, beamformer 500 can receive outputs from corresponding nested or subarrays formed along one or more axes of array microphone 302. In some embodiments, beamformer 500 may be included in beamformers 314 and 316 and used to combine subarray outputs received from main beamformer 308 and corresponding differential beamformers 310 or 312 to create a first-order directional output for each orthogonal plane of array microphone 302.

[0081] In an embodiment, beamformer 500 may be configured to use cross-filtering techniques to create a first-order polar pattern. As shown, beamformer 500 includes multiple filters 502, 504, 506, and 508, each configured to receive audio signals from a different group of microphone elements. Specifically, very high-pass filter 502 is configured to receive audio signals from microphone elements or subarrays configured to cover very high frequencies (e.g., greater than about 4 kHz). High-frequency bandpass filter 504 is configured to receive audio signals from microphone elements or subarrays configured to cover high frequencies (e.g., from about 2 kHz to about 4 kHz). Intermediate-frequency bandpass filter 506 is configured to receive audio signals from microphone elements or subarrays configured to cover intermediate or mid-range frequencies (e.g., from about 1 kHz to about 2 kHz). Low-pass filter 508 is configured to receive audio signals from microphone elements or subarrays configured to cover low frequencies (e.g., less than about 1 kHz). The cutoff frequencies of filters 502, 504, 506, and 508 can be selected based on the specific frequency response characteristics of the corresponding microphone element group, such as the location of the frequency null, the desired frequency response of the microphone array, etc.

[0082] In various embodiments, filters 502, 504, 506, and 508 can be analog or digital filters (e.g., digital finite impulse response (FIR) filters on a digital signal processor (DSP), etc.). Although Figure 12 Four filters are shown, but in other embodiments, beamformer 500 may contain more or fewer filters. In other embodiments, beamformer 500 may be configured to include different combinations of filters, such as multiple bandpass filters or any other combination.

[0083] As shown in the figure, the filtered outputs of filters 502, 504, 506, and 508 can be provided to the summing element 510 of beamformer 500. The summing element 510 can be configured to combine or sum the filtered outputs to generate a combined output signal that can represent a cardioid output or other first-order polar pattern of the input microphone element.

[0084] Therefore, the technology described herein provides an array microphone with improved directivity in the transverse direction to the array axis, thus offering a higher level of control over where the array most effectively collects sound, and its geometry allows for minimal diffraction and resonance. For example, the array microphone's structure is broken down into individual units (or microphone boards) to use a minimal amount of interfering material (e.g., a PCB substrate) while still placing the microphone elements in a multi-dimensional configuration. Furthermore, due to the array microphone's arrangement and overall geometry, the main lobe, or the beam with the highest sensitivity, can be positioned in any direction within a plane perpendicular to the array axis. In some cases, the array microphone described herein can be used to simultaneously generate multiple independent audio channels, each customized to capture a specific speaker or audio source, while eliminating room noise, other speaker noise, and other irrelevant sounds. For example, array microphones can be used for stage or live music enhancement to provide selective coverage of the stage or audience, or to isolate ambient sounds from the game audio in a live sports environment. Therefore, array microphones not only offer better directivity in wideband audio applications (e.g., 20 Hz ≤ f ≤ 20 kHz), but also better signal-to-noise ratio (SNR) and acoustic echo cancellation (AEC) characteristics. The techniques described herein also provide array microphones with greater flexibility (e.g., compared to existing linear arrays), allowing for expanded functionality. For example, the pattern forming techniques described herein enable array microphones to be used as center-side stereo arrays or for highly directional center-side stereo generation, and can improve spatialization in simple two-channel recordings (e.g., adding height information). As another example, the array geometry described herein can allow for first-order stereo reverberation collection with only minor alterations to the signal flow. In some cases, the techniques described herein can be used in integrated or UC devices to minimize coupling between transmitting and receiving acoustic systems.

[0085] Return to reference Figure 9 In various embodiments, the audio system 300 may also include Figure 9 Various components not shown (e.g., one or more speakers, displays, computing devices, and / or cameras). Furthermore, one or more components in system 300 may include one or more digital signal processors or other processing components, controllers, wireless receivers, wireless transceivers, etc., although not shown or mentioned above. It should be understood that... Figure 9The components shown are merely exemplary, and any number, type, and placement of the various components in system 300 are conceivable and possible.

[0086] One or more components of the audio system 300 can communicate with one or more other components of the system 300 via wired or wireless means. For example, the array microphone 302 can use a wired or wireless connection to send multiple audio signals to a beamformer 304, an output generation unit 306, a separate audio processor (not shown), or a computing device including one or more of these. In some embodiments, one or more components of the audio system 300 can communicate with one or more other components of the system 300 via a suitable application programming interface (API). For example, one or more APIs can enable components of an audio processor to transfer audio and / or data signals between them.

[0087] In some embodiments, one or more components of the audio system 300 may be combined into a single unit or device, or deployed in a single unit or device. For example, all components of the audio system 300 may be contained in the same device, such as microphone 302, or a computing device containing microphone 302. As another example, output generation unit 306 may be included in, or combined with, beamformer 304 and / or microphone 302. In some embodiments, the audio system 300 may take the form of a cloud-based system or other distributed system, such that the components of system 300 may or may not be physically close to each other.

[0088] Components of the audio system 300 can be implemented in hardware (e.g., discrete logic circuits, application-specific integrated circuits (ASICs), programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), microprocessors, etc.), in software executed by one or more servers or computers or other computing devices with processors and memory (e.g., personal computers (PCs), laptops, tablets, mobile devices, smart devices, thin clients, etc.), or in a combination of hardware and software. For example, some or all of the components of microphone 302, beamformer 304, and / or output generation unit 306 can be implemented using discrete circuit devices and / or one or more processors (e.g., audio processors and / or digital signal processors) that execute program code stored in memory (not shown) configured to perform one or more processes or operations described herein. Therefore, in embodiments, one or more components of the audio system 300 may include one or more processors, storage devices, computing devices, and / or other hardware components not shown in the figures.

[0089] All or part of the process described in this article can be derived from... Figure 9 The audio system 300 may be executed by one or more processing devices or processors (e.g., analog-to-digital converters, encryption chips, etc.) internally or externally. Additionally, one or more other types of components (e.g., memory, input and / or output devices, transmitters, receivers, buffers, drivers, discrete components, logic circuits, etc.) may also be used in conjunction with processors and / or other processing components to perform any, some, or all of the steps of any of the methods or processes described herein. For example, in some embodiments, each method described herein may be executed by a processor that runs software stored in memory. The software may include, for example, program code or computer program modules containing software instructions executable by a processor. In some embodiments, the program code may be a computer program stored on a non-transitory computer-readable medium that may be executed by a processor of the associated device.

[0090] Any processor described herein may include general-purpose processors (e.g., microprocessors) and / or special-purpose processors (e.g., audio processors, digital signal processors, etc.). In some examples, the processor described herein may be any suitable processing device or group of processing devices, such as, but not limited to, microprocessors, microcontroller-based platforms, integrated circuits, one or more field-programmable gate arrays (FPGAs) and / or one or more application-specific integrated circuits (ASICs).

[0091] Any memory or storage device described herein can be volatile memory (e.g., RAM, including non-volatile RAM, magnetic RAM, ferroelectric RAM, etc.), non-volatile memory (e.g., disk storage, flash memory, EPROM, EEPROM, memristor-based non-volatile solid-state memory, etc.), non-replaceable memory (e.g., EPROM), read-only memory, and / or high-capacity storage devices (e.g., hard disk drives, solid-state drives, etc.). In some examples, the memory described herein includes multiple types of memory, particularly volatile and non-volatile memory.

[0092] Furthermore, any memory described herein can be a computer-readable medium on which one or more sets of instructions can be embedded. During execution of the instructions, the instructions can be wholly or at least partially deployed in any one or more of the memory, the computer-readable medium, and / or in one or more processors. In some embodiments, the memory described herein may include one or more data storage devices configured to provide persistent storage for data that needs to be stored and accessed by an end user. In this case, the data storage device may store the data in flash memory or other storage devices. In some embodiments, the data storage device may be implemented using, for example, an SQLite database, UnQLite, BerkeleyDB, BangDB, etc.

[0093] Any computing device described herein can be any general-purpose computing device including at least one processor and one storage device. In some embodiments, the computing device may be a stand-alone computing device included in audio system 300, or it may be deployed in another component of audio system 300, such as microphone 302, beamformer 304, or output generation unit 306. In such embodiments, the computing device may be physically located and / or dedicated to a given environment or room (e.g., the same environment where microphone 302 is located). In other embodiments, the computing device may not be physically located near microphone 302, but may be deployed in an external network (e.g., a cloud computing network), or may otherwise be distributed in a cloud-based environment. Furthermore, in some embodiments, the computing device may be part of a network, implemented in a firmware or entirely software-based manner, that can be accessed or otherwise connected to by another device, including other computing devices (such as, for example, desktops, laptops, mobile devices, tablets, smart devices, etc.). Therefore, the term "computing device" should be understood to include distributed systems and devices (such as cloud-based systems and devices), as well as software, firmware, and other components configured to perform one or more of the functions described herein. Furthermore, one or more functions of a computing device can be physically remote and can be coupled communicatively to the computing device.

[0094] In some embodiments, any computing device described herein may include one or more components configured to support teleconferencing, meetings, classrooms, or other events, and / or process associated audio signals to improve the audio quality of the event. For example, in various embodiments, any computing device described herein may include a digital signal processor (“DSP”) configured to process audio signals received from various microphones or other audio sources using, for example, automatic mixing, matrix mixing, delay, compressor, parametric equalizer (“PEQ”) functions, acoustic echo cancellation, etc. In other embodiments, the DSP may be a standalone device operatively coupled to or connected to a computing device using a wired or wireless connection. An exemplary embodiment of a DSP (when implemented in hardware) is SHURE’s P300 IntelliMix audio conferencing processor, whose user manual is incorporated herein by reference in its entirety. As further explained in the P300 manual, this audio conferencing processor incorporates algorithms optimized for audio / video conferencing applications and is designed to deliver a high-quality audio experience, including eight-channel acoustic echo cancellation, noise reduction, and automatic gain control. Another typical embodiment of a DSP (when implemented in software) is SHURE's IntelliMix Room, whose user guide is incorporated herein by reference in its entirety. As further explained in the IntelliMix Room user guide, this DSP software is configured to optimize the performance of networked microphones in conjunction with audio and video conferencing software and is designed to run on the same computer as the conferencing software. In other embodiments, it will be understood that other types of audio processors, digital signal processors, and / or DSP software components may be used to perform one or more of the audio processing techniques described herein.

[0095] In addition, any computing device described herein may also include various other software modules or applications (not shown) configured to facilitate and / or control meeting activities, such as internal or proprietary meeting software and / or third-party meeting software (e.g., Microsoft Skype, Microsoft Teams, Bluejeans, Cisco WebEx, GoToMeeting, Zoom, Join.me, etc.). Such software applications may be stored in the memory of the computing device and / or may be stored on a remote server (e.g., locally or as part of a cloud computing network) and accessed by the computing device via a network connection. Some software applications may be configured as distributed cloud software, where one or more portions of the application are deployed in the computing device, while one or more other portions are deployed in a cloud computing network. One or more software applications may be deployed in an external network, such as a cloud computing network. In some embodiments, one or more software applications may be accessed through a web portal architecture or provided as Software as a Service (SaaS).

[0096] Typically, computer program products according to embodiments described herein include computer-usable storage media (e.g., standard random access memory (RAM), optical disc, universal serial bus (USB) drive, etc.) in which computer-readable program code is embedded, wherein the computer-readable program code is adapted to be executed by a processor (e.g., to work with an operating system) to implement the methods described herein. In this regard, the program code can be implemented in any desired language and can be implemented as machine code, assembly code, bytecode, interpreted source code, etc. (e.g., via C, C++, Java, ActionScript, Python, Objective-C, JavaScript, CSS, XML, and / or others). In some embodiments, the program code may be a computer program stored on a non-transitory computer-readable medium that can be executed by a processor of an associated device.

[0097] The terms "non-transitory computer-readable medium" and "computer-readable medium" include single or multiple media, such as centralized or distributed databases, and / or associated caches and servers storing one or more sets of instructions. Furthermore, the terms "non-transitory computer-readable medium" and "computer-readable medium" include any tangible medium capable of storing, encoding, or carrying a set of instructions for execution by a processor, or causing a system to perform one or more methods or operations disclosed herein. As used herein, the term "computer-readable medium" is explicitly defined to include any type of computer-readable storage device and / or storage disk, but excludes propagating signals.

[0098] Any flow description or block in the figure should be understood as representing a module, program segment, or code section comprising one or more executable instructions for implementing a specific logical function or step in the flow, and alternative implementations are also included within the scope of the embodiments described herein, wherein functions may be performed in a different order than shown or described, including substantially simultaneously or in reverse order, depending on the functions involved, as understood by those skilled in the art.

[0099] It should be noted that in the specification and drawings, identical or substantially similar elements may be labeled with the same reference numerals. However, sometimes these elements may be labeled with different numerals, for example, where such labeling facilitates a clearer description. Furthermore, system components may be arranged in various ways known in the art. Additionally, the drawings described herein are not necessarily drawn to scale, and in some cases, the scale may be exaggerated to more clearly describe certain features and / or related elements may be omitted to emphasize and clearly illustrate the novel features described herein. Such labeling and drawing practices do not necessarily imply any underlying substantial purpose. The above description should be considered as a whole and interpreted in accordance with the principles taught herein and understandable to those skilled in the art.

[0100] In this disclosure, the use of disjunctive conjunctions should be understood to include conjunctive conjunctions. The use of definite or indefinite articles is not intended to indicate cardinality. Specifically, references to "the" object or "one" object are also intended to indicate one of a plurality of such objects.

[0101] This disclosure describes, illustrates, and exemplifies one or more specific embodiments of the invention based on its principles. This disclosure is intended to explain how various embodiments can be designed and used according to the technology, and not to limit its true, intended, and fair scope and spirit. That is, the foregoing description is not intended to be exhaustive or limited to the precise forms disclosed herein, but rather to explain and teach the principles of the invention in a way that enables those skilled in the art to understand these principles and apply them to practice not only the embodiments described herein, but also other embodiments that may conceive based on these principles. The embodiments provided herein were chosen and described to best illustrate the principles of the technology and its practical application, and to enable those skilled in the art to use the technology in various embodiments and make various modifications according to the intended particular use. All such modifications and variations are within the scope of the embodiments defined in the appended claims, may be modified during the pending period of this patent application, and are equivalent to their equivalents when interpreted to the fullest extent they are fairly, legally, and justly enjoyed.

Claims

1. An array microphone, comprising: A plurality of microphone boards, arranged in a linear pattern along a first axis and comprising a plurality of microphone elements configured to cover a plurality of frequency bands, each microphone board comprising: A first linear array comprising a first microphone element of a plurality of microphone elements and one or more second microphone elements of the plurality of microphone elements, the first microphone element being located on a first axis, and the one or more second microphone elements being located on a second axis orthogonal to the first axis; and The second linear array includes the first microphone element and one or more third microphone elements among the plurality of microphone elements, the one or more third microphone elements being located on a third axis orthogonal to the first axis and the second axis.

2. The array microphone of claim 1, wherein the linear mode is configured to place the microphone board in a harmonic nesting configuration to cover the plurality of frequency bands.

3. The array microphone of claim 1, wherein the microphone boards are arranged substantially parallel to each other to form the linear pattern.

4. The array microphone of claim 1, wherein the linear mode is configured such that the plurality of microphone boards include a central microphone board, a first group of microphone boards arranged in a first mode on one side of the central microphone board, and a second group of microphone boards arranged in a second mode on the opposite side of the central microphone board, the second mode being a mirror image of the first mode.

5. The array microphone of claim 1, wherein the distance between adjacent microphone plates along the first axis is configured based on the linear aperture size of the array microphone.

6. The array microphone of claim 1, wherein the distance between adjacent microphone plates along the first axis is configured based on frequency values ​​included in the plurality of frequency bands.

7. The array microphone of claim 1, wherein for each microphone board, the second linear array is a mirror image of the first linear array.

8. The array microphone of claim 1, wherein on each microphone board, the distance between the first microphone element along the second axis and each of the one or more second microphone elements is configured based on the respective octaves of the plurality of frequency bands, and the distance between the first microphone element along the third axis and each of the one or more third microphone elements is configured based on the same octave.

9. The array microphone of claim 1, wherein the plurality of microphone elements are configured to form a first subarray for covering a first octave of the plurality of frequency bands and a second subarray for covering a second octave of the plurality of frequency bands across the plurality of microphone plates, the first subarray being nested within the second subarray.

10. The array microphone of claim 9, wherein the first microphone elements in the first subarray are spaced apart by a first distance along the first axis, and the first microphone elements in the second subarray are spaced apart by a second distance along the first axis, the second distance being twice the first distance, such that the first subarray and the second subarray are harmonicly nested.

11. The array microphone of claim 1, wherein each microphone board is a printed circuit board configured to form a triangular shape.

12. The array microphone of claim 1, further comprising a housing configured to encapsulate the plurality of microphone boards.

13. The array microphone of claim 1, wherein each of the plurality of microphone elements is a microelectromechanical system (MEMS) microphone.

14. An array microphone, comprising: A plurality of microphone boards arranged in a first linear pattern along a first axis of the array microphones, the plurality of microphone boards including a plurality of microphone elements configured to cover a plurality of frequency bands, each microphone board including: The first microphone element located on the first axis among the plurality of microphone elements; One or more second microphone elements located on a second axis of the microphone board, wherein the second axis is orthogonal to the first axis; and One or more third microphone elements are located on a third axis of the microphone board, wherein the third axis is orthogonal to the first axis and the second axis. The first microphone element of the plurality of microphone boards is configured to form the first linear pattern along the first axis, and For each microphone board, the first microphone element and the one or more second microphone elements are configured to form a second linear pattern along the second axis of the corresponding microphone board, and the first microphone element and the one or more third microphone elements are configured to form the second linear pattern along the third axis of the corresponding microphone board.

15. The array microphone of claim 14, wherein the first linear mode is configured to place the microphone board in a harmonic nesting configuration to cover the plurality of frequency bands.

16. A microphone system comprising: An array microphone includes multiple microphone elements arranged on multiple microphone boards, the array microphone being configured to provide audio coverage for multiple frequency bands; as well as One or more audio processors, which are in communication with the array microphones and include one or more beamformers, the one or more audio processors being configured to use the one or more beamformers: The audio pickup lobe of the array microphone is directed towards the audio source detected at the first point; and An audio output is generated based on the audio signal generated by the audio source and captured using the audio pickup lobe. The one or more beamformers are configured to direct the audio pickup lobe to any one of a plurality of points located on a sphere surrounding the center of the array microphone, the plurality of points including the first point.

17. The microphone system of claim 16, wherein the plurality of points are located at different azimuth and elevation angles around the sphere.

18. The microphone system of claim 16, wherein the plurality of points cover a solid angle of four times π spherical degrees.

19. The microphone of claim 16, wherein the audio pickup lobe includes the highest sensitivity pointing for the array microphone.

20. The microphone system of claim 16, wherein the plurality of microphone boards are arranged in a first linear pattern along a first axis, and each microphone board comprises: A first linear array comprising a first subgroup of the plurality of microphone elements, the first subgroup being configured to form a second linear pattern along a second axis of a corresponding microphone board; and A second linear array comprising a second subgroup of the plurality of microphone elements, the second subgroup being configured to form a mirror image of the first linear array along a third axis of a corresponding microphone board. The second axis is orthogonal to the first axis, and the third axis is orthogonal to both the first and second axes.

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