Microphone array, microphone device, pickup method and audio system

Abstract

The invention discloses a microphone array, microphone equipment, a pickup method and an audio system, and belongs to the technical field of acoustics, the microphone array comprises a bearing plate and a microphone assembly, the microphone assembly is arranged on the bearing plate, and the microphone assembly comprises a plurality of first microphones and at least one second microphone; wherein the plurality of first microphones are arranged around the at least one second microphone, and the plurality of first microphones are arranged in a spiral array structure according to a preset spiral line track.

Description

Technical Field

[0001] This application relates to the field of acoustic technology, and in particular to a microphone array, microphone device, sound pickup method, and audio system. Background Technology

[0002] In microphone equipment, multiple microphone units are usually arranged in a circular array, ring, rectangular array, linear array, or multiple circles arranged outward in a radial pattern (so that each microphone unit has the same phase angle).

[0003] However, the above uniform arrangement method has a common defect: poor positioning accuracy of near-field sound sources, and problems such as main beam collapse and side lobe protrusion are prone to occur during signal processing, which ultimately affect the sound pickup directivity and the accuracy of sound source positioning. Summary of the Invention

[0004] This application provides a microphone array, microphone device, sound pickup method, and audio system to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a microphone array is provided, comprising: a microphone array including: a carrier plate; a microphone assembly disposed on the carrier plate, the microphone assembly including a plurality of first microphones and at least one second microphone; In this configuration, a plurality of first microphones are arranged around at least one second microphone, and the plurality of first microphones are arranged in a spiral array structure according to a predetermined spiral trajectory.

[0006] In one possible design, the spiral trajectory may be a single-arm spiral, the spiral rotating in either a clockwise or counterclockwise direction; and / or, at least one of the second microphones may be located at the geometric center of the spiral array structure.

[0007] For example, the single-arm spiral can be planar or non-planar. For instance, if the carrier plate is planar, the microphones mounted on it can be arranged along a planar spiral. Alternatively, if the carrier plate is non-planar (e.g., configured with corresponding uneven areas), the microphones mounted on it can be arranged along a non-planar spiral.

[0008] In one possible design, along the rotation direction of the single-arm helix, a plurality of the first microphones are arranged at angular intervals with a predetermined polar angle difference.

[0009] Thus, compared to traditional circular or linear arrays that sample at specific angles, resulting in sparse sampling, the fixed polar angle interval arrangement of this embodiment allows the microphones to form a uniform angular sampling grid in planar space, avoiding sampling gaps in local areas. This ensures that multiple first microphones are evenly distributed in space, maintaining consistent sensitivity to sound from any direction, making it particularly suitable for scenarios requiring omnidirectional sound pickup, such as meeting recording and ambient sound monitoring.

[0010] In one possible design, along the rotation direction of the single-arm helix, there is a first arc distance between two adjacent first microphones, and the helical array structure includes multiple helical segments, each helical segment being the trajectory segment obtained by each revolution of the single-arm helix, wherein: Along the radial direction of the spiral array structure, the first arc distance in at least one spiral segment closer to the inner side of the second microphone is L1, and the first arc distance in at least one spiral segment farther from the second microphone is L2. L1 and L2 satisfy the relationship: L1 < L2. That is, the microphones in the inner spiral segment are densely distributed (small arc distance), and the microphones in the outer spiral segment are sparsely distributed (large arc distance).

[0011] Considering acoustic characteristics, low-frequency signals have longer wavelengths, requiring a larger microphone spacing to form an effective phase difference. In this embodiment, the arc distance between microphones in the outer spiral segment is larger, which can meet the directionality requirements of low-frequency signals. Conversely, high-frequency sound waves have shorter wavelengths. In this embodiment, the microphone array with a smaller arc distance in the inner spiral segment can avoid aliasing of high-frequency signals and effectively ensure the directional resolution of high-frequency signals.

[0012] In one possible design, the first arc distance gradually increases along the rotation direction from the inner circle to the outer circle of the single-arm helix.

[0013] In one possible design, a first spacing is provided between two adjacent spiral segments along the radial direction of the spiral array structure to form at least two first spacings, wherein the at least two first spacings have different dimensions.

[0014] In one possible design, the at least two first spacings gradually decrease along the radial radiation direction of the spiral array structure. This method, while maintaining the "dense inside, sparse outside" layout of the microphones in the spiral array, maximizes the number of microphones on the outer layer of the spiral array by setting a smaller spacing between the outer spiral segments. Smaller spacing between the outer spiral segments increases the number of outer microphones without breaking the "dense inside, sparse outside" logic; more outer microphones can balance the high-frequency beam energy distribution, reduce sidelobe protrusion problems that easily occur in high-frequency signal transmission, enhance the sampling coverage of low-frequency signals, improve low-frequency white noise gain and directivity, and ultimately achieve excellent beam performance across the entire frequency range.

[0015] In one possible design, the spiral array structure includes an inner spiral segment, a middle spiral segment, and an outer spiral segment along the radial direction, wherein the inner spiral segment, the middle spiral segment, and the outer spiral segment each include at least one spiral segment; The first spacing between two adjacent spiral segments in the inner spiral segment is smaller than the first spacing between two adjacent spiral segments in the middle spiral segment, and the first spacing between two adjacent spiral segments in the middle spiral segment is larger than the first spacing between two adjacent spiral segments in the outer spiral segment.

[0016] This method, while maintaining the "dense inside, sparse outside" layout of the microphones in the spiral array, concentrates the small-sized first spacing on the side closer to the second microphone and the side farther away from the second microphone. This further concentrates the spiral array in the central region while also increasing the number of microphones in the outer layer. Simultaneously, it enhances the high-frequency microphone pickup effect while improving the sampling coverage of low-frequency signals, ultimately achieving excellent beamforming performance across the entire frequency range.

[0017] In one possible design, along the radial direction of the spiral array structure, the number of first microphones located on multiple spiral segments with a radius less than or equal to a predetermined value is n1, and the number of first microphones located on multiple spiral segments with a radius greater than the predetermined value is n2, where n1 and n2 satisfy the relationship: n1≥n2.

[0018] In other words, in a spiral array, the number of microphones on the outer layer is less than that on the inner layer. In this spiral array layout, the inner layer microphones use a smaller arc-shaped spacing design, achieving a higher spatial sampling density even if the total number of microphones is not significantly greater than that of the outer layer. The outer layer microphones, on the other hand, can have a larger arc-shaped spacing, optimizing the overall array size and cost while ensuring low-frequency signal coverage. This non-uniform distribution of "dense inner layer, sparse outer layer" does not rely on the proportion of microphones, but rather on precisely controlling the spatial spacing between adjacent microphones to adapt to different frequency bands. This satisfies the characteristics of high-frequency signals—"short wavelength, requiring high-frequency sampling rate matching with small spacing"—effectively reducing the risk of high-frequency signal aliasing, while ensuring the spatial coverage integrity of low-frequency signals through reasonable spacing in the outer layer, simultaneously considering the uniformity and practicality of the array layout.

[0019] The aliasing threshold is positively correlated with the sampling density. In this embodiment, the high-density sampling of the inner layer can raise the aliasing threshold to over 10kHz, covering the full high-frequency range of human speech.

[0020] For example, the proportion of the outer microphone in the helical array ranges from 15% to 50%.

[0021] For example, the number of outer microphones is 20-70. Alternatively, the number of outer microphones could be 19-64.

[0022] In one possible design, the sum of the number of the first microphones and the number of the second microphones is M, where M satisfies the relationship: M ≤ 201; and / or, The number of the first microphones is N, and N satisfies the relationship: N≤200.

[0023] This method considers the relationship between white noise gain and the number of microphones: "initially, the gain increases logarithmically with the number of microphones, and then the growth slows down after the number exceeds a threshold." It then sets a lower limit for the number of microphones based on the sound pickup performance requirements, and incorporates a hardware cost model to calculate the cost-performance ratio for different numbers of microphones. This eliminates options that do not meet the performance requirements or have redundant costs, and finally selects the number of microphones that can meet the sound pickup performance requirements while controlling the hardware cost, thereby balancing sound pickup performance and cost.

[0024] In a second aspect, a microphone array is provided, comprising: a carrier plate; a microphone assembly disposed on the carrier plate, the microphone assembly including a plurality of first microphones; the plurality of first microphones being arranged in a spiral array structure according to a predetermined spiral trajectory.

[0025] In one possible design, the type of the helical trajectory includes a single-arm helical, wherein the rotation direction of the single-arm helical is either clockwise or counterclockwise.

[0026] In one possible design, along the rotation direction of the single-arm helix, a plurality of the first microphones are arranged at angular intervals with a predetermined polar angle difference.

[0027] In one possible design, along the rotation direction of the single-arm helix, there is a first arc distance between two adjacent first microphones, and the helical array structure includes multiple helical segments, each helical segment being the trajectory segment obtained by each revolution of the single-arm helix, wherein: Along the radial direction of the spiral array structure, the first arc distance in at least one spiral segment on the inner side near the geometric center of the spiral array structure is L1, and the first arc distance in at least one spiral segment on the outer side away from the geometric center of the spiral array structure is L2. L1 and L2 satisfy the relationship: L1 < L2.

[0028] In one possible design, the first arc distance gradually increases along the rotation direction from the inner circle to the outer circle of the single-arm helix.

[0029] In one possible design, along the radial direction of the spiral array structure, there is a first spacing between two adjacent spiral segments to form at least two first spacings, wherein: Along the radial direction of the spiral array structure, the first spacing on the side of the spiral array structure closer to the geometric center is greater than the first spacing on the side farther from the geometric center.

[0030] In one possible design, the first spacing gradually decreases along the radial direction of the spiral array structure.

[0031] In one possible design, along the radial direction of the spiral array structure, the number of first microphones located on multiple spiral segments with a radius less than or equal to a predetermined value is n1, and the number of first microphones located on multiple spiral segments with a radius greater than the predetermined value is n2, where n1 and n2 satisfy the relationship: n1≥n2.

[0032] In one possible design, the number of the first microphones is N, where N satisfies the relationship: N≤200.

[0033] Thirdly, a microphone array is provided, comprising: a carrier plate; a microphone assembly disposed on the carrier plate, the microphone assembly including a plurality of microphones; the plurality of microphones being arranged in a predetermined concentric circle. Wherein, in the concentric circles, the arc distance between microphones arranged on the inner circle is smaller than the arc distance between microphones arranged on the outer circle.

[0034] Optionally, the spacing between two adjacent inner circles is greater than the spacing between two adjacent outer circles. In other words, the spacing between the circles gradually decreases along the radial direction of the concentric circle array structure.

[0035] Alternatively, along the radial radiation direction of the concentric circle array, the spacing between the inner circles is smaller than the first spacing between the middle circles, and the first spacing between the middle circles is larger than the first spacing between the outer circles. In other words, along the radial radiation direction of the concentric circle array structure, from the inner layer to the outer layer, it roughly presents a structure of inner density-middle sparseness-outer density.

[0036] The inner circle is the circle closest to the center of the concentric circles, and the outer circle is the circle furthest from the center of the concentric circles.

[0037] This ensures a smaller arc distance between the inner microphones (responsible for high frequencies), thereby increasing the sampling density at high frequencies and facilitating high-frequency sampling. Furthermore, the small spacing between the outer circles allows for a maximum increase in the number of outer microphones, which helps reduce high-frequency sidelobe protrusions in the beam and improves low-frequency white noise gain and directivity.

[0038] For example, the radius difference between circles from the inside out can be set to decrease. For instance, the average radius difference of all circles in the inner microphone coil group responsible for high frequencies is greater than the average radius difference of all circles in the outer microphone coil group responsible for low frequencies.

[0039] Fourthly, a microphone device is provided, comprising a microphone array as described in any of the preceding aspects. Optionally, the microphone device may further include a processor electrically connected to the microphone components in the microphone array. The processor can be used to control the microphone device to implement one or more of the sound pickup methods of this application.

[0040] Fifthly, a sound pickup method is provided, the sound pickup method being implemented using the microphone device described in the fourth aspect, the microphone device including a microphone array, the microphone array including a plurality of first microphones arranged in a spiral array structure, the method including the following steps: Phase compensation processing is performed on the acoustic signals picked up by multiple first microphones to synthesize a directional beam pointing towards the target direction for directional sound pickup.

[0041] In this way, a directional beam that matches the current scene can be synthesized to improve the performance of directional sound pickup.

[0042] In one possible design, the microphone array further includes a second microphone, the sum of the number of the first microphones and the number of the second microphones is M, the number of the first microphones located on a multi-turn spiral segment with a radius greater than a predetermined value is n2, and both the first microphones and the second microphones include full-range microphones. The method further includes: Receive audio signals collected by M of the first microphone and the second microphone; The first microphones process the audio signal with a frequency lower than a predetermined frequency using n2 of the first microphones and then output the first pickup signal. By using M of the first microphones and the second microphones, the audio signal with a frequency greater than the predetermined frequency is processed and a second pickup signal is output; and The first and second pickup signals are combined to output the third pickup signal.

[0043] In other words, the microphone device uses n2 outer microphones in a spiral array to process low-frequency signals in order to obtain better sound pickup.

[0044] Furthermore, the microphone device's processor processes the mid-to-high frequency signals picked up by all M microphones, enabling the formation of beams with relatively consistent shapes (such as width) to better pick up mid-to-high frequency signals.

[0045] In one possible design, the step of processing the audio signal with a frequency lower than a predetermined frequency by the n2 first microphones includes: A super-pointing algorithm is used to perform beamforming processing on the audio signal with a frequency lower than the predetermined frequency to output the first pickup signal; and / or, The step of processing the audio signal with a frequency greater than the predetermined frequency using M of the first microphones and the second microphones includes: A constant beamforming algorithm is used to beamform the audio signal with a frequency greater than the predetermined frequency in order to output the second pickup signal.

[0046] This method allows the microphone device to employ a hyper-directional algorithm. When the diagonal loading factor is appropriate, it can suppress low-frequency signal noise amplification while avoiding excessive directional shift, thus achieving a balance between white noise gain and directional factor. Furthermore, combined with the "dense on the outside, sparse on the inside" layout of the spiral array, the outer microphone can more fully capture the spatial phase information of the low-frequency signal, reducing signal acquisition gaps. This facilitates obtaining a better directional factor in the low-frequency signal range and achieving the largest possible white noise gain, thereby improving the anti-reverberation and noise reduction capabilities of the low-frequency signal. This ensures that low-frequency signals (such as human voices) have good clarity and fidelity in complex scenarios.

[0047] Furthermore, by using convex optimization of the constant beam algorithm, the beamwidth of different frequency bands (mainly mid-to-high frequencies) is controlled, ensuring that the beamwidth across the entire frequency band reaches the target constant width. This results in better robustness in sound pickup.

[0048] Sixthly, an audio system is provided, including a microphone device as described in any of the preceding aspects. Optionally, the audio system may further include an audio processing device, with the microphone device electrically connected to the audio processing device. Exemplarily, the audio processing device is an audio processing host. The audio processing device can further process the audio signal from the microphone device to further improve the signal processing effect.

[0049] In a seventh aspect, the present application provides a computer-readable storage medium including computer instructions that, when executed on a device, cause the device to perform the method in any possible design of any of the above aspects.

[0050] Eighthly, the present application provides a computer program product that, when run on a device, causes the device to execute the method in any possible design of any of the above aspects.

[0051] Ninthly, this application provides a circuit system including a processing circuit configured to perform the methods in any possible design of any of the above aspects. The processing circuit can be implemented as a corresponding circuit component, such as one or more processors. Alternatively, it can be implemented as a processor and a memory. Yet another example is a processor and a transceiver.

[0052] In a tenth aspect, this application provides a chip system including at least one processor and at least one interface circuit, wherein the at least one interface circuit is used to perform transceiver functions and send instructions to the at least one processor, and when the at least one processor executes instructions, the at least one processor performs the method described in the first aspect and any of the designs therein.

[0053] Eleventhly, this application provides an audio device including a functional module, unit, or means for performing the methods in any possible design of any of the above aspects of this application. The module may be implemented by software or hardware, or by a combination of software and hardware. The inclusion of a processing unit and a communication unit is not limited.

[0054] On the twelfth page, the present application provides an audio device, including: a processor configured to perform the method of any of the above-described aspects.

[0055] Optionally, the device further includes the memory and / or a communication interface. The communication interface is coupled to the processor and is used for inputting and / or outputting information.

[0056] The memory is used to store computer programs, and the processor is configured to perform a method of any of the above-described designs, which can be implemented as: a method for executing a computer program stored in the memory to perform any of the above-described designs.

[0057] Alternatively, the processor can also be a hardware-implemented circuit, such as an artificial intelligence (AI) processor, to improve operating speed. This application does not limit the specific implementation of the processor.

[0058] Optionally, the audio device can be a complete device or a module within a device, such as a chip.

[0059] The microphone array of this application includes a carrier plate and a microphone assembly disposed on the carrier plate. Multiple first microphones in the microphone assembly are arranged around at least one second microphone, and the multiple first microphones are arranged in a helical array structure according to a predetermined helical trajectory. Because the microphones arranged in a helical array structure have a variable spacing, they can be matched with different sound signals. Specifically, since the wavelengths of sound signals of different frequencies differ, low-frequency signals have longer wavelengths and require a larger microphone spacing to form an effective phase difference to ensure directionality, while high-frequency signals have shorter wavelengths and require a smaller microphone spacing to avoid signal aliasing and ensure directional resolution. The non-fixed spacing characteristic of the helical array can accurately match the above-mentioned requirements of different frequency signals, thereby achieving aliasing-free sampling of sound over a wide frequency range. This adaptive sampling can reduce phase deviation caused by spacing and frequency mismatch in subsequent signal processing, thereby minimizing problems such as main beam collapse and side lobe protrusion, so as not to affect the pickup directivity and sound source localization accuracy.

[0060] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0062] Figure 1 This is a schematic diagram of the overall structure of the microphone array provided in an exemplary embodiment of this disclosure; Figure 2 This is a graph showing the relationship between the number of microphones and white noise gain provided in an exemplary embodiment of this disclosure; Figure 3 This is a schematic flowchart of the sound pickup method provided in an exemplary embodiment of this disclosure; Figure 4This is a schematic diagram of a scenario for beam shape adjustment (narrow beam) provided in an exemplary embodiment of this disclosure; Figure 5A and Figure 5B This is a schematic diagram of a scenario for beam shape adjustment (wide beam) provided in an exemplary embodiment of this disclosure; Figure 6 , Figure 7 This is a schematic flowchart of the sound pickup method provided in an exemplary embodiment of this disclosure; Figure 8 This is a schematic diagram of various frequency band sound pickup methods provided in the exemplary embodiments of this disclosure; Figure 9 This is a schematic diagram of a multi-armed spiral trajectory provided in an exemplary embodiment of this disclosure.

[0063] Explanation of reference numerals in the attached figures: 10. Carrier plate; 11. Microphone assembly; 110. First microphone; 111. Second microphone. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0065] As mentioned earlier, current microphone arrays often suffer from issues with sound pickup directivity and sound source localization accuracy. For example, linear arrays exhibit sparse sampling at certain angles. Rectangular arrays occupy a large amount of space. Circular arrays suffer from limited spacing between edge units, insufficient sampling uniformity, and sparse sampling. Ring-shaped multi-ring ray arrays have sampling uniformity issues, exhibiting radial sparse sampling and generating side lobes, thus affecting the picked-up sound quality.

[0066] To address the current problems of poor microphone directivity and inaccurate sound source localization in microphone devices, a microphone structural design is proposed to improve both microphone directivity and sound source localization accuracy.

[0067] In the process of systematically analyzing the acoustic performance of microphone arrays, the invention team identified a long-standing but unresolved technical contradiction: although the industry generally uses regular geometric shapes such as circles, rings, rectangles or lines as the arrangement of microphone arrays, these uniform arrangement structures have inherent acoustic limitations at the physical level.

[0068] Specifically, whether it's the limited spacing of edge elements in a circular array, the sparse sampling of a linear array at a specific angle, or the low space utilization of a rectangular array, the essence can be attributed to the mismatch between fixed-spacing sampling and the broadband characteristics of sound waves. This mismatch leads to systematic deviations in near-field sound source localization and causes inherent problems such as main beam collapse and sidelobe energy leakage during beamforming. It is noteworthy that because these defects exist uniformly in various regular arrays, they are often perceived as "inherent technical limitations," failing to prompt in-depth investigation into the fundamental issues.

[0069] Further analysis revealed that the performance bottleneck of uniform arrays stems from the mismatch between their spatial sampling method and the physical characteristics of sound waves: high-frequency sound waves require dense sampling to avoid aliasing, while low-frequency sound waves require a larger aperture to ensure resolution. This contradiction, in traditional design paradigms, is simply translated into a trade-off between high-frequency and low-frequency performance, rather than being addressed systematically at the level of acoustic sampling theory.

[0070] Based on this, the embodiments of this application provide a microphone structure design to improve the directivity of sound pickup and the accuracy of sound source localization. Focusing on "how to overcome the acoustic limitations of uniform sampling arrays", a microphone arrangement that can adaptively match the characteristics of wideband acoustic waves is established, which solves the problem of improving the system accuracy of directivity and localization from a physical level.

[0071] Reference Figure 1 The present disclosure provides an exemplary structure for a microphone array, which may include a carrier plate 10 and a microphone assembly 11. The microphone assembly 11 is disposed on the carrier plate 10.

[0072] The microphone assembly includes a plurality of first microphones 110 and at least one second microphone 111. The plurality of first microphones are arranged around the at least one second microphone 111, and the plurality of first microphones 110 are arranged in a spiral array structure according to a predetermined spiral trajectory.

[0073] Figure 1 An example of a spiral trajectory is shown, with the center of the spiral trajectory as the origin and the x-axis as the starting point. m11 is the first microphone in the spiral array structure, m12 is the second microphone in the spiral array structure, m13 is the third microphone in the spiral array structure, and so on. The microphones are arranged in a spiral array structure according to the spiral trajectory shown in the figure.

[0074] Still Figure 1 As the spiral unfolds, the polar angle corresponding to the location of each microphone gradually increases. For example, Figure 1In this case, the polar angle at the location of m3 is greater than the polar angle at the location of m2. Due to the characteristics of a spiral, the spacing between microphones arranged along a spiral trajectory is not fixed. (The sentence is incomplete and ends abruptly.) Figure 1 The arc length distance (or arc distance) between m11 and m12 is less than the arc distance between m21 and m22.

[0075] Compared to microphone arrays with fixed spacing (such as linear arrays which are prone to high-frequency aliasing, and omnidirectional arrays which suffer from insufficient low-frequency resolution), the aforementioned technical solution uses microphones arranged in a spiral array structure with variable spacing. Different spacings can match different frequency signal ranges, enabling aliasing-free sampling of a wide frequency range. This minimizes issues such as main beam collapse and sidelobe protrusion during signal processing, thus avoiding impacts on pickup directivity and sound source localization accuracy.

[0076] Furthermore, compared to the circular array where microphones are all concentrated on the same circumference, resulting in limited angular resolution, the spiral array structure of this application embodiment allows the microphones to be distributed in layers in the radial direction (which can be referred to as radial), which can simultaneously take into account sound sampling at different distances and enhance the sense of spatial layering.

[0077] Furthermore, the spiral array layout can accommodate multiple microphones in a smaller area. Compared to the same number of rectangular arrays (which occupy more space) or circular arrays (where the spacing between edge units is limited), the spiral array structure of this application embodiment can efficiently utilize space within the same size, thereby achieving a better spatial sampling density and improving the ability to distinguish sound field direction information. For example, it can achieve higher sampling density and distinguish between two relatively close sound sources.

[0078] Furthermore, the microphone array in this embodiment is arranged in an orderly spiral trajectory, with the microphone positions following a clear and fixed geometric pattern. This eliminates the need for additional coordinate calibration and position correlation analysis of the irregular microphone positions in a randomly distributed array. Simultaneously, the orderly spiral arrangement allows for predictable calculation logic for parameters such as phase difference and delay difference in the signals acquired by each microphone, avoiding redundant signal processing calculations caused by positional uncertainty in random arrays. Therefore, it minimizes the complexity of signal processing by a randomly distributed array, making signal processing more efficient.

[0079] Furthermore, due to the symmetry of the spiral, the distribution of each first microphone on the support plate in the spiral array structure of this application embodiment is uniformly symmetrical. This symmetrical layout allows the microphone installation load (such as weight and fixing stress) on the support plate to be uniformly transmitted along the spiral trajectory, avoiding structural weakness caused by load concentration in local areas. At the same time, the symmetrical array shape allows external vibrations (such as environmental vibrations and vibrations from the device itself) to be dispersed and canceled along the symmetrical spiral path during operation, reducing structural resonance caused by vibration concentration under asymmetrical layout, thereby reducing vibration and noise interference caused by uneven layout, thus improving the stability and durability of the microphone device.

[0080] In some embodiments, the type of helical trajectory includes a single-arm helix, wherein the rotation direction of the single-arm helix is ​​clockwise or counterclockwise. The above... Figure 1 A single-armed helix rotating counterclockwise is shown, but this does not constitute a limitation on single-armed helices.

[0081] In some embodiments, at least one second microphone 111 is located at the geometric center of the helical array structure. Still as Figure 1 The second microphone m0 is located at the geometric center of the spiral array structure.

[0082] In this embodiment, the second microphone 111 may also be referred to as the center microphone. The first microphone 110 may also be referred to as a spiral array microphone.

[0083] In this embodiment, on the one hand, the presence of the central microphone creates a radial positional difference with the outer microphones in the helical array. Its position at the geometric center of the helical array allows for more direct capture of vertical sound pressure changes from near-field sound sources. Simultaneously, the path difference with the surrounding first microphones provides a more accurate height-dimensional positioning reference, reducing height positioning deviations caused by radial sampling gaps when relying solely on peripheral microphones. This helps improve the accuracy and precision of near-field sound source height positioning. On the other hand, in the constant beamforming design process, the central microphone serves as a core reference point for high-frequency signal sampling. Its collected high-frequency signals complement the high-frequency signals from each of the first microphones, filling subtle gaps in the high-frequency sampling within the helical array and preventing uneven beam energy distribution due to insufficient local high-frequency sampling density. Furthermore, the signal from the central microphone balances the phase consistency of the high-frequency beam, reducing beam distortion caused by phase shifts. This helps improve the stability of beam broadening in the high-frequency range, reducing the likelihood of main beam collapse and side lobe protrusion, and improving white noise gain in the high-frequency range. Therefore, the presence of the central microphone plays a crucial role in near-field sound source localization and constant beam broadening design.

[0084] In some embodiments, multiple first microphones 110 are arranged at equal angular intervals with predetermined polar angle differences along the rotation direction of the single-arm helix. That is, along the rotation direction of the helix, the polar angle difference between any two adjacent first microphone units 110 is equal. In other words, the included angle between any two microphones, with the central microphone as the vertex, is equal. As before... Figure 1 The angle between the lines connecting m11 and m0, and m12 and m0, is denoted as θ. m11-m12 The line connecting m12 and m0, and the line connecting m13 and m0, with the included angle denoted as θ. m12-m13 θ m11-m12 With θ m12-m13 They are equal. For example, the angle between the lines connecting m20 and m0, and m21 and m0, is denoted as θ. m20-m21 The line connecting m21 and m0, and the line connecting m22 and m0, with the included angle denoted as θ. m21-m22 θ m20-m21 With θ m21-m22 equal.

[0085] Thus, compared to traditional circular or linear arrays that sample at a specific angle, resulting in sparse sampling, the fixed polar angle difference spacing arrangement in this embodiment of the application can ensure that multiple first microphones 110 are evenly distributed in space, maintaining consistent sensitivity to sound from any direction. This is especially suitable for scenarios requiring omnidirectional sound reception, such as meeting recording and environmental sound monitoring.

[0086] For example, the phase angle difference between two adjacent microphones on the spiral is 37.4°.

[0087] In some embodiments, a first arc distance exists between two adjacent first microphones 110 along the rotation direction of the single-arm helix. The helical array structure includes multiple helical segments (or multi-turn helical segments), each helical segment being the trajectory segment obtained by each rotation of the single-arm helix. Among the multiple helical segments, the helical segment closer to the center microphone and located in the innermost layer can be called the inner helical segment. The helical segment farther from the center microphone and located in the outermost layer can be called the outer helical segment.

[0088] Still Figure 1 The spiral array structure includes spiral segment 1, which starts at m11 and rotates counterclockwise for one revolution, passing through m12-m19, m20, and ending at m21. Similarly, spiral segment 2, which starts at m21 and rotates counterclockwise for one revolution, ends at m31. Spiral segment 1, compared to spiral segment 2, can be called the inner spiral segment. Spiral segment 2, compared to spiral segment 1, can be called the outer spiral segment.

[0089] It should be noted that each spiral segment may not be exactly 360 degrees. For example, as... Figure 1If, following the direction of the spiral's rotation, a line is drawn from the first microphone (m11) to the tenth microphone (m20), with the center microphone as the vertex, the total angle between the ten microphones is less than 360 degrees. Conversely, if the line is drawn from the first microphone (m11) to the eleventh microphone (m21), with the center microphone as the vertex, the total angle is greater than 360 degrees.

[0090] For example, the helical array structure comprises 13 helical segments. For example, the minimum radius of the helical segment is 0.021m and the maximum radius is 0.268m.

[0091] In some embodiments, along the radial direction of the spiral array structure, the first arc distance in at least one spiral segment near the inner side of the second microphone 111 is L1, and the first arc distance in at least one spiral segment away from the second microphone 111 is L2. L1 and L2 satisfy the relationship: L1 < L2. That is, the first arc distance in the inner spiral segment is smaller than the first arc distance in the outer spiral segment. This arc distance distribution in the embodiments of this application can be called a "dense inside, sparse outside" distribution, that is, the microphones in the inner spiral segment are densely distributed (small arc distance), and the microphones in the outer spiral segment are sparsely distributed (large arc distance).

[0092] Still Figure 1 The first arc distance between m11 and m12 is denoted as L1. The first arc distance between m21 and m22 is denoted as L2. L1 is less than L2.

[0093] Considering acoustic characteristics, low-frequency signals have longer wavelengths, requiring a larger microphone spacing to form an effective phase difference. In this embodiment, the arc distance between microphones in the outer spiral segment is larger, which satisfies the directionality requirement of low-frequency signals. Conversely, high-frequency sound waves have shorter wavelengths. In this embodiment, the microphone array with a smaller arc distance in the inner spiral segment avoids aliasing of high-frequency signals and effectively ensures the directional resolution of high-frequency signals.

[0094] The above describes the arc distance pattern along the radial direction of the helix. Next, we will describe the arc distance pattern along the rotational direction of the helix.

[0095] In some embodiments, the first arc distance gradually increases along the rotation direction from the inner circle to the outer circle of the single-arm helix. Still as Figure 1 Along the direction of rotation of the helix, the first arc distance between m11 and m12 is less than the first arc distance between m12 and m13. Similarly, the first arc distance between m20 and m21 is less than the first arc distance between m21 and m22.

[0096] In some embodiments, further adjustments can be made based on the density between each ring of microphones to enhance sound quality. As one possible implementation, a first spacing is present between adjacent spiral segments along the radial direction of the spiral array structure to form at least two first spacings. Still as Figure 1Along the radial direction of the spiral array structure, the first spacing between the first and second spiral segments is d1, and the first spacing between the second and third spiral segments is d2.

[0097] As one possible implementation, the at least two first spacing dimensions are different. That is, in the helical array, the first spacing between two adjacent helical segments is not always equal. For example, along the radial direction of the helical array, the first spacing d1 between the first and second helical segments is different from the first spacing d2 between the second and third helical segments.

[0098] As one possible implementation, along the radial radiation direction of the helical array structure, the first spacing on the side of the helical array structure closer to the second microphone 111 is greater than the first spacing on the side farther from the second microphone 111. In other words, along the radial radiation direction of the helical array structure, at least two of the first spacings gradually decrease from the inner layer to the outer layer. That is, the first spacing between the inner layer helical segments is greater than the first spacing between the outer layer helical segments. This distribution can be called an inner-sparse-outer-dense distribution, that is, the inner layer helical segments are sparsely distributed, and the outer layer helical segments are densely distributed.

[0099] Still Figure 1 Along the radial direction of the helical array structure, the distance d1 between the first and second helical segments is greater than the distance d2 between the second and third helical segments. That is, the helical segments are more sparsely distributed towards the inner layers, and more densely distributed towards the outer layers.

[0100] It should be noted that from the inner layer to the outer layer, at least two first spacings gradually decrease. This does not mean that the spacings between adjacent first spacings decrease strictly, but rather that there is an overall decreasing trend from the inner layer to the outer layer. For example, in some examples, from the inner layer to the outer layer, the first spacing of the inner multi-layer spiral segments gradually decreases, while the first spacing of the middle multi-layer spiral segments is equal. The first spacing of the outer multi-layer spiral segments gradually decreases.

[0101] Considering acoustic characteristics, a low proportion of outer microphones can cause high-frequency sidelobe protrusion in the beam. To address this issue, this embodiment limits the number of microphones on the inner spiral segments, resulting in a larger spacing between them. This ensures a "dense inner, sparse outer" microphone layout within the spiral array while minimizing the spacing between outer spiral segments, maximizing the number of microphones on the outer layer. This reduces high-frequency sidelobe protrusion and improves low-frequency white noise gain and directivity, resulting in excellent beam performance across the entire frequency range. For example, in low frequencies (below 2kHz), the following performance is achieved: white noise gain range of 6-15dB, directivity range of 0-14. In high frequencies (above 2kHz), the following performance is achieved: white noise gain range of 15-18dB, directivity range of 14-16. The full-band sidelobe suppression depth ranges from 10-40dB, with no abnormal sidelobe protrusions (e.g., degradation to 5-10dB) across the entire frequency range.

[0102] For example, the number of inner layer microphones can be limited to the number of microphones within a 0.1m radius, such as a limit of 26.

[0103] In some embodiments, to specifically enhance the high-frequency and low-frequency pickup performance of the microphone, the density of each ring of microphones near and away from the center region can be further adjusted. As one possible implementation, the spiral array structure includes an inner spiral segment, a middle spiral segment, and an outer spiral segment along the radial direction, each of which includes at least one spiral segment.

[0104] Among them, the first spacing between the inner spiral segments is smaller than the first spacing between the middle spiral segments, and the first spacing between the middle spiral segments is larger than the first spacing between the outer spiral segments.

[0105] In other words, along the radial direction of the spiral array structure, the smaller first spacing is distributed on the side closer to the second microphone (inner layer) and on the side farther from the second microphone (outer layer). In other words, along the radial direction of the spiral array structure, from the inner layer to the outer layer, the first spacing between the inner spiral segments and the first spacing between the outer spiral segments are generally smaller than the first spacing between the middle spiral segments. It should be noted that the term "inner layer" here does not only refer to the first spacing between the first and second spiral segments, but rather to the collective first spacing between spiral segments closer to the center microphone compared to the entire microphone array. Similarly, the term "outer layer spiral segment" does not only refer to the first spacing between the penultimate and penultimate spiral segments, but rather to the collective first spacing between spiral segments farther from the center microphone compared to the entire microphone array.

[0106] like Figure 2 Along the radial direction of the spiral array structure, the first spacing between the first and second spiral segments is d1, the first spacing between the penultimate and penultimate spiral segments is d2, and the first spacing between the eighth and ninth spiral segments is d3. Specifically, along the radial direction of the spiral array structure, d1 between the first and second spiral segments is smaller than d3 between the eighth and ninth spiral segments; d2 between the penultimate and penultimate spiral segments is smaller than d3 between the eighth and ninth spiral segments. That is, the overall structure exhibits a dense inner layer, a sparse middle layer, and a dense outer layer.

[0107] For example, in this embodiment of the application, the overall trend can be defined as the change in the average first spacing size of each layer. For instance, the average first spacing of the inner layer is smaller than the average first spacing of the middle layer. Or, the average first spacing of the middle layer is larger than the average first spacing of the outer layer.

[0108] In some embodiments, a smoothing approach can also be used. For example, the gradient gradually increases and then decreases from the inside out.

[0109] In some embodiments, the first spacing of each layer may be the same. For example, the first spacing of the inner layers may be the same. Alternatively, the first spacing of the middle layers may be the same. Or, the first spacing of the outer layers may be the same.

[0110] In some embodiments, the size of the first spacing of the outer layer and the first spacing of the inner layer can be: the first spacing of the outer layer is greater than the first spacing of the inner layer (referred to as outer larger than inner smaller). Alternatively, it can be inner larger than outer smaller.

[0111] In terms of acoustic performance, the smaller initial spacing between the spiral segments farther from the center microphone and the smaller initial spacing between the spiral segments closer to the center microphone are more conducive to concentrating microphone performance on capturing mid-to-high and low frequencies. In the field of video conferencing, mid-to-high frequency performance is more demanding than low-frequency performance, but too few low-frequency microphones often lead to insufficient low-frequency signal pickup and decreased sound fidelity. Specifically, this manifests as a lack of detail in the bass frequencies when participants speak, resulting in a thin and lacking richness in the voice. This is especially true for users with naturally deep voices, whose speech information is prone to detail loss, affecting auditory comfort during remote communication.

[0112] In this embodiment, different array density settings are used to improve the upper limit of beam performance (white noise gain, pointing factor, and sidelobe suppression depth, etc.) in specific frequency bands. For example, a denser inner beam and a sparser outer beam result in better beam characteristics in the high-frequency range, meaning that different degrees of beam widening can achieve better sidelobe suppression levels. Thus, by adjusting the upper limit of quality for different beamwidths, the clarity of sound pickup can be improved. For instance, the upper limit of the algorithm's optimization capability is determined by the array distribution.

[0113] Furthermore, increased robustness of beamwidth control and improved beam quality in specific frequency bands are more conducive to the application of area pickup functionality. For example, different sized areas can be matched with beams of different widths, all of which have sufficiently good beam characteristics.

[0114] The microphone layout of this application embodiment enables the microphone array to achieve "precise full-band coverage" in video conferencing scenarios: the fundamental human voice frequency in the low-frequency band (such as 200-500Hz) is fully captured; key voice information in the mid-to-high frequency band (such as 1-4kHz) is clearly picked up, ensuring voice recognition during remote communication; at the same time, the sidelobe suppression depth of the full-band can be stably maintained at a good level, and even in scenarios where multiple people are speaking and there is background noise in the environment (such as air conditioning noise, keyboard noise), interference signals can be effectively suppressed, the target voice can be focused, and the stability and anti-interference ability of the overall meeting sound quality can be improved.

[0115] Depending on the different environmental requirements, in some embodiments, the density between each ring of microphones in the microphone array can be adjusted to reduce the first gap between the helical segments of the microphones in the middle layer region, in order to meet the requirements of mid-frequency acquisition, such as the need to increase the mid-frequency audio acquisition capability.

[0116] In some embodiments, along the radial direction of the spiral array structure, the number of first microphones 110 located on multi-turn spiral segments with a radius less than or equal to a predetermined value is n1, and the number of first microphones 110 located on multi-turn spiral segments with a radius greater than the predetermined value is n2. Still as Figure 1 On the x-axis, the radius of point P1-P2 is r. The inner radius of point P1-P2 is less than r, and the outer radius of point P1-P2 is greater than r. The number n1 of the first microphone 110 inside point P1-P2 (shown as black-filled dots) is 55, and the number n2 of the first microphone 110 outside point P1-P2 (shown as white-filled dots) is 71.

[0117] The aforementioned n1 and n2 satisfy the relationship: n1 ≥ n2. That is, in the spiral array, the number of microphones in the inner layer is less than the number of microphones in the outer layer. As mentioned above, a larger number of outer layer microphones can reduce the probability of sidelobe bulging at high frequencies.

[0118] In some embodiments, the sum of the number of first microphones 110 and the number of second microphones 111 is M, where M satisfies the relationship: M≤201.

[0119] In some embodiments, the number of first microphones 110 is N, where N satisfies the relationship: N≤200.

[0120] like Figure 3The relationship between white noise gain and the number of microphones is shown, where the x-axis represents the number of microphones and the y-axis represents the white noise gain. The number of microphones is the sum of the number of the first microphone 110 and the number of the second microphone 111. Figure 3 The white noise gain exhibits a logarithmic trend with respect to the number of microphones: y = 10 * lg(x).

[0121] Depend on Figure 3 When the number of microphones (x) is 64, the number of microphones is basically proportional to the white noise gain. When x is greater than 201, the change in white noise gain becomes relatively flat as the number of microphones increases. Therefore, considering performance and cost, the number of microphones can be set between 64 and 201. For example, 201 microphones means one center microphone and 200 spiral array microphones. Another example is 127 microphones, meaning one center microphone and 126 spiral array microphones.

[0122] This application also provides a microphone device, which includes a microphone array. The microphone device of this application can be any device that needs to collect sound sources, such as miniaturized devices like smart speakers and portable recording devices, to improve the sound source collection performance of the device.

[0123] This application also provides an audio system, including a microphone device.

[0124] This application also provides a sound pickup method implemented using a microphone device, which includes a microphone array. The microphone array includes a plurality of first microphones arranged in a helical array structure. The structure of the microphone array can be found in other relevant content herein and will not be described again.

[0125] Among them, such as Figure 4 As shown, the sound pickup method includes the following steps: S101: Perform phase compensation processing on the acoustic signals picked up by multiple first microphones to synthesize a directional beam pointing towards the target direction for directional sound pickup.

[0126] As one possible implementation, the microphone device performs phase compensation processing on the acoustic signals picked up by multiple helical array microphones to synthesize a directional beam that matches the current scene, thereby improving the performance of directional sound pickup. The beamwidth can be dynamically adjusted.

[0127] For example, Figure 5A The narrow beam shown is used to focus on a specific sound source. Figure 5B The wide beam shown is used to cover multi-person conversations.

[0128] As one possible implementation, leveraging the symmetry of the spiral, the microphone device can select microphones of different radii in any target direction, such as θ, to form a sub-array. For example, based on the pickup signals from n inner microphones and m outer microphones, a directional beam can be synthesized through phase compensation to pick up sound in a specific direction.

[0129] In some embodiments, the microphone array further includes a second microphone, the sum of the number of the first microphones and the number of the second microphones is M, the number of the first microphones located on a multi-turn spiral segment with a radius greater than a predetermined value is n2, and both the first and second microphones include full-range microphones. For example... Figure 6 The methods also include: S201: Receive audio signals collected by M first microphones and second microphones.

[0130] S202. The first pickup signal is output after the audio signal with a frequency lower than the predetermined frequency is processed by n2 first microphones.

[0131] As one possible implementation, such as Figure 7 S202 can be implemented as S202a: The microphone device can use a hyper-pointing algorithm to perform beamforming processing on audio signals with frequencies lower than a predetermined frequency to output a first pickup signal. The audio signals with frequencies lower than the predetermined frequency can be referred to as low-frequency signals. That is, the microphone device uses n² outer microphones in a helical array to process the low-frequency signals.

[0132] As mentioned above, in a spiral array, the adjacent inner microphones are relatively close together. Since low-frequency signals have longer wavelengths, the close microphone spacing makes it difficult to create an effective phase difference, hindering the accurate capture of the spatial orientation information of low-frequency signals. This results in poor directivity of the inner microphones for low-frequency signals. Furthermore, the close spacing makes the low-frequency signals collected by the inner microphones more correlated, weakening their directional resolution. In other words, the inner microphones in a spiral array perform worse in the low-frequency range than the outer microphones. In contrast, the outer microphones are spaced further apart, allowing for better adaptation to the wavelength characteristics of low-frequency signals. This creates a significant phase difference, enabling accurate identification of the low-frequency sound source and reducing interference from signal correlation. Therefore, microphone devices use outer microphones to process low-frequency signals for better sound pickup.

[0133] like Figure 8 The microphone device's processor performs beamforming processing based on the low-frequency signals picked up by the microphone on the outer spiral segment (shown as white-filled dots) and a super-directional algorithm, which can form a beam with better directivity in order to better pick up low-frequency signals.

[0134] For example, the microphone device can employ a robust hyper-pointing algorithm, achieving a balance between white noise gain and pointing factor by rotating a fixed diagonal loading factor. Furthermore, combined with the "dense on the outside, sparse on the inside" layout of the spiral array, it is beneficial to obtain a better pointing factor in the low-frequency signal range and achieve the largest possible white noise gain, thereby improving the anti-reverberation and noise reduction capabilities of low-frequency signals, ensuring that low-frequency signals (such as human voices) have good clarity and fidelity in complex scenarios.

[0135] For example, the value range of the fixed diagonal loading factor is 0.001 to 1.

[0136] S203. Using M first microphones and second microphones, the audio signal with a frequency greater than a predetermined frequency is processed and the second pickup signal is output.

[0137] As one possible implementation, such as Figure 7 S203 can be implemented as S203a: The microphone device can use a constant beamforming algorithm to beamform audio signals with frequencies higher than a predetermined frequency to output a second pickup signal. In this context, audio signals with frequencies higher than the predetermined frequency can be referred to as mid-to-high frequency signals.

[0138] like Figure 8 The microphone device's processor performs beamforming processing based on the mid-to-high frequency signals picked up by all M microphones and a constant beamforming algorithm, which can form beams with relatively consistent widths to better pick up mid-to-high frequency signals.

[0139] Compared to conventional beamforming techniques, the beamwidth narrows from low to high frequencies. This uneven beamwidth results in poor sound pickup robustness, especially in complex scenarios where it is easily affected by positioning deviations. This leads to a dull and muffled tone in the mid-to-high frequency range, impacting the sound quality experience. In this embodiment, the beamwidth of different frequency bands (e.g., mainly mid-to-high frequencies) is controlled through convex optimization of the constant beam algorithm, so that the beamwidth of the entire frequency band reaches the target constant width.

[0140] This gives the sound pickup good robustness, ensuring that the main beam has the ability to achieve three-frequency equalization within a certain area. The area width is determined by the beamwidth. Three-frequency equalization refers to the relatively flat energy curves of the low, mid, and high frequencies.

[0141] On the other hand, it can significantly improve the suppression depth of side lobes and effectively suppress directional interference noise.

[0142] In general, the embodiments of this application can achieve a constant beam at mid-to-high frequencies using M microphones. This scheme has a high degree of freedom and can achieve free control of the beamwidth (20~60°) and sidelobe suppression depth (10~40dB) of the azimuth and elevation angles by reasonably controlling the balance between white noise gain and pointing factor.

[0143] S204. Combine the first and second pickup signals and output the third pickup signal.

[0144] In summary, the microphone array, microphone device, sound pickup method, and audio system obtained in this application can achieve the following technical advantages: Advantage 1: Omnidirectional and precise sound pickup, eliminating the drawbacks of angled sampling: Utilizing a spiral layout, the polar angle difference between adjacent microphones is equal along the spiral's rotation direction. This ensures uniform microphone distribution in space, effectively avoiding the sparse sampling problem of traditional circular or linear arrays at specific angles. Consequently, consistent sensitivity is maintained for both speeches from any direction during a meeting and sounds from different directions in environmental sound monitoring, achieving omnidirectional, blind-spot-free sound pickup.

[0145] Advantage 2: Excellent wideband sound processing capabilities Low-frequency performance: The outer (large radius) microphone spacing of the spiral array meets the directionality requirements for low frequencies. Furthermore, combined with robust hyperdirectional technology and a fixed diagonal loading factor, a large white noise gain is achieved while ensuring a superior low-frequency directivity factor. This effectively improves the low-frequency anti-reverberation and noise reduction capabilities, ensuring the clarity and fidelity of low-frequency vocals in complex scenarios.

[0146] High-frequency performance: The inner layer (small radius) microphones of the spiral array have a smaller spacing, which reduces high-frequency aliasing. Furthermore, combined with constant beamforming technology and the use of all M microphones for pickup, convex optimization can be used to control the beamwidth of mid and high frequencies to remain constant, solving the problem of narrowing mid and high-frequency beamwidth in conventional beamforming, and ensuring the directional resolution and sound quality stability of mid and high-frequency signals.

[0147] Advantage 3: Excellent beam performance, flexibly adaptable to various scenarios Dynamically adjustable beamwidth: Supports narrow beamwidth (e.g., 30°) focusing on specific sound sources, such as for precise pickup when a single person is speaking. It also supports switching to a wider beamwidth (e.g., 120°), such as covering multi-person conversations. In this way, the pickup needs of different scenarios can be met by dynamically switching the beamwidth.

[0148] High beam shape consistency: The scheme of this application has a sidelobe suppression ratio of ≥10dB in any direction, which is better than that of linear array, and can effectively reduce sidelobe interference and improve the purity of sound pickup.

[0149] Constant beam characteristics: By using constant beam technology, the main beam is ensured to have equal frequency response across a certain range, significantly improving sidelobe suppression depth (10-40dB) and enhancing anti-interference capabilities. Thus, even in complex scenarios, the problem of dull and muffled mid- and high-frequency tones caused by positioning deviation can be avoided.

[0150] Advantage 4: High cost-performance ratio and efficient space utilization Cost and performance balance: Based on the logarithmic relationship between white noise gain and the number of microphones (10*lg(M)), within the range of 64-201 microphones, a suitable number of microphones can be selected to ensure beam performance (white noise gain, directivity, etc.) while controlling the overall cost, thus achieving high cost performance.

[0151] The above example illustrates a single-armed helix. In other embodiments, microphones arranged along a single-armed helix can also be represented as arranged along a multi-armed helix. For example, Figure 9 Except for the central microphone at center point O, starting from the first microphone closest to the innermost layer, every 10 microphones are numbered in a round, and all microphones with the same number are connected to form a multi-armed spiral.

[0152] The above example primarily uses a central microphone, but there can be multiple central microphones. For instance, a ring of microphones can be arranged around the center.

[0153] In addition to recessed installation, microphone devices can also be installed by ceiling mounting (fixed to the ceiling) or suspended from the ceiling by a hanging wire. This application does not limit the specific installation method.

[0154] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0155] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0156] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0157] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A microphone array, characterized in that, include: Support plate; A microphone assembly disposed on the carrier plate, the microphone assembly including a plurality of first microphones and at least one second microphone; In this configuration, a plurality of first microphones are arranged around at least one second microphone, and the plurality of first microphones are arranged in a spiral array structure according to a predetermined spiral trajectory.

2. The microphone array according to claim 1, characterized in that, The type of helical trajectory includes a single-arm helical, wherein the rotation direction of the single-arm helical is clockwise or counterclockwise; and / or, At least one of the second microphones is located at the geometric center of the spiral array structure.

3. The microphone array according to claim 2, characterized in that, Along the rotation direction of the single-arm spiral, a plurality of the first microphones are arranged at angular intervals with a predetermined polar angle difference.

4. The microphone array according to claim 3, characterized in that, Along the rotation direction of the single-arm helix, there is a first arc distance between two adjacent first microphones, and the helical array structure includes multiple helical segments, each helical segment being the trajectory segment obtained by each rotation of the single-arm helix, wherein: Along the radial direction of the spiral array structure, the first arc distance in at least one spiral segment closer to the inner side of the second microphone is L1, and the first arc distance in at least one spiral segment farther from the outer side of the second microphone is L2. L1 and L2 satisfy the relationship: L1 < L2.

5. The microphone array according to claim 4, characterized in that, As the rotational direction along the single-arm helix from the inner circle to the outer circle increases, the first arc distance gradually increases.

6. The microphone array according to any one of claims 4, characterized in that, Along the radial direction of the spiral array structure, there is a first spacing between two adjacent spiral segments to form at least two first spacings, wherein the at least two first spacings have different dimensions.

7. The microphone array according to claim 6, characterized in that, Along the radial direction of the spiral array structure, the at least two first spacings gradually decrease.

8. The microphone array according to claim 6, characterized in that, The spiral array structure includes an inner spiral segment, a middle spiral segment, and an outer spiral segment along the radial direction, and each of the inner spiral segment, the middle spiral segment, and the outer spiral segment includes at least one spiral segment. The first spacing between two adjacent spiral segments in the inner spiral segment is smaller than the first spacing between two adjacent spiral segments in the middle spiral segment, and the first spacing between two adjacent spiral segments in the middle spiral segment is larger than the first spacing between two adjacent spiral segments in the outer spiral segment.

9. The microphone array according to any one of claims 1 to 8, characterized in that, Along the radial direction of the spiral array structure, the number of first microphones located on multiple spiral segments with a radius less than or equal to a predetermined value is n1, and the number of first microphones located on multiple spiral segments with a radius greater than the predetermined value is n2. n1 and n2 satisfy the relationship: n1≥n2.

10. The microphone array according to any one of claims 1 to 8, characterized in that, The sum of the number of the first microphone and the number of the second microphone is M, where M satisfies the following relationship: M ≤ 201; and / or, The number of the first microphones is N, and N satisfies the relationship: N≤200.

11. A microphone device, characterized in that, It includes a processor and a microphone array as described in any one of claims 1-10, wherein the processor is electrically connected to a microphone component in the microphone array.

12. A sound pickup method, characterized in that, The sound pickup method is implemented using the microphone device of claim 11, the microphone device comprising a microphone array, the microphone array comprising a plurality of first microphones arranged in a spiral array structure, and the method comprising the following steps: Phase compensation processing is performed on the acoustic signals picked up by multiple first microphones to synthesize a directional beam pointing towards the target direction for directional sound pickup.

13. The sound pickup method according to claim 12, characterized in that, The microphone array further includes a second microphone, the sum of the number of the first microphones and the number of the second microphones is M, the number of the first microphones located on a multi-turn spiral segment with a radius greater than a predetermined value is n2, and both the first microphones and the second microphones include full-range microphones. The method further includes: Receive audio signals collected by M of the first microphone and the second microphone; The first microphones process the audio signal with a frequency lower than a predetermined frequency using n2 of the first microphones and then output the first pickup signal. By using M of the first microphones and the second microphones, the audio signal with a frequency greater than the predetermined frequency is processed and a second pickup signal is output; and The first and second pickup signals are combined to output the third pickup signal.

14. The sound pickup method according to claim 13, characterized in that, The steps of processing the audio signal with a frequency lower than a predetermined frequency by the n2 first microphones include: A super-pointing algorithm is used to perform beamforming processing on the audio signal with a frequency lower than the predetermined frequency to output the first pickup signal; and / or, The step of processing the audio signal with a frequency greater than the predetermined frequency using M of the first microphones and the second microphones includes: A constant beamforming algorithm is used to beamform the audio signal with a frequency greater than the predetermined frequency in order to output the second pickup signal.

15. An audio system, characterized in that, The device includes the microphone device as described in claim 11 and the audio processing device, wherein the microphone device and the audio processing device are electrically connected.

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