Design method and system of semi-closed microphone soundproof cover

Abstract

The invention relates to a design method and system for a semi-closed microphone soundproof cover, and the method comprises the steps: S1, simplifying the semi-closed microphone soundproof cover into an impedance boundary small ball; s2, after noise sound waves are transmitted to the surfaces of the impedance boundary small balls, incident wave sound pressure and scattered wave sound pressure are formed, and impedance boundary conditions are constructed according to the incident wave sound pressure and the scattered wave sound pressure; s3, solving a modal coefficient of the scattered wave sound pressure according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition; and S4, designing the semi-closed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure. The semi-closed microphone sound-proof cover is creatively designed from the scattering layer of the sound-proof cover, and a new thought and a new direction are provided for the design of the semi-closed microphone sound-proof cover.

Description

Technical Field

[0001] The present invention relates to the technical field of semi-enclosed microphone design, and in particular to a design method and system for a semi-enclosed microphone soundproof cover. Background Art

[0002] The technical background of semi-enclosed microphone sound isolators stems from the continuous growth of demand for outdoor audio collection and noise suppression, especially in live broadcasts, conferences, military reconnaissance and other scenarios. Balancing the quality of sound collection and environmental noise control has become a key challenge. Its technological development is mainly reflected in the following aspects: First, driven by the demand for outdoor noise suppression, the semi-enclosed design suppresses noise while retaining sound details through a combination of partial shielding and sound-absorbing materials, becoming a compromise solution; second, innovation in acoustic materials and structures. Porous materials and composite materials are used for high-frequency noise absorption. At the same time, multi-layer structures, vacuum layers or sound insulation coatings are used to improve sound absorption efficiency and overall sound insulation performance. Structural optimization such as curved shields and parabolic mirrors reduce direct impact of sound waves through scattering and reflection; third, packaging and sealing technology advances, such as independent sub-cavity isolation, bent brackets and other technologies to reduce thermal interference, improve the audio signal-to-noise ratio, and provide internal noise control support for semi-enclosed designs; fourth, the integration of intelligence and AI technology. AI algorithms have become an important means to supplement physical sound insulation, such as Shank Wave. The T5 microphone uses AI to achieve noise reduction and signal-noise separation, and the Zvook system in the military field uses AI to enhance target detection capabilities in noisy environments; fifth, the diversified needs of application scenarios, and the requirements for sound isolators in different scenarios vary significantly, which has promoted the subdivision and optimization of semi-enclosed designs in structure, materials and functions; sixth, technical bottlenecks and breakthrough directions, low-frequency noise suppression, volume and performance balance, environmental adaptability, etc. are the current technical bottlenecks, which need to be combined with damping layers, mass-spring systems, etc. to achieve breakthroughs.

[0003] In general, the technological development of semi-enclosed microphone isolators is the result of the coordinated evolution of materials science, acoustic engineering, electronic packaging and AI algorithms. Its core goal is to achieve dual optimization of noise suppression and sound fidelity through structural innovation and multidisciplinary technology integration. In the future, this field will develop in the direction of integration, adaptability and high environmental adaptability.

[0004] While existing technologies for semi-enclosed microphone soundproofing enclosures primarily focus on noise suppression, acoustic performance optimization, structural stability, and application scenario requirements, with design features encompassing a semi-enclosed structure, multi-layered construction, and the use of high-frequency sound-absorbing materials, these technologies achieve dual optimization of noise suppression and sound fidelity through various approaches, while also addressing the needs of diverse scenarios. However, current designs for semi-enclosed microphone soundproofing enclosures primarily focus on sound absorption, resulting in low low-frequency sound absorption efficiency, a bulky design due to limited high-frequency sound-absorbing material thickness, and difficulty achieving full-band noise suppression through a single sound-absorbing mechanism. Furthermore, few approaches exist that consider the enclosure's scattering properties in designing semi-enclosed microphone soundproofing enclosures. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem that the design of semi-enclosed microphone sound insulation covers in the existing technology mostly focuses on the sound absorption level, resulting in low low-frequency sound absorption efficiency and difficulty in achieving full-band noise suppression through a single sound absorption mechanism.

[0006] To solve the above technical problems, the present invention provides a design method for a semi-enclosed microphone soundproof cover, comprising:

[0007] Step S1: simplifying the semi-enclosed microphone soundproof enclosure into an impedance boundary sphere;

[0008] Step S2: After the noise sound wave is transmitted to the surface of the impedance boundary sphere, an incident wave sound pressure and a scattered wave sound pressure are formed, and an impedance boundary condition is constructed according to the incident wave sound pressure and the scattered wave sound pressure;

[0009] Step S3: solving the modal coefficient of the scattered wave sound pressure according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition;

[0010] Step S4: designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

[0011] In one embodiment of the present invention, the incident wave sound pressure formula in step S2 is:

[0012]

[0013] Among them, p inc (r,θ) is the incident wave sound pressure; p0 is the incident wave amplitude; r is the distance from a point in the spherical coordinate system to the center of the circle; θ is the polar angle in the spherical coordinate system; J n (kr) is the nth-order Bessel function, describing the radial distribution of the incident wave in the spherical coordinate system; ∈ n is the Neumann factor, which is used to ensure the convergence of the series; i n is the phase factor, i is the imaginary unit, n is the modal order; k is the wave number.

[0014] In one embodiment of the present invention, the formula for the scattered wave sound pressure in step S2 is:

[0015]

[0016] Among them, p scat (r,θ) is the sound pressure of the scattered wave; is the nth-order first-kind Hankel function, describing the outward scattered wave; A n is the modal coefficient to be determined.

[0017] In one embodiment of the present invention, the method of constructing the impedance boundary condition according to the incident wave sound pressure and the scattered wave sound pressure in step S2 includes:

[0018] The impedance boundary condition is constructed based on the incident wave sound pressure and the scattered wave sound pressure, and the total sound pressure P total The radial velocity of the air satisfies the following conditions at r = a on the surface of the impedance boundary sphere:

[0019]

[0020] Where Z is the impedance boundary condition; r is the direction pointing outward from the sphere along the center of the sphere in the spherical coordinate system established with the sphere axis; a is the radius of the impedance boundary sphere; the total sound pressure P total is the incident wave sound pressure P inc Add the scattered wave sound pressure P scat ; p represents the single wave sound pressure, which represents the incident wave sound pressure or the scattered wave sound pressure; v r is the radial velocity of the air.

[0021] In one embodiment of the present invention, the modal coefficient A of the scattered wave sound pressure is solved in step S3 according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition. n The methods include:

[0022] Substituting formula (1) and formula (2) into formula (3), we can get the expression for Z:

[0023]

[0024] According to formula (4), the normalization parameter β is constructed and defined as:

[0025]

[0026] Where ρ0 is the air density;

[0027] Combining formula (5) with formula (6) for wave number k, formula (4) can be simplified to obtain formula (7):

[0028]

[0029] Where ω is the angular frequency of the noise and ω = 2πf, f is the noise frequency; c is the speed of sound; is the derivative of the first-order Hankel function of the first kind;

[0030] The modal coefficient A is obtained based on formula (7): n .

[0031] In one embodiment of the present invention, the modal coefficient A is obtained based on formula (7): n , expressed as:

[0032]

[0033] Among them, J′ n (ka) is the derivative of the nth order Bessel function.

[0034] In one embodiment of the present invention, the method of designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 includes: when the noise frequency f is constant, the larger the modulus square of the modal coefficient of the scattered wave sound pressure, the better the sound insulation effect of the semi-enclosed microphone sound insulation cover.

[0035] In one embodiment of the present invention, the method of designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 also includes: when the noise frequency f is constant, the scattered wave sound pressure changes with the change of the impedance boundary condition Z, and the impedance boundary condition Z of the preset microphone sound insulation cover material is selected to maximize the modulus square of the modal coefficient of the scattered wave sound pressure, so as to improve the sound insulation effect of the semi-enclosed microphone sound insulation cover.

[0036] In one embodiment of the present invention, the method of designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 also includes: selecting the radius of the microphone sound insulation cover, and determining the thickness range of the microphone sound insulation cover according to the radius and the spatial range of the microphone sound insulation cover; determining the mapping relationship between the impedance boundary condition Z of the microphone sound insulation cover and different noise frequencies f under different microphone sound insulation cover material resistivities, and determining the optimal combination of microphone sound insulation cover material thickness and resistivity under different noise frequencies f, and selecting the corresponding impedance boundary condition Z so that the modulus square of the scattered wave sound pressure modal coefficient within the target noise frequency band reaches the maximum value, thereby realizing the suppression of broadband noise by the microphone sound insulation cover.

[0037] To solve the above technical problems, the present invention provides a design system for a semi-enclosed microphone soundproof enclosure, comprising:

[0038] Simplification module: used to simplify the semi-enclosed microphone soundproof cover into an impedance boundary sphere;

[0039] Construction module: used for forming incident wave sound pressure and scattered wave sound pressure after the noise sound wave is transmitted to the surface of the impedance boundary sphere, and constructing the impedance boundary condition according to the incident wave sound pressure and scattered wave sound pressure;

[0040] Solution module: used to solve the modal coefficients of scattered wave sound pressure based on the incident wave sound pressure, scattered wave sound pressure and impedance boundary conditions;

[0041] Design module: used for designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

[0042] In order to solve the above technical problems, the present invention provides an electronic device, including a memory, a processor and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the steps of the design method of the semi-enclosed microphone soundproof cover as mentioned above are implemented.

[0043] In order to solve the above technical problems, the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the design method of the semi-enclosed microphone sound insulation cover as mentioned above are implemented.

[0044] The above technical solution of the present invention has the following advantages over the prior art:

[0045] The design method of the semi-enclosed microphone soundproof cover constructed by the present invention creatively designs the semi-enclosed microphone soundproof cover based on the scattering level of the soundproof cover, providing a new idea and direction for the design of the semi-enclosed microphone soundproof cover;

[0046] The semi-enclosed microphone soundproof cover constructed by the method of the present invention can reduce the reverberation of the room to a certain extent by reducing the sound reflected by the wall behind the microphone and reducing the standing wave interference, making the sound cleaner, more solid and clearer, and making the recorded sound clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0048] Figure 1 is a flow chart of the method of the present invention;

[0049] Figure 2 In the embodiment of the present invention, when the noise frequency is 5000 Hz and the radius of the impedance boundary sphere is 0.2 m, A n The curve of the integral result versus the change of acoustic impedance Z;

[0050] Figure 33 is a graph showing the variation of the square of the acoustic pressure modulus of the impedance boundary sphere scattered wave with the acoustic impedance Z when the noise frequency is 5000 Hz in an embodiment of the present invention;

[0051] Figure 4 is a graph showing the variation of the square of the scattered wave acoustic pressure modulus with the acoustic impedance Z at different noise frequencies in an embodiment of the present invention;

[0052] Figure 5 The flow resistance of the embodiment of the present invention with a thickness of 5 cm is 9760 Pa*s / m 2 Material acoustic impedance curve;

[0053] Figure 6 In the embodiment of the present invention, the flow resistance is 9760Pa*s / m based on a thickness of 5cm. 2 Comparison of noise reduction effects between the sound insulation balls made of the material and those without sound insulation balls;

[0054] Figure 7 Schematic diagram of a simplified model of a semi-enclosed microphone soundproof enclosure with a 90° opening of the ball in an embodiment of the present invention;

[0055] Figure 8 This is a comparison chart of the noise reduction effect of a closed microphone soundproof cover established with a 90° opening of the ball in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0057] Example 1

[0058] Reference Figure 1 The present invention relates to a design method for a semi-enclosed microphone soundproof cover, comprising:

[0059] Step S1: simplifying the semi-enclosed microphone soundproof enclosure into an impedance boundary sphere;

[0060] Step S2: After the noise sound wave is transmitted to the surface of the impedance boundary sphere, an incident wave sound pressure and a scattered wave sound pressure are formed, and an impedance boundary condition is constructed according to the incident wave sound pressure and the scattered wave sound pressure;

[0061] Step S3: solving the modal coefficient of the scattered wave sound pressure according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition;

[0062] Step S4: designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

[0063] The following is a detailed introduction to this embodiment:

[0064] Step S1: After simplifying the semi-enclosed microphone soundproof cover into an impedance boundary sphere, this embodiment can place the microphone at the geometric center of the sphere.

[0065] In step S2, this embodiment expands the incident wave sound pressure into formula (1):

[0066]

[0067] Among them, p inc (r,θ) is the incident wave sound pressure; p0 is the incident wave amplitude; r is the distance from a point in the spherical coordinate system to the center of the circle; θ is the polar angle in the spherical coordinate system; J n (kr) is the nth-order Bessel function, describing the radial distribution of the incident wave in the spherical coordinate system; ∈ n is the Neumann factor, ∈0=1, ∈ n =2(n≥1), used to ensure the convergence of the series; i n is the phase factor, i is the imaginary unit, n is the modal order; k is the wave number, which is the angular frequency ω of the noise divided by the sound speed c.

[0068] At the same time, in step S2, this embodiment expands the scattered wave sound pressure into formula (2):

[0069]

[0070] Among them, p scat (r,θ) is the sound pressure of the scattered wave; is the nth-order first-kind Hankel function, describing the outward scattered wave; A n is the modal coefficient to be determined, which is determined by the boundary conditions.

[0071] Next, the method of constructing the impedance boundary condition according to the incident wave sound pressure and the scattered wave sound pressure in step S2 includes:

[0072] Total sound pressure P total The radial velocity of the air satisfies the formula (3) at r = a (r is the direction pointing outward from the center of the sphere in the spherical coordinate system established with the axis of the sphere, and a is the radius of the sphere of the impedance boundary sphere) on the surface of the sphere of the impedance boundary sphere:

[0073]

[0074] Where Z is the impedance boundary condition of the impedance boundary sphere (abbreviated as acoustic impedance); P total =P inc +P scat is the incident wave sound pressure plus the scattered wave sound pressure, P inc is the incident wave sound pressure; P scatis the scattered wave sound pressure; p represents the single wave sound pressure, which represents the incident wave or scattered wave sound pressure; v r is the radial velocity of the air.

[0075] In step S3, the modal coefficient A of the scattered wave sound pressure is solved according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition. n The methods include:

[0076] Substituting the above formulas (1) and (2) into formula (3), we can obtain the expression for Z:

[0077]

[0078] According to formula (4), the normalization parameter β is constructed and defined as:

[0079]

[0080] where ρ0 is the air density.

[0081] Combining formula (5) with formula (6) for wave number k, formula (4) can be simplified to obtain formula (7):

[0082]

[0083] Where ω is the angular frequency of the noise and ω = 2πf, f is the noise frequency; c is the speed of sound; is the derivative of the first-order Hankel function of the first kind;

[0084] The modal coefficient A is obtained based on formula (7): n , expressed as:

[0085]

[0086] Among them, J′ n (ka) is the derivative of the nth order Bessel function.

[0087] Furthermore, the method for designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure in step S4 includes: when the noise frequency f is constant (determined value), the modal coefficient A of the scattered wave sound pressure is n The larger the square of the modulus, the better the sound insulation effect of the semi-enclosed microphone soundproof cover.

[0088] The purpose of this embodiment is to separate the noise through the semi-enclosed microphone soundproof cover (i.e., the impedance boundary sphere) into incident wave sound pressure and scattered wave sound pressure. The incident wave sound pressure penetrates the impedance boundary sphere and affects the sound of the microphone. To this end, this embodiment aims to minimize the incident wave sound pressure, that is, to maximize the scattered wave sound pressure (the scattered wave formed by the noise on the surface of the impedance boundary sphere). Specifically, this embodiment obtains the theoretical solution of the scattered sound pressure (i.e., A obtained by formula (8)) through the above method. n By observing formula (8), we can solve (A n ), when the position where the scattered wave sound pressure is measured and the frequency f of the noise are determined, is a constant, and cos(nθ) in formula (2) is the spatial distribution of the angle and does not determine the sound pressure amplitude. Therefore, the amplitude of the scattered wave sound pressure only depends on A n Since the scattered wave energy is proportional to the square of the scattered wave sound pressure, and the scattered wave sound pressure is proportional to A n Therefore, in order to make the scattered wave energy as large as possible, the square of the scattered wave sound pressure modulus should be made as large as possible, that is, A n The square of the modulus is as large as possible, A n The key to designing a semi-enclosed microphone soundproof cover in this embodiment is to make the module square as large as possible.

[0089] Combining formula (2) and formula (8), it is not difficult to see that the scattered wave sound pressure at a certain point on the surface of the impedance boundary sphere at a specific noise frequency f changes with the change of the acoustic impedance Z. When the noise frequency f is 5000Hz and the impedance boundary sphere radius c=0.2m, A n The absolute value of the integral from n = 0 to n = ∞ is integrated as the acoustic impedance Z changes. Figure 2 As shown (assuming p0=1, take θ=0). Figure 2 This is the theoretical calculation value of the square of the scattered wave sound pressure versus the change in the material acoustic impedance. Figure 2 It can be seen that when the noise frequency is 5000 Hz, the acoustic impedance Z has a large squared value of the scattered wave sound pressure in the range of 0-1000 Pa*s / m. Therefore, in this embodiment, when establishing a fine model simulation, the acoustic impedance Z of 0-1000 Pa*s / m can be focused on.

[0090] According to the above analysis, this embodiment requires the soundproof cover to remove the incident wave sound pressure as much as possible, so this embodiment needs to find a suitable acoustic impedance Z so that A n The square of the modulus is the largest. A under different noise frequencies n The square of the modulus (|A n | 2 ) changes with the curve of acoustic impedance Z. For a noise frequency, let |A n | 2The maximum acoustic impedance Z may not be the maximum for other noise frequencies. Moreover, the acoustic impedance Z of actual materials will also change with the noise frequency. Therefore, this embodiment needs to find a material with a certain thickness and a flow resistivity (the flow resistivity does not change with the noise frequency) so that the acoustic impedance Z of the material of this thickness reaches |A at as many noise frequencies as possible. n | 2 The maximum value of .

[0091] This embodiment simulates and calculates the change of the square of the acoustic pressure modulus of the scattered wave of the ball with the acoustic impedance Z. When the noise frequency f is 5000Hz, as shown in Figure 3 As shown, from Figure 3 It can be seen that the simulation results are generally consistent with the conclusions of this embodiment. The difference may be that: as the acoustic impedance Z increases, the sound pressure of the reflected wave increases, and the amplitude of the scattered wave is changed due to the superposition effect of the sound pressure of the scattered wave and the sound pressure of the incident wave. Specifically, by analyzing the noise frequencies |A n | 2 By analyzing the changing characteristics of acoustic impedance Z, the following conclusions can be drawn: 1. Wide-band optimization requires balancing multiple objectives: Experiments show that a single noise frequency can be found to make |A n | 2 The optimal acoustic impedance Z is maximized, but the scattering efficiency of this acoustic impedance Z for other noise frequency bands is attenuated. Therefore, it is necessary to select the acoustic impedance curve of the actual material to maximize the scattering efficiency of multiple target noise frequencies. n | 2 Materials are all in the high value area to improve broadband sound insulation performance. 2. Analysis of the differences between theoretical model and simulation: Figure 3 The deviation between the theoretical and simulation curves may be due to the spatial superposition effect of the field. The reflected wave in the high-impedance region is enhanced, resulting in standing wave interference between the incident and reflected waves at the interface, which in turn affects the sound pressure distribution of the scattered wave.

[0092] Furthermore, the method for designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 also includes: selecting the radius of the microphone sound insulation cover, and determining the thickness range of the microphone sound insulation cover according to the radius and the spatial range of the microphone sound insulation cover. On the basis of determining the thickness range of the microphone sound insulation cover, a mapping relationship between the surface acoustic impedance Z of the microphone sound insulation cover material and the noise frequency f is established under different flow resistivities of the microphone sound insulation cover material, and then the modulus square distribution characteristics of the modal coefficient of the scattered wave sound pressure under noise of different frequency bands are analyzed. Finally, under different noise frequencies f, the optimal combination of material thickness and flow resistivity is determined through a parameter optimization algorithm, and the corresponding acoustic impedance Z is selected so that the modulus square value of the modal coefficient of the scattered wave sound pressure |A is within the target noise frequency band. n | 2 Reach the maximum, so that the microphone sound insulation cover can effectively suppress broadband noise.

[0093] Experimental analysis:

[0094] Based on the above theory, this embodiment designs a soundproof enclosure with a radius of 20 cm. Using comsol simulation, a schematic diagram of the change of the square of the scattered wave sound pressure modulus of the soundproof ball at different frequencies with the acoustic impedance Z is obtained. For details, please see Figure 4 ,from Figure 4 The simulation results show that when the acoustic impedance Z is 381 Pa*s / m, the square of the acoustic pressure modulus of most scattered waves reaches a maximum value. Therefore, in this embodiment, a material with an acoustic impedance Z of 381 Pa*s / m can be selected as the material of the microphone soundproof cover.

[0095] Through comsol simulation, the acoustic impedance Z of the material changes with the noise frequency. In this example, the flow resistance of a material with a thickness of 5 cm is found to be 9760 Pa*s / m 2 The acoustic impedance Z of the material is around 381Pa*s / m. The acoustic impedance Z of this material can achieve a large |A under broadband noise. n | 2 To ensure that most of the noise energy is scattered in a wide frequency range, it means that the material with this parameter can scatter as much sound pressure as possible in a wide frequency range. Figure 5 shown.

[0096] At this time, this embodiment can obtain a sound insulation impedance boundary sphere with an outer diameter of 20 cm and an inner diameter of 15 cm. The sound pressure level at the center of the sphere is compared with the sound pressure level without the sound insulation sphere. Figure 6 shown. Figure 6 It can be seen that the noise level without sound insulation is 91dB, and when the sound insulation impedance boundary balls are added, the noise level is about 84dB, and the noise reduction effect is 7dB, indicating that the noise reduction effect of the balls is relatively stable.

[0097] Since this embodiment studies a semi-enclosed microphone soundproof cover, this embodiment opens a 90° opening in the impedance boundary sphere constructed of the above materials to place acoustic instruments such as microphones and speakers. Figure 7 Now the comparison between the sound pressure level at the center of the impedance boundary sphere (also known as the soundproof enclosure) and the air sound pressure level is as follows: Figure 8 As shown, from Figure 8 It can be seen that the sound pressure level in the soundproof enclosure is stable at around 84dB, and the noise reduction effect is 7dB. Figure 6 The change is not significant, indicating that the noise reduction effect of the small ball with a 90° opening is stable.

[0098] Example 2

[0099] This embodiment provides a design system for a semi-enclosed microphone soundproof enclosure, including:

[0100] Simplification module: used to simplify the semi-enclosed microphone soundproof cover into an impedance boundary sphere;

[0101] Construction module: used for forming incident wave sound pressure and scattered wave sound pressure after the noise sound wave is transmitted to the surface of the impedance boundary sphere, and constructing the impedance boundary condition according to the incident wave sound pressure and scattered wave sound pressure;

[0102] Solution module: used to solve the modal coefficients of scattered wave sound pressure based on the incident wave sound pressure, scattered wave sound pressure and impedance boundary conditions;

[0103] Design module: used for designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

[0104] Example 3

[0105] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for designing a semi-enclosed microphone soundproof cover described in Example 1 are implemented.

[0106] Example 4

[0107] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for designing a semi-enclosed microphone soundproof cover described in the first embodiment are implemented.

[0108] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0109] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0112] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0113] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A design method for a semi-enclosed microphone soundproof cover, characterized by: include: Step S1: simplifying the semi-enclosed microphone soundproof enclosure into an impedance boundary sphere; Step S2: After the noise sound wave is transmitted to the surface of the impedance boundary sphere, an incident wave sound pressure and a scattered wave sound pressure are formed, and an impedance boundary condition is constructed according to the incident wave sound pressure and the scattered wave sound pressure; Step S3: solving the modal coefficient of the scattered wave sound pressure according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition; Step S4: designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

2. The design method of a semi-enclosed microphone soundproof cover according to claim 1, characterized in that: The incident wave sound pressure formula in step S2 is: Among them, p inc (r,θ) is the incident wave sound pressure; p0 is the incident wave amplitude; r is the distance from a point in the spherical coordinate system to the center of the circle; θ is the polar angle in the spherical coordinate system; J n (kr) is the nth-order Bessel function, describing the radial distribution of the incident wave in the spherical coordinate system; ∈ n is the Neumann factor, which is used to ensure the convergence of the series; i n is the phase factor, i is the imaginary unit, n is the modal order; k is the wave number.

3. The design method of a semi-enclosed microphone soundproof cover according to claim 2, characterized in that: The formula for the scattered wave sound pressure in step S2 is: Among them, p scat (r,θ) is the sound pressure of the scattered wave; is the nth-order first-kind Hankel function, describing the outward scattered wave; A n is the modal coefficient to be determined.

4. The design method of a semi-enclosed microphone soundproof cover according to claim 3, characterized in that: The method for constructing the impedance boundary condition according to the incident wave sound pressure and the scattered wave sound pressure in step S2 includes: The impedance boundary condition is constructed based on the incident wave sound pressure and the scattered wave sound pressure, and the total sound pressure P total The radial velocity of the air satisfies the following conditions at r = a on the surface of the impedance boundary sphere: Where Z is the impedance boundary condition; r is the direction pointing outward from the sphere along the center of the sphere in the spherical coordinate system established with the sphere axis; a is the radius of the impedance boundary sphere; the total sound pressure P total is the incident wave sound pressure P inc Add the scattered wave sound pressure P scat ; p represents the single wave sound pressure, which represents the incident wave sound pressure or the scattered wave sound pressure; v r is the radial velocity of the air.

5. The design method of a semi-enclosed microphone soundproof cover according to claim 4, characterized in that: In step S3, the modal coefficient A of the scattered wave sound pressure is solved according to the incident wave sound pressure, the scattered wave sound pressure and the impedance boundary condition. n The methods include: Substituting formula (1) and formula (2) into formula (3), we can get the expression for Z: According to formula (4), the normalization parameter β is constructed and defined as: Where ρ0 is the air density; Combining formula (5) with formula (6) for wave number k, formula (4) can be simplified to obtain formula (7): Where ω is the angular frequency of the noise and ω = 2πf, f is the noise frequency; c is the speed of sound; is the derivative of the first-order Hankel function of the first kind; The modal coefficient A is obtained based on formula (7): n .

6. The method for designing a semi-enclosed microphone soundproof enclosure according to claim 5, characterized in that: The modal coefficient A is obtained based on formula (7): n , expressed as: Among them, J' n (ka) is the derivative of the nth order Bessel function.

7. The method for designing a semi-enclosed microphone soundproof enclosure according to claim 1, wherein: The method of designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure in step S4 includes: when the noise frequency f is constant, the larger the modulus square of the modal coefficient of the scattered wave sound pressure, the better the sound insulation effect of the semi-enclosed microphone soundproof cover.

8. The method for designing a semi-enclosed microphone soundproof cover according to claim 1, characterized in that: The method of designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 also includes: when the noise frequency f is constant, the scattered wave sound pressure changes with the change of the impedance boundary condition Z, and the impedance boundary condition Z of the preset microphone sound insulation cover material is selected to maximize the modulus square of the modal coefficient of the scattered wave sound pressure, so as to improve the sound insulation effect of the semi-enclosed microphone sound insulation cover.

9. The method for designing a semi-enclosed microphone soundproof cover according to claim 1, characterized in that: The method for designing a semi-enclosed microphone sound insulation cover according to the modal coefficient of the scattered wave sound pressure in step S4 also includes: selecting the radius of the microphone sound insulation cover, and determining the thickness range of the microphone sound insulation cover according to the radius and the spatial range of the microphone sound insulation cover; determining the mapping relationship between the impedance boundary condition Z of the microphone sound insulation cover and different noise frequencies f under different microphone sound insulation cover material resistivities, and determining the optimal combination of microphone sound insulation cover material thickness and resistivity under different noise frequencies f, and selecting the corresponding impedance boundary condition Z so that the modulus square of the scattered wave sound pressure modal coefficient reaches the maximum value within the target noise frequency band, thereby achieving the suppression of broadband noise by the microphone sound insulation cover.

10. A design system for a semi-enclosed microphone soundproof enclosure, characterized by: include: Simplification module: used to simplify the semi-enclosed microphone soundproof cover into an impedance boundary sphere; Construction module: used for forming incident wave sound pressure and scattered wave sound pressure after the noise sound wave is transmitted to the surface of the impedance boundary sphere, and constructing the impedance boundary condition according to the incident wave sound pressure and scattered wave sound pressure; Solution module: used to solve the modal coefficients of scattered wave sound pressure based on the incident wave sound pressure, scattered wave sound pressure and impedance boundary conditions; Design module: used for designing a semi-enclosed microphone soundproof cover according to the modal coefficient of the scattered wave sound pressure.

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