Methods, apparatus, electronic equipment and readable media for measuring acoustic impedance of materials

Abstract

This disclosure provides embodiments of a method, apparatus, electronic device, and readable medium for measuring the acoustic impedance of materials. One specific implementation of the method includes: determining a first signal group in a first state and a second signal group in a second state for the material acoustic impedance measuring device; determining a first solution equation and a second solution equation based on the first signal group, the second signal group, and the acoustic impedance solution model corresponding to the material acoustic impedance measuring device; solving the first solution equation and the second solution equation for acoustic impedance parameters to obtain a first solution acoustic impedance and a second solution acoustic impedance; and determining the acoustic impedance of the measurement area of ​​the material to be measured based on the first solution acoustic impedance and the second solution acoustic impedance. This implementation can measure the acoustic impedance of the measurement area of ​​the material to be measured with extremely high accuracy.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of computer technology, and more specifically to methods, apparatus, electronic devices, and readable media for measuring the acoustic impedance of materials. Background Technology

[0002] Because different tuning materials (such as headphone tuning cloth used for headphone tuning) often have different characteristic acoustic impedances, their impact on the acoustic components being tuned will also vary. Currently, common tuning materials, such as headphone tuning cloth, often only provide parameters such as mesh count and material composition, but not their corresponding characteristic acoustic impedance. Therefore, it is necessary to measure the corresponding characteristic acoustic impedance of tuning materials separately. Currently, the common method for measuring characteristic acoustic impedance is to construct an acoustic model based on the acoustic characteristics of the test system for measuring the characteristic acoustic impedance of the tuning materials.

[0003] However, the inventors discovered that the following technical problems often arise when using the above method:

[0004] The electrical characteristics of the circuit and the mechanical characteristics of the hardware used for characteristic acoustic impedance measurement often have a significant impact on the measurement of characteristic acoustic impedance. Ignoring electrical and mechanical characteristics will result in low accuracy of the measured characteristic acoustic impedance.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background of the inventive concept, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0007] Some embodiments of this disclosure provide methods, apparatus, electronic devices, and readable media for measuring the acoustic impedance of materials to address one or more of the technical problems mentioned in the background section above.

[0008] In a first aspect, some embodiments of this disclosure provide a method for measuring the acoustic impedance of a material. The method includes: determining a first signal group in a first state and a second signal group in a second state for a material acoustic impedance measuring device, wherein the first and second signal groups each include a voltage signal, and each further includes at least one of a sound pressure signal and a current signal. The voltage signal is the voltage signal of a loudspeaker included in the material acoustic impedance measuring device; the sound pressure signal is the sound pressure signal acquired at an observation point location opposite to the loudspeaker in the material acoustic impedance measuring device; the current signal is the current signal of the loudspeaker; and the second state indicates that the outlet of the thin tube included in the material acoustic impedance measuring device is covered by the measurement area of ​​the material to be measured. The method further includes: determining a first solution equation and a second solution equation based on the first signal group, the second signal group, and the acoustic impedance solution model corresponding to the material acoustic impedance measuring device; solving the first solution equation and the second solution equation for acoustic impedance parameters to obtain a first solved acoustic impedance and a second solved acoustic impedance; and determining the acoustic impedance of the measurement area of ​​the material to be measured based on the first solved acoustic impedance and the second solved acoustic impedance.

[0009] Optionally, the above-mentioned solution of the first and second equations for acoustic impedance parameters to obtain the first and second acoustic impedances includes: under the premise that the acoustic impedance solution model satisfies at least one target condition in the target condition group, the acoustic impedance parameters of the first and second equations for acoustic impedance parameters are solved to obtain the first and second acoustic impedances, wherein the target condition group includes: a first target condition and a second target condition, the first target condition being: the speaker parameters included in the acoustic impedance solution model for the speaker are fixed, and the second target condition being: the acoustic parameters included in the acoustic impedance solution model for the internal space of the material acoustic impedance measuring device are fixed.

[0010] Optionally, the above method further includes: determining the characteristic acoustic resistance of the material to be measured based on the acoustic resistance of the measurement area and the outlet area of ​​the capillary tube.

[0011] Optionally, determining the first and second solution equations based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device includes: in response to determining that the first signal group includes a current signal and the second signal group includes a current signal, substituting the ratio of the current signal and voltage signal included in the first signal group at each first frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each first frequency; and substituting the ratio of the current signal and voltage signal included in the second signal group at each second frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each second frequency.

[0012] Optionally, determining the first and second solution equations based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device includes: in response to determining that the first signal group includes a current signal and a sound pressure signal, and that the second signal group includes a current signal and a sound pressure signal, performing the following processing steps: substituting the ratio of the current signal and voltage signal included in the first signal group at each third frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each third frequency; substituting the ratio of the voltage signal and sound pressure signal included in the first signal group at each fourth frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each fourth frequency; substituting the ratio of the current signal and voltage signal included in the second signal group at each fifth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each fifth frequency; and substituting the ratio of the voltage signal and sound pressure signal included in the second signal group at each sixth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each sixth frequency.

[0013] Optionally, the above-mentioned solution of the first and second solution equations to obtain the first and second solution acoustic impedances includes: randomly generating a first and a second initial solution array; solving the acoustic impedance parameters of the first solution equations corresponding to each of the third frequencies according to the first initial solution array to obtain a first reference solution array; solving the acoustic impedance parameters of the first solution equations corresponding to each of the fourth frequencies according to the first reference solution array to obtain the first solution acoustic impedance; solving the acoustic impedance parameters of the second solution equations corresponding to each of the fifth frequencies according to the second initial solution array to obtain a second reference solution array; and solving the acoustic impedance parameters of the second solution equations corresponding to each of the sixth frequencies according to the second reference solution array to obtain the second solution acoustic impedance.

[0014] Secondly, some embodiments of this disclosure provide a material acoustic impedance measuring device, the device comprising: a cavity; a loudspeaker, wherein the loudspeaker is disposed on a first side of the cavity and the sound-emitting direction of the loudspeaker is towards the interior of the cavity; a thin tube, wherein the thin tube is located on a second side of the cavity and communicates with the cavity; and a material to be measured for acoustic impedance, wherein the measurement area of ​​the material to be measured is sealed and covers the outlet of the thin tube, and the material to be measured for acoustic impedance is a material whose acoustic impedance of the corresponding measurement area is to be determined by the acoustic impedance solution model corresponding to the material acoustic impedance measuring device.

[0015] Optionally, the above-mentioned material acoustic impedance measuring device further includes a microphone unit, wherein the microphone unit is disposed inside the cavity at an observation point position opposite to the speaker.

[0016] Thirdly, some embodiments of this disclosure provide an electronic device, including: one or more processors; and a storage device having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any implementation of the first aspect above.

[0017] Fourthly, some embodiments of this disclosure provide a computer-readable medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method described in any of the implementations of the first aspect above.

[0018] The above-described embodiments of this disclosure have the following beneficial effects: the material acoustic impedance measurement method of some embodiments of this disclosure improves the accuracy of the acoustic impedance of the measurement area of ​​the material to be measured. Specifically, the reason for the low accuracy of characteristic acoustic impedance measurement is that the electrical characteristics of the circuit and the mechanical characteristics of the hardware used for characteristic acoustic impedance measurement often have a significant impact on the measurement of characteristic acoustic impedance. Ignoring the electrical and mechanical characteristics will lead to low accuracy of the measured characteristic acoustic impedance. Based on this, the material acoustic impedance measurement method of some embodiments of this disclosure firstly determines a first signal group in a first state and a second signal group in a second state of the material acoustic impedance measurement device. The first and second signal groups respectively include voltage signals, and the first and second signal groups respectively also include at least one of sound pressure signals and current signals. The voltage signal is the voltage signal of the loudspeaker included in the material acoustic impedance measurement device, the sound pressure signal is the sound pressure signal collected at the observation point position opposite to the loudspeaker in the material acoustic impedance measurement device, and the current signal is the current signal of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic impedance measurement device is covered by the measurement area of ​​the material to be measured. This is used to determine the different electrical and acoustic signals of the material acoustic impedance measuring device under a reference state (first state) and a state covering the material to be measured (second state). Next, based on the first signal group, the second signal group, and the acoustic impedance solution model corresponding to the material acoustic impedance measuring device, a first solution equation and a second solution equation are determined. The acoustic impedance solution model can be an acoustic model, mechanical model, or electrical model constructed based on the material acoustic impedance measuring device. Further, the acoustic impedance parameters are solved for the first and second solution equations to obtain the first and second solved acoustic impedances. This yields the acoustic impedance under the reference state (first solved acoustic impedance) and the acoustic impedance under the second state (second solved acoustic impedance). Finally, based on the first and second solved acoustic impedances, the acoustic impedance of the measurement area of ​​the material to be measured is determined. By using the acoustic impedance solution model constructed based on the acoustic, electrical, and mechanical characteristics of the material acoustic impedance measuring device, the acoustic impedance of the measurement area of ​​the material to be measured is thus measured with extremely high accuracy. Attached Figure Description

[0019] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0020] Figure 1 This is a schematic diagram of an application scenario of the material acoustic impedance measurement method according to some embodiments of this disclosure;

[0021] Figure 2 This is a flowchart of some embodiments of the material acoustic impedance measurement method according to the present disclosure;

[0022] Figure 3 These are flowcharts of some other embodiments of the material acoustic impedance measurement method according to this disclosure;

[0023] Figure 4 This is a flowchart of some further embodiments of the material acoustic impedance measurement method according to the present disclosure;

[0024] Figure 5 This is a flowchart for solving the acoustic impedance parameters using the first and second solution equations.

[0025] Figure 6 These are schematic diagrams of some embodiments of the material acoustic impedance measuring device according to this disclosure;

[0026] Figure 7 This is a schematic diagram of the structure of an electronic device suitable for implementing some embodiments of the present disclosure. Detailed Implementation

[0027] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0028] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0029] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0030] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0031] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0032] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] Figure 1 This is a schematic diagram illustrating an application scenario of the material acoustic impedance measurement method according to some embodiments of this disclosure.

[0034] exist Figure 1 In this application scenario, the computing device 101 can first determine a first signal group 102 in a first state and a second signal group 103 in a second state for the material acoustic impedance measuring device. The first signal group 102 and the second signal group 103 each include a voltage signal, and each also includes at least one of a sound pressure signal and a current signal. The voltage signal is the voltage signal of the loudspeaker included in the material acoustic impedance measuring device. The sound pressure signal is the sound pressure signal acquired at an observation point location opposite the loudspeaker in the material acoustic impedance measuring device. The current signal is the current signal of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic impedance measuring device is covered by the measurement area of ​​the material to be measured. In this application scenario, the first signal group 102 can include signal waveform diagrams of the voltage signal, sound pressure signal, and current signal of the material acoustic impedance measuring device in the first state. The second signal group 103 can include signal waveform diagrams of the voltage signal, sound pressure signal, and current signal of the material acoustic impedance measuring device in the second state. Secondly, the computing device 101 can determine the first solution equation 105 and the second solution equation 106 based on the acoustic impedance solution model 104 corresponding to the first signal group 102, the second signal group 103, and the material acoustic impedance measurement device, respectively. Next, the computing device 101 can solve the acoustic impedance parameters of the first solution equation 105 and the second solution equation 106, respectively, to obtain the first solution acoustic impedance 107 and the second solution acoustic impedance 108. Finally, the computing device 101 can determine the acoustic impedance 109 of the measurement area of ​​the material to be measured based on the first solution acoustic impedance 107 and the second solution acoustic impedance 108.

[0035] It should be noted that the aforementioned computing device 101 can be either hardware or software. When the computing device is hardware, it can be implemented as a distributed cluster consisting of multiple servers or terminal devices, or as a single server or a single terminal device. When the computing device is software, it can be installed within the hardware devices listed above. It can be implemented as, for example, multiple software programs or software modules used to provide distributed services, or as a single software program or software module. No specific limitations are made here.

[0036] It should be understood that Figure 1 The number of computing devices shown is merely illustrative. Any number of computing devices can be used depending on implementation needs.

[0037] Continue to refer to Figure 2 The flowchart 200 illustrates some embodiments of a material acoustic impedance measurement method according to the present disclosure. The material acoustic impedance measurement method includes the following steps:

[0038] Step 201: Determine the first signal group of the material acoustic impedance measuring device in the first state and the second signal group in the second state.

[0039] In some embodiments, the subject performing the material acoustic impedance measurement method (e.g. Figure 1 The computing device 101 shown can determine a first signal group in a first state and a second signal group in a second state of the material acoustic resistance measuring device. The first and second signal groups each include a voltage signal. The first and second signal groups each also include at least one of a sound pressure signal and a current signal. The voltage signal is the voltage signal of the loudspeaker included in the material acoustic resistance measuring device. The sound pressure signal is the sound pressure signal acquired at an observation point location opposite the loudspeaker in the material acoustic resistance measuring device. The current signal is the current signal of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic resistance measuring device is covered by the measurement area of ​​the material to be measured. The material acoustic resistance measuring device can be a device for determining the acoustic resistance and characteristic acoustic resistance of the measurement area of ​​the material to be measured. The first state indicates a reference state. For example, the first state can indicate that the outlet of the thin tube included in the material acoustic resistance measuring device is not covered. Alternatively, the first state can also indicate that the outlet of the thin tube included in the material acoustic resistance measuring device is covered by a material with known characteristic acoustic resistance.

[0040] In practice, the current signal can be the alternating current signal (AC signal) of the speaker coil included in the speaker. The voltage signal can be the input voltage signal of the speaker coil included in the speaker. The above observation point can be set inside the above-mentioned material acoustic impedance measuring device.

[0041] In some optional implementations of certain embodiments, the aforementioned executing entity can determine the first signal group of the material acoustic impedance measuring device in a first state and the second signal group in a second state, respectively, while limiting the speaker output volume. In practice, because sound waves are constantly reflected inside the material acoustic impedance measuring device, a high volume may cause high sound pressure within the speaker characteristic parameter testing device, placing the acoustic acquisition equipment in a non-linear region. This can lead to clipping distortion in the acquired sound pressure signal. Therefore, determining the first signal group in the first state and the second signal group in the second state while limiting the output volume can avoid this phenomenon. Furthermore, the limitation on the speaker output volume must not be lower than a preset volume threshold to avoid a low signal-to-noise ratio due to excessively low sound pressure signals.

[0042] Step 202: Determine the first solution equation and the second solution equation based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device, respectively.

[0043] In some embodiments, the aforementioned executing entity can determine the first and second solution equations based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device, respectively. The acoustic impedance solution model can be an acoustic model, mechanical model, or electrical model constructed based on the aforementioned material acoustic impedance measurement. In practice, the aforementioned acoustic impedance solution model can include at least one parameter selected from voltage parameters, sound pressure parameters, current parameters, acoustic parameters corresponding to the internal space of the material acoustic impedance measurement device, and relevant characteristic parameters corresponding to the loudspeaker. The first solution equation can be an equation whose parameters corresponding to the first signal group cannot be further expanded. The second solution equation can be an equation whose parameters corresponding to the second signal group cannot be further expanded.

[0044] As an example, the aforementioned executing entity can substitute the first signal group and the second signal group into the aforementioned acoustic impedance solution model to obtain the first solution equation and the second solution equation.

[0045] Step 203: Solve the acoustic impedance parameters for the first and second solution equations respectively to obtain the first and second solution acoustic impedances.

[0046] In some embodiments, the aforementioned executing entity can solve the acoustic resistance parameters of the first and second solving equations respectively to obtain the first and second solved acoustic resistances. The first solved acoustic resistance can characterize the total acoustic resistance at the capillary tube in the first state. The second solved acoustic resistance can characterize the total acoustic resistance at the capillary tube in the second state. The total acoustic resistance at the capillary tube is the sum of the acoustic resistance of the air column in the capillary tube and the material acoustic resistance (when the capillary tube outlet is covered with material). When the capillary tube outlet is not covered, the total acoustic resistance at the capillary tube is equal to the acoustic resistance of the air column in the capillary tube.

[0047] As an example, the aforementioned executing entity can perform multivariate parameter solutions on the first and second solving equations respectively to determine the first and second solving acoustic impedances.

[0048] Step 204: Determine the acoustic impedance of the measurement area of ​​the material to be measured based on the first and second solutions for acoustic impedance.

[0049] In some embodiments, the execution entity may determine the acoustic impedance of the measurement region of the material to be measured based on the first and second acoustic impedance solutions. The acoustic impedance of the measurement region characterizes the acoustic impedance corresponding to the measurement region included in the material to be measured.

[0050] As an example, when the first state can characterize that the outlet of the thin tube included in the material acoustic impedance measuring device is not covered, the execution entity can determine the difference between the second solved acoustic impedance and the first solved acoustic impedance as the acoustic impedance of the measurement area of ​​the material to be measured.

[0051] As another example, when the first state can also characterize that the outlet of the capillary tube included in the aforementioned material acoustic resistance measuring device is covered by a material with known characteristic acoustic resistance, firstly, the executing entity can determine the difference between the first solved acoustic resistance and the acoustic resistance of the area covered by the material with known characteristic acoustic resistance as the acoustic resistance of the capillary air column. Next, the difference between the second solved acoustic resistance and the acoustic resistance of the capillary air column is determined as the acoustic resistance of the measurement area.

[0052] The above-described embodiments of this disclosure have the following beneficial effects: the material acoustic impedance measurement method of some embodiments of this disclosure improves the accuracy of the acoustic impedance of the measurement area of ​​the material to be measured. Specifically, the reason for the low accuracy of characteristic acoustic impedance measurement is that the electrical characteristics of the circuit and the mechanical characteristics of the hardware used for characteristic acoustic impedance measurement often have a significant impact on the measurement of characteristic acoustic impedance. Ignoring the electrical and mechanical characteristics will lead to low accuracy of the measured characteristic acoustic impedance. Based on this, the material acoustic impedance measurement method of some embodiments of this disclosure firstly determines a first signal group in a first state and a second signal group in a second state of the material acoustic impedance measurement device. The first and second signal groups respectively include voltage signals, and the first and second signal groups respectively also include at least one of sound pressure signals and current signals. The voltage signal is the voltage signal of the loudspeaker included in the material acoustic impedance measurement device, the sound pressure signal is the sound pressure signal collected at the observation point position opposite to the loudspeaker in the material acoustic impedance measurement device, and the current signal is the current signal of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic impedance measurement device is covered by the measurement area of ​​the material to be measured. This is used to determine the different electrical and acoustic signals of the material acoustic impedance measuring device under a reference state (first state) and a state covering the material to be measured (second state). Next, based on the first signal group, the second signal group, and the acoustic impedance solution model corresponding to the material acoustic impedance measuring device, a first solution equation and a second solution equation are determined. The acoustic impedance solution model can be an acoustic model, mechanical model, or electrical model constructed based on the material acoustic impedance measuring device. Further, the acoustic impedance parameters are solved for the first and second solution equations to obtain the first and second solved acoustic impedances. This yields the acoustic impedance under the reference state (first solved acoustic impedance) and the acoustic impedance under the second state (second solved acoustic impedance). Finally, based on the first and second solved acoustic impedances, the acoustic impedance of the measurement area of ​​the material to be measured is determined. By using the acoustic impedance solution model constructed based on the acoustic, electrical, and mechanical characteristics of the material acoustic impedance measuring device, the acoustic impedance of the measurement area of ​​the material to be measured is thus measured with extremely high accuracy.

[0053] Further reference Figure 3 The diagram illustrates a flow 300 of another embodiment of the material acoustic impedance measurement method. Flow 300 of this material acoustic impedance measurement method includes the following steps:

[0054] Step 301: Determine the first signal group of the material acoustic impedance measuring device in the first state and the second signal group in the second state.

[0055] In some embodiments, the specific implementation of step 301 and its resulting technical effects can be found in [reference needed]. Figure 2Step 201 in the corresponding embodiment will not be repeated here.

[0056] Step 302: In response to determining that the first signal group includes a current signal and the second signal group includes a current signal, the ratio of the current signal and voltage signal included in the first signal group at each first frequency is substituted into the acoustic impedance solution model to obtain the first solution equation corresponding to each first frequency, and the ratio of the current signal and voltage signal included in the second signal group at each second frequency is substituted into the acoustic impedance solution model to obtain the second solution equation corresponding to each second frequency.

[0057] In some embodiments, the subject performing the material acoustic impedance measurement method (e.g. Figure 1 The computing device 101 shown can, in response to determining that a first signal group includes a current signal and a second signal group includes a current signal, substitute the ratio of the current signal and voltage signal included in the first signal group at each first frequency into the acoustic impedance solution model to obtain a first solution equation corresponding to each first frequency, and substitute the ratio of the current signal and voltage signal included in the second signal group at each second frequency into the acoustic impedance solution model to obtain a second solution equation corresponding to each second frequency. The first frequency and the second frequency may be the same or different.

[0058] In practice, frequency can be the angular frequency (ω) of the AC signal in the speaker coil included in the speaker. Frequency can also be the frequency (f) of the AC signal in the speaker coil included in the speaker.

[0059] As an example, firstly, the aforementioned execution entity can substitute the ratios of the current and voltage signals included in the first signal group at at least N different first frequencies into the acoustic impedance solution model to obtain the first solution equation corresponding to each first frequency. Then, the aforementioned execution entity can substitute the ratios of the current and voltage signals included in the second signal group at at least N different second frequencies into the acoustic impedance solution model to obtain the second solution equation corresponding to each second frequency. Correspondingly, the AC signal of the loudspeaker coil can be a narrow-band signal composed of at least N narrow-band signals of different frequencies, or it can be a wide-band signal covering the aforementioned N different frequencies. For example, the current signal included in the first signal group can be a narrow-band signal composed of at least N different narrow-band signals. Alternatively, the current signal included in the first signal group can be a wide-band signal covering at least N different frequencies. The value of N can be determined based on the number of parameters to be solved in the first and second solution equations.

[0060] In practice, the above acoustic impedance solution model can be expressed as follows:

[0061]

[0062] Where p represents the sound pressure signal. e represents the voltage signal. U represents the volumetric flow velocity generated when the loudspeaker emits sound. i represents the current signal. Za represents the total acoustic impedance of the cavity included in the material acoustic impedance measurement device, and is also the acoustic model constructed in the embodiments of this disclosure. u represents the equivalent velocity of the diaphragm included in the loudspeaker when it vibrates. S represents the effective vibrating area of ​​the diaphragm included in the loudspeaker. F represents the total Ampere force on the loudspeaker coil included in the loudspeaker. BL represents the product of the coil length and magnetic induction intensity of the loudspeaker coil included in the loudspeaker. ZE represents the mechanical model constructed in the embodiments of this disclosure. ZE represents the sum of the speaker's impedance, equivalent acoustic impedance, and equivalent mechanical impedance, and its reciprocal represents the electrical model constructed in the embodiments of this disclosure. ZM represents the sum of the speaker's mechanical impedance and equivalent acoustic impedance.

[0063] The total acoustic impedance Za can be characterized by the following expression (1):

[0064]

[0065] Where j represents the imaginary number sign. ω represents the angular frequency. Ca represents the acoustic compliance of the cavity. Ma represents the acoustic mass of the capillary tube. Ra represents the total acoustic resistance at the capillary tube.

[0066] The sum of the mechanical impedance and the equivalent acoustic impedance of the loudspeaker, ZM, can be characterized by the following expression (2):

[0067] ZM = Zm + S 2 *Za (2)

[0068] Where Zm represents the mechanical impedance of the loudspeaker. S represents the effective vibrating area of ​​the diaphragm included in the loudspeaker. Za represents the total acoustic impedance of the cavity of the loudspeaker characteristic parameter testing device. 2 *Za represents the equivalent acoustic impedance of the loudspeaker.

[0069] The mechanical impedance Zm can be characterized by the following expression (3):

[0070]

[0071] Where Rms represents the loudspeaker's mechanical damping. j represents the imaginary number. ω represents the angular frequency. Mms represents the loudspeaker's mechanical mass. Cms represents the loudspeaker's mechanical compliance.

[0072] The sum of the loudspeaker's impedance, equivalent acoustic impedance, and equivalent mechanical impedance, ZE, can be characterized by the following expression (4):

[0073]

[0074] Where Ze represents the electrical impedance of the loudspeaker. ZM represents the sum of the mechanical impedance and the equivalent acoustic impedance of the loudspeaker. BL represents the product of the length of the loudspeaker coil and the magnetic flux density. It represents the sum of the equivalent acoustic impedance and the equivalent mechanical impedance.

[0075] The impedance Ze of the loudspeaker can be characterized by the following expression (5):

[0076] Ze=Re+j*ω*Le (5)

[0077] Where Re represents the DC resistance of the speaker coil loop, including the loudspeaker coil. j represents the imaginary number. ω represents the angular frequency. Le represents the inductance of the speaker coil loop, including the loudspeaker coil.

[0078] Ra, Ma, Ca, Rms, Mms, CmS, Re, Le, BL, and S are the parameters that cannot be further expanded in the first and second solution equations.

[0079] In some optional implementations of certain embodiments, in response to determining that the first signal group includes a sound pressure signal and the second signal group includes a sound pressure signal, a first solution equation is determined based on the spectrum and acoustic impedance solution model corresponding to the voltage signal and sound pressure signal included in the first signal group, and a second solution equation is determined based on the spectrum and acoustic impedance solution model corresponding to the voltage signal and sound pressure signal included in the second signal group. Here, the spectrum is the representation of the time-domain signal in the frequency domain.

[0080] As an example, the aforementioned execution entity can determine the ratio of the spectra of the voltage signal and the sound pressure signal at multiple different frequencies, that is, determine... Spectrum

[0081] Step 303: Under the premise that the acoustic impedance solution model satisfies at least one of the target conditions in the target condition group, solve the acoustic impedance parameters of the first solution equation and the second solution equation respectively to obtain the first solution acoustic impedance and the second solution acoustic impedance.

[0082] In some embodiments, the execution entity may, provided that the acoustic impedance solution model satisfies at least one of the target conditions in the target condition set, solve the first solution equation and the second solution equation for acoustic impedance parameters, respectively, to obtain the first solved acoustic impedance and the second solved acoustic impedance. The target condition set includes: a first target condition and a second target condition. The first target condition is: the speaker parameters included in the acoustic impedance solution model for the speaker are fixed. The second target condition is: the acoustic parameters included in the acoustic impedance solution model for the internal space corresponding to the acoustic impedance measurement device are fixed.

[0083] Specifically, the first solution for acoustic resistance can be the value corresponding to the total acoustic resistance (Ra) at the capillary tube in the first solution equation. The second solution for acoustic resistance can be the value corresponding to the total acoustic resistance (Ra) at the capillary tube in the second solution equation.

[0084] In practice, the speaker parameters for the above-mentioned loudspeakers may include: basic parameters used to determine the speaker's T / S parameters, such as: loudspeaker mechanical damping (Rms), loudspeaker mechanical mass (Mms), loudspeaker mechanical compliance (Cms), DC resistance of the loudspeaker coil circuit (Re), loudspeaker coil circuit inductance (Le), the product of loudspeaker coil length and magnetic induction intensity (BL), and the effective vibrating area of ​​the loudspeaker diaphragm (S).

[0085] In practice, the acoustic parameters corresponding to the internal space of a material acoustic impedance measuring device may include: the structural acoustic parameters corresponding to the cavity included in the material acoustic impedance measuring device, and the structural acoustic parameters corresponding to the thin tube included in the material acoustic impedance measuring device.

[0086] For example, the structural acoustic parameter corresponding to a cavity can be cavity acoustic compliance (Ca). The structural acoustic parameter corresponding to a capillary tube can be capillary acoustic mass (Ma).

[0087] By solving the acoustic impedance parameters of the first and second solution equations respectively, under the premise that the acoustic impedance solution model satisfies at least one of the target conditions in the target condition set, the number of parameters to be solved in the first and second solution equations can be reduced, thereby improving the solution speed.

[0088] Specifically, when the acoustic parameters corresponding to the internal space of the material acoustic impedance measuring device have been theoretically calculated, solving the first and second equations for acoustic impedance parameters only requires solving for eight parameters: Ra, Rms, Mms, Cms, Re, Le, BL, and S. When the material acoustic impedance measuring device uses a loudspeaker with calibrated parameters, solving the first and second equations for acoustic impedance parameters only requires solving for three parameters: Ra, Ma, and Ca. When the acoustic parameters corresponding to the internal space of the material acoustic impedance measuring device have been theoretically calculated, and a loudspeaker with calibrated parameters is used, solving the first and second equations for acoustic impedance parameters only requires solving for one parameter: Ra.

[0089] Step 304: Determine the acoustic impedance of the measurement area of ​​the material to be measured based on the first and second solutions for acoustic impedance.

[0090] In some embodiments, the aforementioned execution entity may determine the acoustic impedance of the measurement area of ​​the material to be measured based on the first and second acoustic impedance solutions.

[0091] As an example, the aforementioned executing entity can determine the difference between the second and first solved acoustic impedances as the acoustic impedance of the measurement area.

[0092] Step 305: Determine the characteristic acoustic resistance of the material to be measured based on the acoustic resistance of the measurement area and the outlet area of ​​the capillary tube.

[0093] In some embodiments, the aforementioned executing entity can determine the characteristic acoustic resistance of the material to be measured based on the acoustic resistance of the measurement area and the outlet area of ​​the capillary tube. The characteristic acoustic resistance can be the acoustic resistance per unit area of ​​the material to be measured.

[0094] As an example, the aforementioned implementing entity can determine the characteristic acoustic impedance as the ratio of the acoustic impedance of the measurement area to the exit area.

[0095] As another example, firstly, the aforementioned executing entity can determine multiple measurement regions corresponding to the material to be measured. Then, the executing entity can determine the characteristic acoustic impedance corresponding to each of these multiple measurement regions. Finally, the obtained multiple characteristic acoustic impedances are weighted and averaged or arithmetically averaged to obtain the final characteristic acoustic impedance corresponding to the material to be measured. This method can eliminate random errors during sampling of the material to be measured, further improving the accuracy of the obtained characteristic acoustic impedance.

[0096] from Figure 3 It can be seen that, with Figure 2 Compared to the descriptions of some corresponding embodiments, this disclosure firstly adds constraints to the target condition set during the process of solving the acoustic impedance parameters of the first and second equations, thereby reducing the number of parameters to be solved in the equation parameter solving process and improving the solution speed. Furthermore, by combining current and voltage signals to solve for the characteristic acoustic impedance, there is no need to set up an additional signal acquisition device in the material acoustic impedance measurement device, thus reducing the cost of solving for the characteristic acoustic impedance.

[0097] Further reference Figure 4 The diagram illustrates a flow 400 of a further embodiment of a material acoustic impedance measurement method. Flow 400 of this material acoustic impedance measurement method includes the following steps:

[0098] Step 401: Determine the first signal group of the material acoustic impedance measuring device in the first state and the second signal group in the second state.

[0099] In some embodiments, the specific implementation of step 401 and its resulting technical effects can be found in [reference needed]. Figure 2 Step 201 in the corresponding embodiment will not be repeated here.

[0100] Step 402: In response to determining that the first signal group includes a current signal and a sound pressure signal, and the second signal group includes a current signal and a sound pressure signal, the following processing steps are performed:

[0101] Step 4021: Substitute the ratio of the current signal and voltage signal included in the first signal group at each third frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each third frequency.

[0102] In some embodiments, the execution entity may substitute the ratio of the current signal and voltage signal included in the first signal group at each third frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each third frequency.

[0103] Step 4022: Substitute the ratio of the voltage signal and sound pressure signal included in the first signal group at each fourth frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each fourth frequency.

[0104] In some embodiments, the execution entity may substitute the ratio of the voltage signal and the sound pressure signal included in the first signal group at each fourth frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each fourth frequency.

[0105] Step 4023: Substitute the ratio of the current signal and voltage signal included in the second signal group at each fifth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each fifth frequency.

[0106] In some embodiments, the execution entity may substitute the ratio of the current signal and voltage signal included in the second signal group at each fifth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each fifth frequency.

[0107] Step 4024: Substitute the ratio of the voltage signal and sound pressure signal included in the second signal group at each sixth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each sixth frequency.

[0108] In some embodiments, the execution entity may substitute the ratio of the voltage signal and the sound pressure signal included in the second signal group at each sixth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each sixth frequency.

[0109] In practice, the third and fifth frequencies can be the angular frequencies (ω) of the AC signal from the speaker coil included in the loudspeaker. Alternatively, the third and fifth frequencies can be the frequencies (f) of the AC signal from the speaker coil included in the loudspeaker. Specifically, the third, fourth, fifth, and sixth frequencies can be the same or different.

[0110] Step 403: Solve the acoustic impedance parameters for the first and second solution equations respectively to obtain the first and second solution acoustic impedances.

[0111] In some embodiments, the execution entity solves the acoustic impedance parameters for the first solution equation and the second solution equation respectively, to obtain the first solution acoustic impedance and the second solution acoustic impedance.

[0112] As an example, such as Figure 5 The flowchart shown illustrates the process of solving the acoustic impedance parameters for the first and second equations. The execution entity solves for the acoustic impedance parameters of the first and second equations respectively, obtaining the first and second solved acoustic impedances. This process may include the following steps:

[0113] Step 4031: Randomly generate the first initial solution array and the second initial solution array.

[0114] In some embodiments, the execution entity may randomly generate a first initial solution array and a second initial solution array. The first initial solution array may be the initial values ​​corresponding to the parameters to be solved in the first solution equation. The second initial solution array may be the initial values ​​corresponding to the parameters to be solved in the second solution equation. In practice, the first initial solution array and the second initial solution array may be the same or different.

[0115] Optionally, the aforementioned execution entity can generate one initial solution array, and use this initial solution array as both the first and second initial solution arrays. This reduces the number of times arrays are randomly generated, thereby optimizing the acoustic impedance solution process and further improving the speed of acoustic impedance solution.

[0116] Optionally, the deviation between the first initial solution array and the second initial solution array is less than or equal to a preset deviation.

[0117] Specifically, the generation of the initial solution array is random. To ensure the effectiveness of the generated initial solution array, the initial solution array with large deviations can be discarded, and only the initial solution array with small deviations can be retained. This avoids the initial solution array with large deviations affecting the generation speed and parameter accuracy of the final generated first and second acoustic impedances.

[0118] Step 4032: Based on the first initial solution array, solve the acoustic impedance parameters of the first solution equation corresponding to each third frequency to obtain the first reference solution array.

[0119] In some embodiments, the execution entity can solve for the acoustic impedance parameters of the first solution equation corresponding to each third frequency based on the first initial solution array to obtain a first reference solution array. Specifically, the execution entity can use the first initial solution array as the initial value of the parameter to be solved in the first solution equation corresponding to each third frequency, and solve for the parameter of the first solution equation corresponding to each third frequency to determine the first reference solution array.

[0120] In some optional implementations of certain embodiments, the aforementioned execution entity can, under the condition of parameter constraints on the parameters to be solved for the first solution equations corresponding to each third frequency, solve for the acoustic impedance parameters based on the first initial solution array to obtain a first reference solution array. In practice, by adding constraints to the parameters to be solved, for example, within a range of ±20% of the values, the solution speed and accuracy of the first reference solution array can be significantly improved.

[0121] Step 4033: Based on the first reference solution array, solve the acoustic impedance parameters of the first solution equation corresponding to each fourth frequency to obtain the first solution acoustic impedance.

[0122] In some embodiments, the execution entity can solve for the acoustic impedance parameters of the first solution equation corresponding to each fourth frequency based on the first reference solution array to obtain the first solved acoustic impedance. Specifically, the execution entity can use the first reference solution array as the initial value of the parameter to be solved in the first solution equation corresponding to each fourth frequency, and solve for the parameter of the first solution equation corresponding to each fourth frequency to obtain the first solved acoustic impedance.

[0123] In some optional implementations of certain embodiments, the aforementioned execution entity can, under the condition of parameter constraints on the parameters to be solved for the first solution equation corresponding to each fourth frequency, solve the acoustic impedance parameters according to the first reference solution array to obtain the first solved acoustic impedance. In practice, by adding constraints to the parameters to be solved, for example, within a range of ±20% of the values, the solution speed and accuracy of the first solved acoustic impedance can be significantly improved.

[0124] Step 4034: Based on the second initial solution array, solve the acoustic impedance parameters of the second solution equations corresponding to each fifth frequency to obtain the second reference solution array.

[0125] In some embodiments, the execution entity can solve for the acoustic impedance parameters of the second solution equations corresponding to each fifth frequency based on the second initial solution array to obtain a second reference solution array. Specifically, the execution entity can use the second initial solution array as the initial values ​​of the parameters to be solved in the second solution equations corresponding to each fifth frequency to solve for the parameters and determine the second reference solution array.

[0126] In some optional implementations of certain embodiments, the aforementioned execution entity can, under the condition of parameter constraints on the parameters to be solved for the second solution equations corresponding to each fifth frequency, solve for the acoustic impedance parameters based on the second initial solution array to obtain a second reference solution array. In practice, by adding constraints to the parameters to be solved, for example, within a range of ±20% of the values, the solution speed and accuracy of the second reference solution array can be significantly improved.

[0127] Step 4035: Based on the second reference solution array, solve the acoustic impedance parameters of the second solution equation corresponding to each sixth frequency to obtain the second solution acoustic impedance.

[0128] In some embodiments, the execution entity can solve for the acoustic impedance parameters of the second solution equation corresponding to each sixth frequency based on the second reference solution array to obtain the second solved acoustic impedance. Specifically, the execution entity can use the second reference solution array as the initial value of the parameter to be solved in the second solution equation corresponding to each sixth frequency, and solve for the parameter of the second solution equation corresponding to each sixth frequency to obtain the second solved acoustic impedance.

[0129] In some optional implementations of certain embodiments, the aforementioned execution entity can, under the condition of parameter constraints on the parameters to be solved for the second solution equations corresponding to each sixth frequency, solve for the acoustic impedance parameters according to the second reference solution array to obtain the second solved acoustic impedance. In practice, by adding constraints to the parameters to be solved, for example, within a range of ±20% of the values, the solution speed and accuracy of the second solved acoustic impedance can be significantly improved.

[0130] In some optional implementations of certain embodiments, the execution entity may use steps 4032 and 4033 as a first step group, and steps 4034 and 4035 as a second step group. Then, the first and second step groups are executed in parallel to further improve the acoustic impedance solution speed.

[0131] Step 404: Determine the acoustic impedance of the measurement area of ​​the material to be measured based on the first and second solutions for acoustic impedance.

[0132] In some embodiments, the specific implementation of step 404 and its resulting technical effects can be found in [reference needed]. Figure 2 Step 204 in the corresponding embodiment can also be referred to Figure 3 Step 304 in the corresponding embodiment will not be repeated here.

[0133] from Figure 4 It can be seen that, with Figure 2 Compared with the description of some corresponding embodiments, and with Figure 3 Compared to some corresponding embodiments, the accuracy of the acoustic impedance of the measurement area obtained based on voltage and current signals (i.e., only based on the electrical model constructed in the embodiments of this disclosure) is often lower than the accuracy obtained based on voltage and sound pressure signals. Therefore, this disclosure first determines a reference solution array based on voltage and current signals. Since the result of the reference solution array is extremely close to the actual total acoustic impedance at the capillary tube, the total acoustic impedance at the capillary tube is solved by combining voltage and sound pressure signals on the basis of the reference solution array, which greatly improves the solution speed while still ensuring that the final acoustic impedance of the measurement area is the most accurate result obtained through the acoustic, mechanical, and electrical acoustic impedance solution model.

[0134] Further reference Figure 6 As an implementation of the methods shown in the above figures, this disclosure provides some embodiments of a material acoustic impedance measurement device, which are similar to... Figure 2 Corresponding to the method embodiments shown, this material acoustic impedance measurement device can be specifically applied to various electronic devices.

[0135] like Figure 6 As shown, some embodiments of a material acoustic impedance measurement device include: a cavity 1, a loudspeaker 2, a thin tube 3, a material 4 to be measured for acoustic impedance, and an observation point position 5 opposite to the loudspeaker 2. The loudspeaker 2 is located on the first side of the cavity 1, with its sound direction facing the interior of the cavity 1. The thin tube 3 is located on the second side of the cavity 1 and communicates with the cavity 1. The measurement area of ​​the material 4 to be measured is sealed over the outlet of the thin tube 3. The material 4 is the material whose acoustic impedance is to be determined by the acoustic impedance solution model corresponding to the material acoustic impedance measurement device. In practice, when the material 4 to be measured is sealed over the thin tube 3, the outlet boundary of the thin tube 3 coincides with the boundary of the measurement area of ​​the material 4 to be measured, and the material portion outside the measurement area is confined to the side of the thin tube 3 to fix the material 4 to be measured.

[0136] Optionally, the first side of the cavity 1 may further include an opening for mounting the speaker 2. Furthermore, the acoustic impedance measuring device may further include a sealing element (not shown in the figure). The sealing element is disposed between the speaker 2 and the opening to ensure the airtightness of the acoustic impedance measuring device.

[0137] Alternatively, the speaker 2 may also be placed inside the cavity 1.

[0138] Optionally, the aforementioned material acoustic impedance measurement device may further include a microphone unit (not shown in the figure). The microphone unit is located inside the cavity 1 at the observation point 5 corresponding to the speaker 2. In practice, the microphone unit can be used to collect sound pressure signals.

[0139] By using the aforementioned acoustic impedance measurement device and the corresponding acoustic impedance solution model, the acoustic impedance of the measurement area can be determined quickly and accurately.

[0140] It is understandable that the units described in the material acoustic impedance measuring device 600 are the same as the reference. Figure 2 The steps in the described method correspond accordingly. Therefore, the operations, features, and beneficial effects described above for the method also apply to the material acoustic impedance measuring device 600 and the units contained therein, and will not be repeated here.

[0141] The following is for reference. Figure 7 It illustrates electronic devices suitable for implementing some embodiments of the present disclosure (such as...). Figure 1 The diagram shows the structure of the computing device 101)700. Figure 7 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this disclosure.

[0142] like Figure 7 As shown, the electronic device 700 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory 702 or a program loaded from a storage device 708 into a random access memory 703. The random access memory 703 also stores various programs and data required for the operation of the electronic device 700. The processing unit 701, the read-only memory 702, and the random access memory 703 are interconnected via a bus 704. An input / output interface 705 is also connected to the bus 704.

[0143] Typically, the following devices can be connected to I / O interface 705: input devices 706 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 707 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 708 including, for example, magnetic tapes, hard disks, etc.; and communication devices 709. Communication device 709 allows electronic device 700 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 7 An electronic device 700 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 7 Each box shown can represent a device or multiple devices as needed.

[0144] In particular, according to some embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, some embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 709, or installed from a storage device 708, or installed from a read-only memory 702. When the computer program is executed by the processing device 701, it performs the functions defined in the methods of some embodiments of this disclosure.

[0145] It should be noted that, in some embodiments of this disclosure, the computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In some embodiments of this disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In some embodiments of this disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0146] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol such as HTTP (Hypertext Transfer Protocol) and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and end-to-end networks (e.g., ad hoc end-to-end networks), as well as any currently known or future-developed networks.

[0147] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more programs that, when executed by the electronic device, cause the electronic device to: determine a first signal group in a first state and a second signal group in a second state of the material acoustic impedance measuring device, wherein the first and second signal groups respectively include voltage signals, and the first and second signal groups respectively further include at least one of a sound pressure signal and a current signal, wherein the voltage signal is the voltage signal of the loudspeaker included in the material acoustic impedance measuring device, and the sound pressure signal is the observation point position in the material acoustic impedance measuring device opposite to the loudspeaker. The acquired sound pressure signal and the current signal are the current signals of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic impedance measuring device is covered by the measurement area of ​​the material to be measured. Based on the first signal group, the second signal group, and the acoustic impedance solution model corresponding to the material acoustic impedance measuring device, the first solution equation and the second solution equation are determined respectively. The acoustic impedance parameters are solved for the first solution equation and the second solution equation respectively to obtain the first solution acoustic impedance and the second solution acoustic impedance. Based on the first solution acoustic impedance and the second solution acoustic impedance, the acoustic impedance of the measurement area of ​​the material to be measured is determined.

[0148] Computer program code for performing operations of some embodiments of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0149] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0150] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0151] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A method for measuring the acoustic impedance of a material, comprising: A first signal group and a second signal group in a second state are respectively determined for the material acoustic impedance measuring device in a first state. The first signal group and the second signal group each include a voltage signal. The first signal group and the second signal group each also include at least one of a sound pressure signal and a current signal. The voltage signal is the voltage signal of the loudspeaker included in the material acoustic impedance measuring device. The sound pressure signal is the sound pressure signal collected at the observation point position opposite to the loudspeaker in the material acoustic impedance measuring device. The current signal is the current signal of the loudspeaker. The second state indicates that the outlet of the thin tube included in the material acoustic impedance measuring device is covered by the measurement area of ​​the material to be measured. Based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device, the first solution equation and the second solution equation are determined respectively, wherein the acoustic impedance solution model is as follows: in, Indicates sound pressure signal, Indicates voltage signal, This indicates the volumetric flow velocity produced when a loudspeaker emits sound. Represents a current signal. This represents the total acoustic impedance of the cavities included in the material acoustic impedance measurement device, and is also the acoustic model that has been constructed. This indicates the equivalent velocity of the diaphragm in the loudspeaker when it vibrates. This indicates the effective vibrating area of ​​the diaphragm included in the loudspeaker. This indicates the total Ampere force experienced by the speaker coil, including the speaker. This represents the product of the length of the speaker coil and the magnetic flux density of the speaker. This represents the mechanical model constructed according to the embodiments of this disclosure. This represents the sum of the loudspeaker's electrical impedance, equivalent acoustic impedance, and equivalent mechanical impedance; its reciprocal represents the constructed electrical model. This represents the sum of the loudspeaker's mechanical impedance and equivalent acoustic impedance. The acoustic impedance parameters are solved by solving the first and second solution equations respectively, to obtain the first and second solution acoustic impedances. Based on the first and second solutions for acoustic impedance, the acoustic impedance of the measurement area of ​​the material to be measured is determined.

2. The method according to claim 1, wherein, The step of solving the acoustic impedance parameters of the first and second equations respectively to obtain the first and second acoustic impedances includes: Provided that the acoustic impedance solution model satisfies at least one of the target conditions in the target condition set, the acoustic impedance parameters are solved for the first solution equation and the second solution equation respectively to obtain the first solution acoustic impedance and the second solution acoustic impedance. The target condition set includes: a first target condition and a second target condition. The first target condition is that the loudspeaker parameters included in the acoustic impedance solution model for the loudspeaker are fixed. The second target condition is that the acoustic parameters included in the acoustic impedance solution model for the internal space corresponding to the acoustic impedance measurement device of the material are fixed.

3. The method according to claim 1, wherein, The method further includes: The characteristic acoustic resistance of the material to be measured is determined based on the acoustic resistance of the measurement area and the outlet area of ​​the thin tube.

4. The method according to claim 1, wherein, The step of determining the first solution equation and the second solution equation based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device, respectively, includes: In response to determining that the first signal group includes a current signal and the second signal group includes a current signal, the ratio of the current signal and voltage signal included in the first signal group at each first frequency is substituted into the acoustic impedance solution model to obtain the first solution equation corresponding to each first frequency, and the ratio of the current signal and voltage signal included in the second signal group at each second frequency is substituted into the acoustic impedance solution model to obtain the second solution equation corresponding to each second frequency.

5. The method according to claim 1, wherein, The step of determining the first solution equation and the second solution equation based on the acoustic impedance solution models corresponding to the first signal group, the second signal group, and the material acoustic impedance measurement device, respectively, includes: In response to determining that the first signal group includes a current signal and a sound pressure signal, and that the second signal group includes a current signal and a sound pressure signal, the following processing steps are performed: Substitute the ratio of the current signal and voltage signal included in the first signal group at each third frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each third frequency; Substitute the ratio of the voltage signal and the sound pressure signal included in the first signal group at each fourth frequency into the acoustic impedance solution model to obtain the first solution equation corresponding to each fourth frequency; Substitute the ratio of the current signal and voltage signal included in the second signal group at each fifth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each fifth frequency; Substitute the ratio of the voltage signal and the sound pressure signal included in the second signal group at each sixth frequency into the acoustic impedance solution model to obtain the second solution equation corresponding to each sixth frequency.

6. The method according to claim 5, wherein, The step of solving the acoustic impedance parameters of the first and second equations respectively to obtain the first and second acoustic impedances includes: Randomly generate a first initial solution array and a second initial solution array; Based on the first initial solution array, the acoustic impedance parameters are solved for the first solution equations corresponding to each third frequency to obtain the first reference solution array; Based on the first reference solution array, the acoustic impedance parameters of the first solution equation corresponding to each fourth frequency are solved to obtain the first solution acoustic impedance. Based on the second initial solution array, the acoustic impedance parameters of the second solution equations corresponding to each fifth frequency are solved to obtain the second reference solution array; Based on the second reference solution array, the acoustic impedance parameters are solved for the second solution equation corresponding to each sixth frequency to obtain the second solution acoustic impedance.

7. An electronic device, comprising: One or more processors; A storage device on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1 to 6.

8. A computer-readable medium having a computer program stored thereon, wherein, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

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