Method and device for evaluating crosstalk of audio circuit of whole machine

Abstract

The application discloses a whole machine audio circuit crosstalk evaluation method and device, wherein the method comprises the following steps: playing a preset step and linear sweep frequency sound source through a whole machine load, and obtaining a crosstalk sound recording through local microphone collection; disconnecting the audio load, playing a preset sweep frequency sound source with a known sound size, and obtaining a sweep frequency pickup recording through local microphone collection; comparing the crosstalk sound recording and the sweep frequency pickup recording, and obtaining a whole machine audio circuit crosstalk evaluation result through corresponding post-processing. Through the above method, the crosstalk index of the circuit can be objectively and accurately evaluated, and the quantitative evaluation of the influence of the whole machine can be carried out. The application provides an accurate judgment basis for the audio loop crosstalk index.

Description

Technical Field

[0001] This application relates to the technical field, and in particular to a method and apparatus for evaluating crosstalk in the audio circuit of a complete machine. Background Technology

[0002] Currently, there are three methods for evaluating crosstalk in the audio circuit of a complete device: 1) The speaker is replaced by an RC circuit consisting of a cement resistor load or a cement resistor with a series capacitor; 2) The microphone is short-circuited or open-circuited to avoid ambient sound being picked up by the microphone; 3) The device is operated under low load and maximum load respectively, and the background noise of the microphone circuit is recorded and compared.

[0003] However, current methods all have some drawbacks, such as: 1) Inaccurate load equivalence, the load equivalence method does not match the actual load, resulting in inaccuracy with the actual scenario; 2) To avoid ambient sound being picked up by the microphone, the microphone short circuit and open circuit used are also quite different from the actual circuit. For example, short circuit and open circuit will affect the amplification factor of the microphone circuit and will also cause crosstalk in other paths; 3) After recording the background noise of the microphone ADC, it can only see whether there is crosstalk, but cannot effectively quantize and provide a basis for quantization judgment. Summary of the Invention

[0004] This application provides a method and apparatus for evaluating crosstalk in the audio circuit of a complete machine, in order to solve the problems of inaccurate crosstalk evaluation and inability to functionally quantify crosstalk indicators in the prior art.

[0005] To address the aforementioned technical problems, this application proposes a method for evaluating crosstalk in the audio circuit of a complete device, comprising: playing preset step and linear sweep frequency sources under the load of the complete device, and acquiring crosstalk sound recordings through the device's microphone; disconnecting the audio load, playing a sweep frequency source with a preset known volume, and acquiring sweep frequency pickup recordings through the device's microphone; comparing the crosstalk sound recordings and the sweep frequency pickup recordings, and performing appropriate post-processing to obtain the evaluation result of crosstalk in the audio circuit of the complete device.

[0006] Optionally, by comparing the crosstalk recording and the sweep frequency pickup recording, and after appropriate post-processing, the evaluation results of the crosstalk of the whole audio circuit are obtained, including: performing FFT transformation on the crosstalk recording and the sweep frequency pickup recording to obtain the amplitude difference between crosstalk and pickup at each frequency point, thereby obtaining the relative weight of crosstalk to pickup; and calculating the SNR index based on the relative weight of crosstalk to pickup.

[0007] Optionally, by comparing the crosstalk recording and the frequency sweep recording, and after appropriate post-processing, the evaluation results of the crosstalk of the whole audio circuit are obtained, including: performing frequency response and harmonic analysis on the crosstalk recording to obtain the distortion ratio of the fundamental frequency and harmonics of the crosstalk, wherein the distortion ratio of the harmonics belongs to the nonlinear part.

[0008] Optionally, the evaluation method for crosstalk in the audio circuit of the whole machine also includes: isolating the acoustic load of the speaker separately, using the microphone circuit and microphone of the whole machine for sound pickup, and placing the audio circuit of the DUT in an environment with a noise floor lower than the operating noise of the whole machine.

[0009] Optionally, disconnect the audio load and play a frequency sweep sound source with a preset known volume, including: using the same speaker or artificial mouth with a flat playback frequency response to emit a frequency sweep sound source calibrated at 74dB SPL at the microphone position of the DUT.

[0010] To address the aforementioned technical problems, this application proposes an evaluation device for crosstalk in the audio circuit of a complete device, comprising: a main body; a microphone and its microphone circuit for sound acquisition; and a processing unit including a crosstalk recording module, a sweep frequency pickup recording module, and an evaluation result module. The crosstalk recording module is used to play preset step and linear sweep frequency sound sources through the device's load and acquire crosstalk recordings through the device's microphone. The sweep frequency pickup recording module is used to disconnect the audio load, play a sweep frequency sound source with a preset known volume, and acquire sweep frequency pickup recordings through the device's microphone. The evaluation result module is used to compare the crosstalk recordings and the sweep frequency pickup recordings, and after appropriate post-processing, obtain the evaluation result for the crosstalk in the audio circuit of the complete device.

[0011] Optionally, the evaluation results module is also used to: perform FFT conversion on crosstalk recordings and frequency sweep recordings to obtain the amplitude difference between crosstalk and sound pickup at each frequency point, thereby obtaining the relative weight of crosstalk to sound pickup; and calculate the SNR index based on the relative weight of crosstalk to sound pickup.

[0012] Optionally, the evaluation results module is also used to: perform frequency response and harmonic analysis on the crosstalk recording to obtain the distortion ratio of the fundamental frequency and harmonics of the crosstalk, wherein the distortion ratio of the harmonics belongs to the nonlinear part.

[0013] Optionally, the acoustic load of the speaker is isolated separately; the audio circuitry of the DUT is placed in an environment with a noise floor lower than the overall operating noise of the machine.

[0014] Optionally, the sweep frequency pickup and recording module is also used to: emit a sweep frequency sound source calibrated at 74dB SPL at the microphone position of the DUT using the same speaker or artificial mouth with flat playback frequency response.

[0015] This application proposes a method and apparatus for evaluating crosstalk in the audio circuit of a complete device. The method includes: playing preset stepped and linear sweep frequency audio sources under the load of the complete device, and acquiring crosstalk sound recordings through the device's microphone; disconnecting the audio load, playing a preset sweep frequency audio source with a known volume, and acquiring sweep frequency audio recordings through the device's microphone; comparing the crosstalk sound recordings and the sweep frequency audio recordings, and performing appropriate post-processing to obtain the evaluation result of the crosstalk in the audio circuit of the complete device. Through the above method, this application can objectively and accurately evaluate the crosstalk index of the circuit and perform a quantitative evaluation of its impact on the complete device. It provides an accurate basis for judging the crosstalk index of the audio circuit to be qualified. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating an embodiment of the method for evaluating crosstalk in the audio circuit of this application.

[0018] Figure 2 This is a schematic diagram of an embodiment of the evaluation device for crosstalk in the overall audio circuit of this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of this application, the evaluation method and apparatus for crosstalk of the whole-machine audio circuit provided in this application are further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The test procedure for crosstalk in the overall audio circuit requires testing two operating states of the audio circuit. Specifically: State 1: The audio circuit operates at rated power – the microphone collects the background noise. State 2: The audio circuit operates at minimum power (minimum interference) – the microphone collects the background noise. By comparing the background noise collected by the microphone pickup circuit in State 1 and State 2, the circuit's background noise value is determined, and the amount of crosstalk in the circuit is identified.

[0021] Existing testing solutions for complete audio circuits:

[0022] 1. When the audio circuit of the whole machine is under maximum load, if the load is a speaker, the sound emitted under maximum load is relatively loud. At this time, the sound picked up by the microphone loop includes not only circuit crosstalk, but also the sound of the speaker. It is impossible to separate the crosstalk sound separately.

[0023] 2. In order to isolate the crosstalk of the circuit, the existing solutions generally use the method of short-circuiting or disconnecting the microphone to remove the sound emitted by the speaker in the space.

[0024] 3. By comparing the background noise of the microphone pickup circuit in State 1 and State 2, it is impossible to determine or rule out that State 1 is a clean and crosstalk-free state. On the other hand, the background noise in State 2 has crosstalk. It is impossible to give a reasonable and accurate judgment on the magnitude of this crosstalk. It can only be said that State 2 is not as good as State 1, but it is impossible to determine how much the SNR has decreased.

[0025] Based on this, please refer to the solution proposed in this application. Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the method for evaluating crosstalk in the audio circuit of the entire device according to this application. In this embodiment, the method for evaluating crosstalk in the audio circuit of the entire device may include steps S110 to S130, and the specific steps are as follows:

[0026] S110: Plays preset step and linear sweep audio sources under full load, and obtains crosstalk recordings through the microphone of the unit.

[0027] Crosstalk assessment is based on the existing load of the whole circuit, that is, using the load of the whole machine, such as using the same load as the whole machine, such as the same model of speaker, speaker cavity, and mounted on the same structural housing.

[0028] To isolate crosstalk from the original microphone circuit and microphone used for sound pickup, the acoustic load of the speaker needs to be isolated separately. Therefore, the acoustic load (speaker, speaker cavity, playback part of the whole machine) can be run to a soundproof box or another room (such as a reverberation room) through a low impedance speaker cable. The audio circuit of the DUT is placed in an environment with a noise floor much lower than the operating noise of the whole machine (such as an anechoic chamber with a noise floor of only 20dBA). At this time, the microphone circuit and microphone only record the crosstalk generated by the DUT.

[0029] The entire device is loaded with a stepped + linear sweep audio source (specified). This covers all frequency bands of the device's operation. Furthermore, the signals collected by the microphone circuit and microphone loop allow for easy identification of any spectral signals consistent with the playback signal, accurately determining the presence of crosstalk. This collected signal is then used for further quantitative analysis. The recorded sound is labeled "Crosstalk Recording".

[0030] S120: Disconnect the audio load, play a frequency sweep sound source with a preset known volume, and obtain frequency sweep sound recording through the local microphone.

[0031] Inside the anechoic chamber, disconnect the audio load. Using a speaker or a mouthpiece with a flat frequency response, emit a swept-frequency sound source calibrated at 74 dB SPL (i.e., -20 dB Pa) at the microphone position of the DUT (the sound source is the same as above, using a stepped + linear sweep sound source; the playback volume needs to be set to a known value, not necessarily 74 dB SPL, to ensure that the captured sound does not have clipping). The recorded sound is then labeled "sweep-frequency pickup recording".

[0032] S130: By comparing crosstalk recordings and sweep frequency pickup recordings, and after appropriate post-processing, the evaluation results of crosstalk in the overall audio circuit are obtained.

[0033] Optionally, by comparing the crosstalk recordings and the swept-frequency pickup recordings, and after appropriate post-processing, an evaluation result of the crosstalk in the overall audio circuit is obtained, including:

[0034] 1) Perform FFT conversion on the crosstalk recording and the sweep frequency pickup recording to obtain the amplitude difference between crosstalk and pickup at each frequency point, thereby obtaining the relative weight of crosstalk to pickup; calculate the SNR index based on the relative weight of crosstalk to pickup.

[0035] 2) Frequency response and harmonic analysis were performed on the crosstalk recordings to determine the distortion ratio of the fundamental frequency to the harmonics. The harmonic distortion ratio is a non-linear component. The harmonic distortion ratio is a part that current linear echo cancellation algorithms cannot eliminate, which will affect the overall echo cancellation performance of the device.

[0036] Through the above methods, this embodiment can accurately separate the crosstalk amount. To accurately assess crosstalk, a specified audio source is used to facilitate determining the coherence between the recording and the audio source, and to accurately determine whether crosstalk exists in the audio circuit. To assess the relative value of the crosstalk amount, a reference recording, namely "frequency sweep recording," is added to obtain the equivalent pickup noise of the crosstalk, thereby obtaining the SNR index. To further evaluate the impact of "crosstalk recording," a frequency response and harmonic analysis of the "crosstalk recording" is proposed to obtain the ratio of the fundamental frequency to the harmonics + distortion of the crosstalk, which is used to further determine the nonlinearity of the crosstalk.

[0037] Based on the above-described method for evaluating crosstalk in the overall audio circuit, this application also proposes an apparatus for evaluating crosstalk in the overall audio circuit. Please refer to [link to relevant documentation]. Figure 2 , Figure 2 This is a schematic diagram of an embodiment of the evaluation apparatus for crosstalk in the audio circuit of the present application. In this embodiment, the evaluation apparatus 200 for crosstalk in the audio circuit of the entire device may include:

[0038] fuselage body 210;

[0039] A microphone and its microphone circuit 220 are used for sound acquisition;

[0040] The processing unit 230 includes a crosstalk recording module 231, a frequency sweep pickup recording module 232, and an evaluation result module 233.

[0041] Among them, the crosstalk recording module 231 is used to play preset step and linear sweep frequency sound sources through the whole machine load, and obtain crosstalk recording through the microphone of the machine.

[0042] The frequency sweep pickup and recording module 232 is used to disconnect the audio load, play a frequency sweep sound source with a preset known volume, and acquire the frequency sweep pickup and recording through the local microphone;

[0043] The evaluation result module 233 is used to compare crosstalk recordings and sweep frequency pickup recordings, and after corresponding post-processing, to obtain the evaluation result of crosstalk in the whole device's audio circuit.

[0044] Optionally, the evaluation result module 233 is also used to: perform FFT conversion on the crosstalk recording and the sweep frequency pickup recording to obtain the amplitude difference between crosstalk and pickup at each frequency point, thereby obtaining the relative weight of crosstalk to pickup; and calculate the SNR index based on the relative weight of crosstalk to pickup.

[0045] Optionally, the evaluation result module 233 is also used to: perform frequency response and harmonic analysis on the crosstalk recording to obtain the distortion ratio of the fundamental frequency and harmonics of the crosstalk, wherein the distortion ratio of the harmonics belongs to the nonlinear part.

[0046] Optionally, the acoustic load of the speaker is isolated separately; the audio circuitry of the DUT is placed in an environment with a noise floor lower than the overall operating noise of the machine.

[0047] Optionally, the sweep frequency pickup and recording module 232 is also used to: emit a sweep frequency sound source calibrated at 74dB SPL at the microphone position of the DUT using the same speaker or artificial mouth with flat playback frequency response.

[0048] In summary, the load in this application adopts the final load of the entire device, consistent with the actual working scenario; the microphone adopts a microphone from the actual working scenario, consistent with the working state of the actual microphone circuit. This solves the problem of ambient sound being picked up by the microphone; a specific playback sound source is used to intuitively determine whether crosstalk exists in the circuit, introducing a new reference quantity, and combining it with the crosstalk noise floor, the crosstalk is quantified and post-processed, providing a quantitative basis for judging whether the circuit performance indicators are qualified.

[0049] It is understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, for ease of description, the accompanying drawings show only the parts relevant to this application, not all structures. The step numbers used herein are also for convenience of description and are not intended to limit the order in which the steps are performed. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0050] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0051] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0052] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for evaluating crosstalk in the audio circuit of a complete device, characterized in that, include: By controlling the overall load, preset step and linear sweep frequency sources are played, and crosstalk recordings are obtained by capturing them through the microphone of the machine. Disconnect the audio load, play a frequency sweep sound source with a preset known volume, and capture the frequency sweep sound recording through the local microphone; By comparing the crosstalk recording and the frequency sweep recording, and after appropriate post-processing, the evaluation result of the crosstalk of the whole device's audio circuit is obtained.

2. The method for evaluating crosstalk in the overall audio circuit according to claim 1, characterized in that, The comparison of the crosstalk recording and the frequency sweep recording, followed by appropriate post-processing, yields an evaluation result of the crosstalk in the overall audio circuit, including: The crosstalk recording and the frequency sweep recording are subjected to FFT conversion to obtain the amplitude difference between crosstalk and sound pickup at each frequency point, thereby obtaining the relative weight of crosstalk to sound pickup. The SNR index is calculated based on the ratio of crosstalk to the pickup volume.

3. The method for evaluating crosstalk in the overall audio circuit according to claim 1, characterized in that, The comparison of the crosstalk recording and the frequency sweep recording, followed by appropriate post-processing, yields an evaluation result of the crosstalk in the overall audio circuit, including: Frequency response and harmonic analysis are performed on the crosstalk recording to obtain the distortion ratio of the fundamental frequency and harmonics of the crosstalk, wherein the distortion ratio of the harmonics belongs to the nonlinear part.

4. The method for evaluating crosstalk in the overall audio circuit according to claim 1, characterized in that, Also includes: The speaker's acoustic load is isolated separately, and the microphone circuit and microphone of the whole machine are used for sound pickup. The audio circuit of the DUT is placed in an environment with a lower background noise than the overall machine's operating noise.

5. The method for evaluating crosstalk in the overall audio circuit according to claim 1, characterized in that, The step of disconnecting the audio load and playing a frequency sweep sound source with a preset known volume includes: Using the same speaker or artificial mouth with a flat playback frequency response, a swept frequency source calibrated to 74dB SPL is emitted from the microphone position of the DUT.

6. An evaluation device for crosstalk in the audio circuit of a complete machine, characterized in that, include: The fuselage itself; A microphone and its microphone circuitry are used for sound acquisition. The processing unit includes a crosstalk recording module, a frequency sweep recording module, and an evaluation result module; The crosstalk recording module is used to play preset step and linear sweep frequency sound sources through the load of the whole machine, and to obtain crosstalk recordings through the microphone of the machine. The frequency sweep pickup and recording module is used to disconnect the audio load, play a frequency sweep sound source with a preset known volume, and obtain frequency sweep pickup and recording through the local microphone; The evaluation result module is used to compare the crosstalk recording and the frequency sweep recording, and after corresponding post-processing, to obtain the evaluation result of the crosstalk of the whole audio circuit.

7. The evaluation device for crosstalk in the audio circuit of the whole machine according to claim 6, characterized in that, The evaluation result module is also used for: The crosstalk recording and the frequency sweep recording are subjected to FFT conversion to obtain the amplitude difference between crosstalk and sound pickup at each frequency point, thereby obtaining the relative weight of crosstalk to sound pickup. The SNR index is calculated based on the ratio of crosstalk to the pickup volume.

8. The evaluation device for crosstalk in the audio circuit of a complete machine according to claim 6, characterized in that, The evaluation result module is also used for: Frequency response and harmonic analysis are performed on the crosstalk recording to obtain the distortion ratio of the fundamental frequency and harmonics of the crosstalk, wherein the distortion ratio of the harmonics belongs to the nonlinear part.

9. The evaluation device for crosstalk in the audio circuit of a complete machine according to claim 6, characterized in that, The acoustic load of the loudspeaker is isolated separately; The audio circuitry of the DUT is placed in an environment where the background noise is lower than the overall operating noise of the machine.

10. The evaluation device for crosstalk in the audio circuit of a complete machine according to claim 6, characterized in that, The frequency sweep pickup and recording module is also used for: Using the same speaker or artificial mouth with a flat playback frequency response, a swept frequency source calibrated to 74dB SPL is emitted from the microphone position of the DUT.

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