A volume control system and method for a car audio player

Abstract

This application provides a volume adjustment control system and method for an in-vehicle player, applied in the field of in-vehicle audio processing technology. It acquires multiple audio source signals and identifies the source type, priority, and spectral characteristics of each signal, providing a basis for subsequent differentiated processing. It analyzes the sound pressure level and spectral distribution of ambient noise to compensate for subsequent volume adjustments, ensuring that important information can still be heard in a noisy environment. By establishing a sound field model and calculating the level, delay, and equalization parameters using this model, the player outputs the audio source according to the calculated level, delay, and equalization parameters. This achieves fine-grained volume control for multi-source mixed playback, possessing the advantages of comprehensively considering source characteristics, ambient noise, and the in-vehicle sound field model to achieve fine-grained control of multi-source mixed playback, improving the clarity of high-priority information, and optimizing the overall listening experience.

Description

Technical Field

[0001] This application relates to the field of in-vehicle audio processing technology, and in particular to a volume adjustment control system and method for an in-vehicle player. Background Technology

[0002] Inside modern vehicles, the in-vehicle audio system, as the core infotainment unit, is responsible for processing and playing audio signals from a wide variety of sources. These sources are extremely diverse, including but not limited to: user-selected media content, navigation system prompts or traffic alerts, phone calls made via Bluetooth-connected mobile devices, various warning sounds generated by the vehicle itself, distance warnings or voice prompts from parking assistance systems, and system prompts and voice feedback generated when the user interacts with the in-vehicle voice assistant. During the vehicle's daily operation, these audio sources may appear individually, simultaneously, or even overlap. In-vehicle audio systems typically output processed sound signals to the interior space through multiple carefully arranged speakers.

[0003] When multiple audio sources play simultaneously, in-vehicle audio systems face the significant challenge of effectively managing these sounds to ensure that critical information is not masked or interfered with. Simply linearly superimposing all audio signals can easily lead to mutual interference and masking between different sources. Adding complexity lies in the intricate acoustic environment of the vehicle and the non-uniform sound field created by multiple speakers. When the same audio source is played through different speakers, or when different audio sources are played through a combination of different speakers, the propagation, reflection, and superposition of sound in space will produce drastically different sound effects at different locations within the vehicle.

[0004] Furthermore, the spectral characteristics of ambient noise may differ in different areas of the vehicle. For example, high-frequency wind noise near the windows may be more pronounced than in the center of the cabin. If the system adjusts the volume and spectrum based solely on the ambient noise spectrum collected from the center of the cabin, it may fail to adapt to the noise characteristics of local areas (such as near the driver's or passenger's ears), resulting in high-priority information being unclear in high-noise areas or excessively loud in low-noise areas, thus affecting comfort.

[0005] In summary, in complex scenarios involving in-vehicle multi-speaker systems, multiple audio sources with different priorities, spectral and temporal characteristics playing simultaneously, environmental noise that dynamically changes over time and has spectral characteristics, complex in-vehicle acoustic environments, and spatially uneven sound fields, how in-vehicle player systems can accurately and in real time analyze the aforementioned signal and environmental characteristics, and based on this, perform refined parameter control on the playback of different audio sources on different speakers, is a key technical problem that current in-vehicle audio systems urgently need to solve. Summary of the Invention

[0006] In view of the shortcomings of the prior art, this application provides a volume adjustment control system and method for an in-vehicle player, which is applied in the field of technology. It has the advantages of being able to comprehensively consider the characteristics of the sound source, environmental noise and the in-vehicle sound field model, realize fine control of multi-source mixed playback, improve the clarity of high-priority information and optimize the overall listening experience.

[0007] In a first aspect, a volume adjustment and control system for an in-vehicle player is provided for processing mixed playback of multiple audio sources in an in-vehicle multi-speaker system, the system comprising:

[0008] First acquisition module: Acquires multi-channel audio signals from multiple different sources;

[0009] Analysis module: Analyzes the multiple audio source signals and identifies the audio source type, priority, and spectral characteristics of each audio source signal;

[0010] The second acquisition module: collects ambient sound signals inside the vehicle, analyzes the ambient sound signals, and obtains the sound pressure level and spectral distribution of the ambient noise;

[0011] Modeling module: Creates a sound field model that describes the in-vehicle acoustic environment and the layout of multiple speakers;

[0012] Calculation module: Based on the sound source type, priority, spectral characteristics, ambient noise sound pressure level, spectral distribution, and sound field model, calculate the level, delay, and equalization parameters of each sound source signal on each speaker channel;

[0013] Playback module: Based on the calculated level, delay, and equalization parameters, it processes the multi-channel audio signals and outputs the processed audio signals to the corresponding speaker channels.

[0014] This application proposes a volume control system for an in-vehicle player. By acquiring multiple audio source signals and identifying the source type, priority, and spectral characteristics of each signal, it provides a basis for subsequent differentiated processing. It analyzes the sound pressure level and spectral distribution of ambient noise to compensate for subsequent volume adjustments, ensuring that important information can still be heard in noisy environments. By establishing a sound field model and calculating the level, delay, and equalization parameters using this model, the player outputs the audio source according to the calculated level, delay, and equalization parameters. This achieves fine-grained volume control for multi-source mixed playback, thus solving the problems mentioned in the background art, such as mutual interference between multiple audio sources, the influence of ambient noise, and the complex sound field, thereby improving the performance and user experience of the in-vehicle audio system.

[0015] Furthermore, the analysis module includes:

[0016] Preliminary analysis module: performs preliminary analysis on the multi-source audio signals to identify the source type and priority of each audio signal;

[0017] Determination module: Based on the sound source type and priority, determine the high-priority sound sources that need to be analyzed in detail;

[0018] Signal enhancement module: Based on the high-priority audio source, performs signal enhancement processing on the multi-channel audio source signals to obtain an enhanced audio source signal;

[0019] Spectrum acquisition module: Performs spectrum analysis on the enhanced audio source signal to obtain the spectral characteristics of each audio source signal.

[0020] This application proposes a volume adjustment control system for an in-vehicle player. By refining the functions of the analysis module, it introduces the identification and enhancement processing of high-priority audio sources, thereby more accurately obtaining the spectral characteristics of audio sources, especially the spectral information of high-priority audio sources, in multi-source mixing and noisy environments. This lays the foundation for subsequent accurate calculation of playback parameters and solves the problem of difficulty in accurately analyzing the spectral characteristics of various audio sources in complex acoustic scenarios.

[0021] Furthermore, the signal enhancement module includes:

[0022] The third acquisition module acquires the preliminary spectral characteristics of the high-priority sound source and the spectral distribution of the ambient noise.

[0023] Frequency enhancement determination module: Based on the source type, preliminary spectral characteristics, and spectral distribution of the high-priority audio source, determine the key frequency range of the high-priority audio source in the multi-channel audio source signal and the enhancement gain within the key frequency range;

[0024] Frequency enhancement module: processes the multi-channel audio source signals and applies the enhancement gain within the key frequency range to obtain enhanced audio source signals.

[0025] This application proposes a volume adjustment control system for a car audio player. By refining the signal enhancement module, it can more effectively improve the audibility of high-priority audio sources in complex noise environments, thus solving the problem that existing solutions fail to fully consider the impact of environmental noise in signal enhancement.

[0026] Furthermore, the second acquisition module includes:

[0027] First acquisition module: Acquires the in-vehicle ambient sound signal, including ambient noise and the sound source being played;

[0028] Fourth acquisition module: Acquires the playback audio source signal currently being played through the speaker;

[0029] Separation module: Based on the playback audio source signal, separates the ambient noise signal from the in-vehicle ambient sound signal;

[0030] The fifth acquisition module analyzes the environmental noise signal to acquire the sound pressure level and the spectral distribution.

[0031] This application proposes a volume adjustment control system for an in-vehicle player. By refining the function of the second acquisition module, it avoids interference from the playback audio source on the environmental noise analysis, provides more reliable environmental noise data for the subsequent calculation module, and enables the system to more effectively adjust the playback parameters of each audio source according to the actual environmental noise situation, thereby improving the playback effect.

[0032] Furthermore, the modeling module includes:

[0033] Test module: Measurement equipment is placed in a preset target area inside the vehicle, and test signals are played through each speaker;

[0034] Second acquisition module: Acquires acoustic environmental signals received by the measurement equipment;

[0035] Sound field construction module: Based on the acoustic environment signal and the played test signal, calculate the acoustic propagation characteristics from each loudspeaker to the target area, and construct the sound field model.

[0036] Furthermore, the sound field construction module includes:

[0037] Signal processing module: Based on the played test signal, processes the acoustic environment signal to calculate the acoustic response from each speaker to the target area;

[0038] Extraction module: Extracts feature information reflecting the amplitude, delay, and frequency response of sound propagation from the acoustic response;

[0039] Sound field construction unit: Constructs the sound field model based on the feature information.

[0040] Furthermore, the computing module includes:

[0041] The segmentation module determines high-priority and non-high-priority sound sources based on the sound source type and priority.

[0042] First calculation module: Based on the spectral characteristics, the sound pressure level of the ambient noise, the spectral distribution, and the sound field model, calculates the first level, first delay, and first equalization parameters required to achieve the target sound pressure level in the key frequency range of the target area when the high-priority sound source is played through each loudspeaker, and the second level, second delay, and second equalization parameters required to achieve the desired acoustic effect in the target area when the non-high-priority sound source is played.

[0043] The second calculation module integrates the first level, the first delay, the first equalization parameter, the second level, the second delay, and the second equalization parameter to obtain the level, the delay, and the equalization parameter of each audio source signal on each speaker channel.

[0044] Furthermore, the second computing module includes:

[0045] Strategy determination module: Obtains the priority of the high-priority sound source and the importance of the target region, and determines a trade-off strategy based on the importance;

[0046] Parameter adjustment module: Adjusts the first level, the first delay, the first equalization parameter, the second level, the second delay, and the second equalization parameter according to the trade-off strategy;

[0047] The third calculation module calculates the adjusted audio source signals' levels, delays, and equalization parameters on each speaker channel.

[0048] Furthermore, the playback module includes:

[0049] First processing module: performs level adjustment, delay processing, and frequency equalization on each audio source signal according to the level, delay, and equalization parameters;

[0050] Limiting module: acquires the maximum output capability information of the loudspeaker, and limits the signal after level adjustment, delay processing and frequency equalization according to the maximum output capability information;

[0051] Output module: Outputs the limited audio source signals to the corresponding speaker channels.

[0052] Secondly, a volume adjustment control method for an in-vehicle media player, applied to any of the systems described above, the method comprising:

[0053] S1: Acquire multi-channel audio signals from multiple different sources;

[0054] S2: Analyze the multi-channel audio signals to identify the audio source type, priority, and spectral characteristics of each audio source signal;

[0055] S3: Collect ambient sound signals inside the vehicle, analyze the ambient sound signals, and obtain the sound pressure level and spectral distribution of the ambient noise;

[0056] S4: Establish a sound field model that describes the in-vehicle acoustic environment and the layout of multiple speakers;

[0057] S5: Based on the sound source type, priority, spectral characteristics, ambient noise sound pressure level, spectral distribution, and sound field model, calculate the level, delay, and equalization parameters of each sound source signal on each speaker channel;

[0058] S6: Based on the calculated level, delay, and equalization parameters, process the multi-channel audio source signals and output the processed audio source signals to the corresponding speaker channels.

[0059] Beneficial Effects: The volume adjustment control system and method for an in-vehicle player proposed in this application acquires multiple audio source signals and identifies the source type, priority, and spectral characteristics of each signal, providing a basis for subsequent differentiated processing; analyzes the sound pressure level and spectral distribution of ambient noise to compensate for subsequent volume adjustment, ensuring that important information can still be heard in a noisy background; establishes a sound field model and calculates the level, delay, and equalization parameters using the model, and finally, the player outputs the audio source according to the calculated level, delay, and equalization parameters, achieving fine-grained volume control for multi-source mixed playback. This solves the problems mentioned in the background art, such as mutual interference between multiple audio sources, the influence of ambient noise, and the complex sound field, improving the performance and user experience of the in-vehicle audio system. It has the advantages of comprehensively considering the characteristics of the audio sources, ambient noise, and the in-vehicle sound field model to achieve fine-grained control of multi-source mixed playback, improving the clarity of high-priority information, and optimizing the overall listening experience. Attached Figure Description

[0060] Figure 1 This is a structural diagram of a volume control system for a car audio player proposed in this application.

[0061] Figure 2 This is a flowchart of a volume adjustment control method for a car audio player proposed in this application.

[0062] Figure 3 This is a schematic diagram of a volume control system for a car audio player proposed in this application.

[0063] Labeling Explanation: 101, First Acquisition Module; 102, Analysis Module; 103, Second Acquisition Module; 104, Modeling Module; 105, Calculation Module; 106, Playback Module. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0065] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0066] In a first aspect, a volume control system for an in-vehicle player is provided for handling mixed playback of multiple audio sources in an in-vehicle multi-speaker system, the system comprising:

[0067] First acquisition module 101: Acquires multi-channel audio signals from multiple different sources;

[0068] Analysis module 102: Analyzes multiple audio source signals and identifies the audio source type, priority, and spectral characteristics of each audio source signal;

[0069] The second acquisition module 103: collects ambient sound signals inside the vehicle, analyzes the ambient sound signals, and obtains the sound pressure level and spectrum distribution of ambient noise;

[0070] Modeling Module 104: Establish a sound field model describing the in-vehicle acoustic environment and the layout of multiple speakers;

[0071] Calculation module 105: Calculates the level, delay, and equalization parameters of each audio source signal on each speaker channel based on the audio source type, priority, spectral characteristics, sound pressure level of ambient noise, spectral distribution, and sound field model.

[0072] Playback module 106: Based on the calculated level, delay and equalization parameters, it processes the multi-source audio signals and outputs the processed audio signals to the corresponding speaker channels.

[0073] The first acquisition module 101 is a unit used to receive signals from different audio sources. It can be implemented using various audio input interfaces, such as analog input ports, digital input ports, and network audio interfaces. Its main purpose is to acquire the original audio signals that need to be processed and played.

[0074] The analysis module 102 is a unit used to process and identify the input audio signal. It can be implemented using signal processing algorithms, pattern recognition technology, and machine learning models, such as spectrum analysis algorithms, sound source separation algorithms, and classifiers. Its main purpose is to extract key attribute information of the sound source to provide a basis for subsequent decision-making.

[0075] The second acquisition module 103 refers to a unit used to collect in-vehicle sound and analyze the characteristics of environmental noise. It can be implemented using a microphone array, a sound pressure meter, or a real-time spectrum analyzer. For example, microphones installed in different locations in the vehicle and audio acquisition circuits connected to the processing unit are used to acquire information on the intensity and frequency distribution of the current in-vehicle environmental noise.

[0076] Modeling module 104 refers to the unit used to construct a mathematical model describing the acoustic characteristics inside the vehicle. It can be implemented using acoustic measurement technology, sound field simulation software, and room acoustic modeling algorithms. For example, a transfer function model can be established by playing a test signal and measuring the response. Its main purpose is to understand the propagation law of sound in the vehicle space.

[0077] The calculation module 105 is a unit used to calculate audio playback parameters based on various input information. It can be implemented using a digital signal processor (DSP), a high-performance microcontroller, or an audio processing algorithm library. For example, it can calculate the gain, delay, and equalization coefficients of each channel based on optimization algorithms. Its main purpose is to determine how to adjust the audio source signals of each channel to achieve the desired listening effect.

[0078] The playback module 106 refers to the unit used to apply calculated parameters to the audio signal and output it to the speaker. It can be implemented using a digital audio processor, a multi-channel audio interface, or a power amplifier, such as a chip with integrated audio processing functions or an output circuit connected to the speaker. Its main purpose is to drive the speaker to produce sound using the processed audio signal.

[0079] The core innovation of this application lies in combining multi-source audio signal analysis, in-vehicle environmental noise analysis, and in-vehicle sound field model. This allows for the calculation of targeted and refined playback parameters for each audio source on each speaker channel based on the characteristics of the audio source itself, environmental interference, and spatial acoustic environment. This achieves the goal of optimizing the mixed playback effect of multiple audio sources in complex in-vehicle environments.

[0080] As a preferred embodiment, the solution of this application is specifically implemented as follows:

[0081] The first acquisition module 101 can use various audio input interfaces integrated into the vehicle infotainment system, such as USB interface, Bluetooth receiver module, navigation voice output interface, etc., to receive audio streams from different sources such as user media, telephone, and navigation.

[0082] The analysis module 102 can employ a digital signal processor (DSP) to run a sound source classification algorithm (e.g., based on support vector machines or neural networks), priority judgment logic, and fast Fourier transform (FFT) algorithm to analyze the type, priority, and spectrum of each sound source signal in real time.

[0083] The second acquisition module 103 can use multiple microphones arranged near the driver and passenger positions inside the vehicle to collect the sound inside the vehicle, and run an adaptive noise cancellation algorithm through an audio processing unit to separate the environmental noise from the collected sound, and then perform sound pressure level and spectrum analysis.

[0084] The modeling module 104 can collect acoustic responses by placing a measurement microphone at a specific location inside the vehicle before the vehicle leaves the factory or through a user setup process, playing sweep frequency signals or pulse signals, and using these response data to construct a sound field model based on room acoustic principles, which is then stored in the system's memory.

[0085] The calculation module 105 can use another high-performance DSP or vehicle main control chip to run a multi-objective optimization algorithm based on the data provided by the analysis module, the second acquisition module and the modeling module, to calculate the channel level, delay and equalization parameters that make the high-priority sound source clearly distinguishable in the target area, while taking into account the listening experience of other sound sources.

[0086] The playback module 106 can use a multi-channel audio interface chip and multiple audio power amplifiers to receive parameters output by the computing module and the original audio source signal, perform digital audio processing (such as gain adjustment, delay, EQ filtering), and drive the speakers in the vehicle to produce sound through the power amplifiers after processing the multi-channel audio signal.

[0087] Through the above-described solution, this application addresses the problems of mutual interference between sound sources, masking of key information, and poor sound quality caused by the complex in-vehicle acoustic environment and dynamic ambient noise during mixed playback in in-vehicle multi-speaker systems. The system comprehensively analyzes the sound sources, ambient noise, and sound field characteristics, calculates and applies refined playback parameters, enabling different sound sources to be presented appropriately within the vehicle space according to their importance. This ensures that high-priority information is clearly transmitted even in noisy environments, while simultaneously optimizing the overall listening experience.

[0088] Furthermore, the analysis module includes:

[0089] Preliminary Analysis Module: Performs preliminary analysis on multiple audio source signals, identifying the audio source type and priority of each audio source signal;

[0090] Module identification: Based on the type and priority of the audio source, identify the high-priority audio sources that require focused analysis;

[0091] Signal enhancement module: Based on high-priority audio sources, it performs signal enhancement processing on multiple audio source signals to obtain enhanced audio source signals;

[0092] Spectrum acquisition module: Performs spectrum analysis on the enhanced audio source signal to obtain the spectral characteristics of each audio source signal.

[0093] This analysis module achieves accurate analysis of multi-source audio signals by breaking down the complex audio source analysis process into several logically consecutive steps.

[0094] The initial analysis module receives raw multi-channel audio signals and performs basic identification work to distinguish the signal types (e.g., voice, music, warning sounds) and their preset priorities. The preset priorities are set in advance by technicians; for example, voice and navigation are high-priority audio sources, while music is a non-high-priority audio source.

[0095] This initial identification information is passed to the determination module, which, based on a preset strategy or the current system state, clearly identifies the high-priority audio sources that need to be focused on and processed from a variety of audio sources.

[0096] The signal enhancement module receives the original multi-source audio signals and identifies high-priority audio source information. The core function of the signal enhancement module is to perform targeted enhancement processing on the original mixed signal for these high-priority audio sources. This enhancement processing does not simply increase the overall volume, but rather uses specific algorithms (such as the Expectation-Maximization (EM) algorithm: achieving joint dual-speech speech separation and dereverberation through the Extended Kalman Expectation-Maximization (KEMI) algorithm. This method performs excellently when processing multiple audio sources, effectively separating the target speech and suppressing background noise) to improve the relative loudness, intelligibility, or audibility of high-priority audio sources in the mixed signal, while potentially suppressing the influence of non-high-priority audio sources or environmental noise. After signal enhancement processing, an enhanced audio source signal is obtained, in which the characteristics of high-priority audio sources are highlighted.

[0097] The spectrum acquisition module can use wavelet analysis to perform spectrum analysis on the enhanced audio source signal. Since high-priority audio sources have already been optimized in the enhanced signal, the spectrum analysis performed at this stage can more accurately capture the true spectral characteristics of high-priority audio sources, while also providing a clearer analysis of the spectral information of other audio sources. Through this process of identification, enhancement, and analysis, the analysis module can overcome the challenges posed by multi-source mixing and noise masking, obtaining more accurate and reliable spectral characteristics of each audio source signal than directly analyzing the original mixed signal. These spectral characteristics describe the behavior and features of each audio source signal in the frequency domain, including but not limited to frequency range, spectral amplitude, and spectral shape.

[0098] This accurate spectral information is then passed to the system's computing module, which, combined with ambient noise and sound field models, calculates more precise level, delay, and equalization parameters. This enables the entire system to achieve more effective volume adjustment and mixing control, ensuring that high-priority information is clearly audible in complex in-vehicle acoustic environments.

[0099] Furthermore, the signal enhancement module includes:

[0100] The third acquisition module: acquires the preliminary spectral characteristics of high-priority sound sources and the spectral distribution of ambient noise;

[0101] Frequency enhancement determination module: Based on the source type, preliminary spectral characteristics, and spectral distribution of the high-priority audio source, determine the key frequency range of the high-priority audio source in the multi-source audio signal and the enhancement gain within the key frequency range;

[0102] Frequency enhancement module: Processes multiple audio source signals and applies enhancement gain within the key frequency range to obtain enhanced audio source signals.

[0103] The third acquisition module is used to acquire the preliminary spectral characteristics of high-priority audio sources and the spectral distribution of ambient noise. Preliminary spectral characteristics refer to the distribution of sound energy at different frequencies of the high-priority audio source in its original state before mixing with other audio sources, which helps to understand the inherent frequency characteristics of the audio source. The spectral distribution of ambient noise refers to the energy levels of in-vehicle ambient noise at different frequencies, reflecting the frequency composition of the noise. Acquiring these two types of information is fundamental for targeted signal enhancement; the former provides the target information characteristics that need to be highlighted, and the latter provides the interference information characteristics that need to be countered.

[0104] The frequency enhancement determination module is used to determine the key frequency range of the high-priority audio source in the multi-source audio signal and the enhancement gain within the key frequency range, based on the audio source type, preliminary spectral characteristics, and the spectral distribution of ambient noise. The audio source type provides high-level information about the nature of the high-priority audio source, such as whether it is speech, warning tone, or other types. The frequency range and importance of the key information usually differ for different types of audio sources.

[0105] Preliminary spectral characteristics provide detailed information on the frequency energy distribution of the sound source. The spectral distribution of ambient noise reveals which frequency regions have high noise energy and may mask high-priority sound sources. The frequency enhancement determination module comprehensively utilizes these three types of information to identify frequency regions that contain key information about the high-priority sound source and are severely affected by ambient noise, defining these regions as critical frequency ranges. Simultaneously, based on this information, it calculates the required gain within these critical frequency ranges to effectively overcome the masking effect of ambient noise and achieve the desired audibility for the high-priority sound source within that range. This multi-dimensional information-based determination process allows the signal enhancement strategy to intelligently adapt to different sound sources and noise environments.

[0106] The process of calculating the key frequency range and the enhancement gain within that range includes:

[0107] ① For each frequency point, calculate the ratio (signal-to-noise ratio) of the spectral amplitude of the high-priority sound source to the spectral amplitude of the ambient noise: ,in, This represents the spectral amplitude of a high-priority audio signal at frequency f. This represents the spectral amplitude of environmental noise at frequency f.

[0108] ② Select a frequency range with a low signal-to-noise ratio (the signal-to-noise ratio can be set). The range of frequencies is considered the critical frequency range. These frequency ranges are typically areas where the critical information of high-priority audio sources is masked by noise.

[0109] ③ Set the target signal-to-noise ratio (SNR). For each key frequency point, calculate the required enhancement gain to make the SNR at that frequency point reach the target SNR: Gain(f) = Target SNR - SNR(f), where Gain(f) is the calculated gain. If the calculated gain is negative, it means that the SNR at that frequency point is already higher than the target SNR, and no enhancement is needed.

[0110] Furthermore, the second acquisition module includes:

[0111] First acquisition module: Acquires in-vehicle ambient sound signals including environmental noise and the sound source being played;

[0112] Fourth acquisition module: Acquires the audio source signal currently being played through the speaker;

[0113] Separation module: Based on the audio source signal being played, separates the ambient noise signal from the ambient sound signal inside the vehicle;

[0114] The fifth acquisition module analyzes environmental noise signals to obtain sound pressure levels and spectral distribution.

[0115] This solution provides a more accurate method for acquiring in-vehicle environmental noise information by refining the functions of the second acquisition module.

[0116] Specifically, the first acquisition module is responsible for acquiring the actual acoustic environment signal inside the vehicle. This signal is a mixed signal of ambient noise and the sound source being played, superimposed in the vehicle space. It can be acquired using a microphone array or a single microphone.

[0117] The fourth acquisition module acquires the original playback audio source signal that the system is currently playing through the speaker, and this signal is known.

[0118] The separation module uses the known playback sound source signal obtained by the fourth acquisition module to eliminate the interference of the playback sound source on the acquired signal through adaptive filtering, thereby separating the relatively pure environmental noise signal from the mixed in-vehicle environmental sound signal.

[0119] The fifth acquisition module uses a sound pressure level measurement method to analyze the separated environmental noise signal, thereby enabling more accurate acquisition of the sound pressure level and spectral distribution of the in-vehicle environmental noise.

[0120] In this way, the solution avoids interference from the playback audio sources on environmental noise analysis, providing more reliable environmental noise data for subsequent calculation modules. This allows the system to more effectively adjust the playback parameters of each audio source based on the actual environmental noise conditions, improving playback quality. This more accurate environmental noise information, combined with the characteristics, priorities, and sound field models of the multi-source audio signals acquired by the system, enables the calculation module to perform more precise parameter calculations. Consequently, when the playback module outputs sound, it can better balance different audio sources, adapt to the in-vehicle acoustic environment and noise, and achieve a superior listening experience.

[0121] Furthermore, the modeling module includes:

[0122] Test module: Measurement equipment is placed in a preset target area inside the vehicle, and test signals are played through each speaker;

[0123] Second acquisition module: Acquires acoustic environmental signals received by the measurement equipment;

[0124] Sound field construction module: Based on the acoustic environment signal and the played test signal, calculate the acoustic propagation characteristics from each speaker to the target area and construct a sound field model.

[0125] This solution provides a specific method for establishing an in-vehicle sound field model by defining the composition and function of the modeling module. This solves the problem of only stating the need to establish a sound field model without providing a specific method for doing so, thus improving the accuracy of the sound field model.

[0126] The working principle of this scheme is as follows: The test module first places measuring equipment in a preset target area inside the vehicle (e.g., the location of a passenger's ear), and controls the system to play known test signals through each speaker. This step provides controlled input signals and measurement points for measuring the sound field characteristics, and is a necessary prerequisite for obtaining the in-vehicle acoustic response.

[0127] Subsequently, the second acquisition module is responsible for acquiring the acoustic environment signal received by the measuring equipment when the test signal is played. This signal contains the actual effect of the test signal after propagating through the complex acoustic environment inside the vehicle, and is the raw data for analyzing the acoustic propagation characteristics.

[0128] Finally, the sound field construction module calculates the acoustic propagation characteristics of sound from each speaker to the target area, such as amplitude, delay, and frequency response, based on the played test signal (known input) and the collected acoustic environment signal (actual output).

[0129] By comparing input and output signals, the changes in sound along a specific path can be accurately quantified. Based on these calculated acoustic propagation characteristics, the sound field construction module can build a sound field model describing the in-vehicle acoustic environment and the layout of multiple speakers. This model accurately reflects the propagation patterns and spatial distribution of sound within the vehicle.

[0130] This modeling method, combined with the system's functions of acquiring sound source signals, analyzing sound source characteristics, and collecting and analyzing environmental noise, provides a reliable basis for subsequent calculation modules to accurately calculate the level, delay, and equalization parameters of each sound source on each speaker channel based on sound source characteristics, environmental noise, and the sound field model. This sound field model construction method based on actual measurements can more accurately reflect the complexity and non-uniformity of the in-vehicle acoustic environment, enabling subsequent parameter calculations to better adapt to these characteristics, thereby achieving more optimized volume adjustment and sound effects.

[0131] Furthermore, the sound field construction module includes:

[0132] Signal processing module: Based on the played test signal, it processes the acoustic environment signal to calculate the acoustic response from each speaker to the target area;

[0133] Extraction module: Extracts feature information reflecting the amplitude, delay, and frequency response of sound propagation from the acoustic response;

[0134] Sound field construction unit: Constructs a sound field model based on feature information.

[0135] Based on the above components, the working principle of this solution is as follows: This solution provides a specific process for obtaining the acoustic propagation characteristics required to construct the sound field model from test signals and acquired acoustic environment signals by refining the internal structure of the sound field construction module, thereby solving the problem that there is room for improvement in the accuracy or efficiency of constructing the sound field model.

[0136] Specifically, since the acquired acoustic environment signal includes the result of the test signal played by the speaker propagating through the in-vehicle acoustic environment, and may also include ambient noise and reverberation, the signal processing module processes the acquired acoustic environment signal based on the known test signal to obtain the transfer function or impulse response from the speaker to the target area. This can be achieved using deconvolution or cross-correlation algorithms. Specifically, the formula for calculating the acoustic response is: ,in, It is a test signal. It is an ambient acoustic signal. It is an acoustic response.

[0137] The acoustic response contains rich information about acoustic propagation. The extraction module analyzes this information to extract key features reflecting the laws of sound propagation, including amplitude, delay, and frequency response. Specifically, the extraction is implemented as follows:

[0138] The amplitude is obtained by calculating the amplitude spectrum of the acoustic response: , Indicates Fourier transform, It is the spectrum of the acoustic response.

[0139] Delay: Calculated using a cross-correlation algorithm. .

[0140] By analyzing the spectrum of the acoustic response Characteristics, thus obtaining the frequency response.

[0141] These features are direct quantifications describing the attenuation, propagation time, and frequency response changes of sound along a specific propagation path. Finally, the sound field construction unit uses this quantification information to build a mathematical model describing the in-vehicle acoustic environment and the layout of multiple speakers. Specifically, the formula for constructing the sound field model is: ,in It is the acoustic transfer function from the i-th loudspeaker to the j-th target region. It is an amplitude response. It is a phase response.

[0142] By employing this step-by-step processing and feature extraction method, this scheme can extract the characteristics reflecting the laws of sound propagation required for constructing a sound field model from the acquired signals containing complex information. This improves the accuracy of sound field model construction, simplifies the model structure, and increases the efficiency of the construction process.

[0143] In this way, the constructed sound field model can reflect the propagation pattern of sound in the vehicle interior.

[0144] Furthermore, the computing module includes:

[0145] Module division: Determine high-priority and non-high-priority audio sources based on audio source type and priority;

[0146] First calculation module: Based on the spectral characteristics, ambient noise sound pressure level, spectral distribution, and sound field model, calculates the first level, first delay, and first equalization parameters required to achieve the target sound pressure level in the key frequency range of the target area when high-priority sound sources are played through each loudspeaker, and the second level, second delay, and second equalization parameters required to achieve the desired acoustic effect in the target area when non-high-priority sound sources are played.

[0147] The second calculation module integrates the first level, first delay, first equalization parameter, second level, second delay, and second equalization parameter to obtain the level, delay, and equalization parameters of each audio source signal on each speaker channel.

[0148] This solution refines the functions of the calculation module and adopts differentiated calculation strategies for audio sources of different priorities. This effectively improves the clarity and intelligibility of high-priority information in complex acoustic environments with mixed playback of multiple audio sources, while optimizing the playback effect of non-high-priority audio sources and solving the problems caused by unified calculation.

[0149] Specifically, the segmentation module clearly distinguishes multiple audio source signals into high-priority and non-high-priority audio sources based on the audio source type and priority. This segmentation forms the basis for subsequent differentiated processing, enabling the system to identify and prioritize key information such as navigation voices and warning sounds, preventing them from being masked during mixed playback.

[0150] The first calculation module targets high-priority audio sources. Based on their spectral characteristics, the sound pressure level and spectral distribution of ambient noise, and a pre-established sound field model, it calculates the required level, delay, and equalization parameters for playback through each speaker. The goal of this calculation is to ensure that the high-priority audio source reaches a specific target sound pressure level within the key frequency range of the target area. This means the system considers the masking effect of ambient noise and the impact of the sound field on sound propagation, dynamically adjusting the playback parameters of the high-priority audio source. For example, it may increase gain in noisy frequency ranges or adjust delay and equalization to optimize the superposition effect of sound in the target area, thereby ensuring that key information remains clearly understandable even in complex noise and sound field environments.

[0151] Meanwhile, the first calculation module also calculates the level, delay, and equalization parameters required to achieve the desired acoustic effect in the target area during playback for non-high-priority audio sources. By calculating separately, it avoids the mutual interference and poor effect that may be caused by simple superposition or uniform processing, allowing the system to optimize non-critical audio sources such as background music while ensuring the clarity of high-priority audio sources, thereby improving the overall listening experience.

[0152] The second calculation module integrates the first parameter set (first level, first delay, first equalization parameter) calculated for high-priority audio sources with the second parameter set (second level, second delay, second equalization parameter) calculated for non-high-priority audio sources. The integration process combines the optimized playback parameters of the two types of audio sources to obtain a unified parameter set applied to each audio source signal on each speaker channel. This provides a refined control basis for the subsequent playback module, enabling the system to collaboratively process and play multiple audio source signals based on the priority and characteristics of different audio sources, as well as real-time environmental noise and sound field information. Ultimately, this achieves a mixed listening experience where high-priority information is highlighted while non-high-priority information is played well. By combining audio source segmentation, parameter calculation based on environmental noise, spectral characteristics, and sound field models, and parameter integration, this solution can dynamically and precisely adjust playback parameters according to the characteristics of different audio sources and their acoustic environment. This effectively improves the clarity of key information in complex scenarios involving mixed playback of multiple audio sources, while optimizing the playback experience of non-key information, significantly improving the overall listening experience.

[0153] Furthermore, the second computing module includes:

[0154] Strategy determination module: Obtain the priority of high-priority audio sources and the importance of target regions, and determine the trade-off strategy based on importance;

[0155] Parameter adjustment module: Adjusts the first level, first delay, first equalization parameter, second level, second delay, and second equalization parameter according to the trade-off strategy;

[0156] The third calculation module calculates the adjusted audio source signals' levels, delays, and equalization parameters on each speaker channel.

[0157] This solution achieves its functionality through the collaborative work of the aforementioned modules. The strategy determination module is the functional unit responsible for determining how to balance the audio source playback effect based on the input information; it can be implemented using software algorithms running on the processor.

[0158] The priority of a high-priority audio source refers to the attribute assigned to it to indicate its relative importance. This priority can be expressed as a numerical value or a preset level.

[0159] The importance of the target area refers to the attribute assigned to a specific listening area in the vehicle to indicate the degree of significance of that area, which can be expressed by numerical values ​​or preset levels.

[0160] The trade-off strategy refers to a set of rules that guide how to adjust audio parameters according to priority and importance, which can be implemented using lookup tables, algorithm sets, or model outputs.

[0161] The parameter adjustment module is a functional unit that modifies the initial audio parameters according to a trade-off strategy. It can be implemented using software algorithms that apply scaling factors, offsets, or transformations.

[0162] The third calculation module is a functional unit that calculates the final audio parameters of each speaker channel based on the adjusted parameters. It can be implemented using software algorithms that apply matrix operations or signal processing algorithms.

[0163] Specifically, the strategy determination module first obtains the priority information of the currently playing high-priority audio source and the importance information of the target area to which the sound needs to be delivered. Based on this information, the module determines a trade-off strategy that defines how to balance the delivery of high-priority audio sources with the listening experience of non-high-priority audio sources in the current scenario. For example, when navigation voice (high priority) is played in the driver's area (important area), the strategy may prioritize ensuring the clarity of the navigation voice. The parameter adjustment module receives the high-priority audio source parameters and non-high-priority audio source parameters calculated by the first calculation module. This module adjusts these parameters according to the trade-off strategy output by the strategy determination module. This adjustment is a strategy-based optimization process; for example, according to the strategy, the level parameter of the high-priority audio source on the corresponding speaker channel in the target area is increased, while for background music, the level parameter on the corresponding speaker channel in the driver's area is decreased according to the strategy.

[0164] The third calculation module receives the adjusted parameters output by the parameter adjustment module and, based on these adjusted parameters, calculates the final applied level, delay, and equalization parameters for each audio source signal on each speaker channel. These final parameters comprehensively consider audio source priority, target area importance, and conflicts between audio sources, ensuring information is presented in important areas while optimizing the listening experience. By introducing strategy determination and parameter adjustment stages, this solution can weigh and adjust the playback parameters of the audio sources according to the situation, overcoming the limitations of simple integration solutions.

[0165] Furthermore, the playback module includes:

[0166] The first processing module performs level adjustment, delay processing, and frequency equalization on each audio source signal based on the level, delay, and equalization parameters.

[0167] Limiting module: Obtains the maximum output capability information of the loudspeaker, and limits the signal after level adjustment, delay processing and frequency equalization based on the maximum output capability information;

[0168] Output module: Outputs the limited audio source signals to the corresponding speaker channels.

[0169] Among these, level adjustment refers to the gain or attenuation of the audio signal amplitude. Delay processing refers to introducing a certain time delay into the audio signal. Frequency equalization refers to adjusting the relative intensity of different frequency components in the audio signal. Maximum output capability information refers to data describing the maximum signal amplitude or power that a speaker can handle without significant distortion or damage. Limiting refers to the process of limiting the instantaneous amplitude of a signal to below a preset maximum value.

[0170] Through the above structure and processing flow, the technical solution of this application can effectively solve the problem that the amplitude of the processed signal exceeds the range that the speaker can withstand.

[0171] Specifically, the first processing module receives level, delay, and equalization parameters from the calculation module. These parameters are derived from a comprehensive analysis and calculation of the audio source signal, ambient noise, and in-vehicle sound field model, aiming to optimize the playback effect of each audio source signal in the vehicle space. For example, it can improve the clarity of high-priority audio sources, suppress the influence of ambient noise, or create a desired sound field distribution in specific areas. Based on these parameters, the first processing module performs precise level adjustment, delay processing, and frequency equalization on the original audio source signal to generate a pre-processed signal.

[0172] The limiting module intervenes before sending these pre-processed signals to the speakers. The limiting module pre-acquires the physical characteristics of the connected speakers, specifically their maximum output capability. This information reflects the maximum signal amplitude the speakers can safely and reliably reproduce. Based on this maximum output capability information, the limiting module monitors and processes the pre-processed signals in real time. If the instantaneous amplitude of the signal exceeds the maximum value the speaker can withstand, the limiting module immediately limits the signal, reducing its amplitude to a safe range. This limiting process, based on the speaker's own physical characteristics, ensures that regardless of the parameters output by the preceding calculation module, the signal ultimately sent to the speaker will not exceed its physical limits.

[0173] Finally, the output module sends the limited signal to the corresponding speaker channel for playback. This processing flow combines complex acoustic optimization calculations with the physical limitations of the actual playback hardware, forming a complete signal processing chain. The preceding modules calculate ideal playback parameters based on complex environmental and audio source conditions, while the playback module applies these parameters and uses limiting processing to ensure that the ideal parameters are physically achievable and safe.

[0174] This combination enables the system to achieve both precise sound field control and sound quality optimization, while ensuring playback stability and device safety, avoiding distortion and speaker damage caused by signal overload.

[0175] Secondly, a volume adjustment control method for an in-vehicle media player, applied to any of the above-mentioned systems, includes:

[0176] S1: Acquire multi-channel audio signals from multiple different sources;

[0177] S2: Analyze multiple audio source signals and identify the audio source type, priority, and spectral characteristics of each audio source signal;

[0178] S3: Collect ambient sound signals inside the vehicle, analyze the ambient sound signals, and obtain the sound pressure level and spectral distribution of ambient noise;

[0179] S4: Establish a sound field model that describes the in-vehicle acoustic environment and the layout of multiple speakers;

[0180] S5: Calculate the level, delay, and equalization parameters of each audio source signal on each speaker channel based on the audio source type, priority, spectral characteristics, ambient noise sound pressure level, spectral distribution, and sound field model.

[0181] S6: Based on the calculated level, delay, and equalization parameters, process the multi-source audio signals and output the processed audio signals to the corresponding speaker channels.

[0182] This method provides a systematic process for achieving fine-grained volume control of multiple audio sources in complex in-vehicle environments. By organizing the functional modules of the system into a series of orderly steps, this method ensures that the system can complete tasks efficiently and accurately, addressing the challenges posed by mixed audio source playback, complex acoustic environments, and dynamic environmental noise.

[0183] Specifically, step S1 acquires multi-channel audio signals from multiple different sources, providing raw input data for all subsequent processing.

[0184] Step S2 analyzes these audio source signals to identify their type, priority, and spectral characteristics, which provides a basis for subsequent priority control and spectral processing.

[0185] Step S3 collects ambient sound signals inside the vehicle and analyzes the sound pressure level and spectral distribution of ambient noise. This enables the system to understand the noise characteristics of the current environment and provides real-time data for dynamic adjustment based on ambient noise.

[0186] Based on this, step S4 establishes a sound field model describing the in-vehicle acoustic environment and the layout of multiple speakers, which provides spatial dimension information for spatial audio processing, delay alignment and equalization compensation.

[0187] Based on the previously obtained audio source attributes, environmental noise information, and sound field model, step S5 comprehensively calculates the level, delay, and equalization parameters of each audio source signal on each speaker channel. This calculation process integrates all key information to derive the precise control parameters required for each audio source and each speaker channel, aiming to optimize the auditory effect of different audio sources at different locations.

[0188] Finally, step S6 processes the multi-source audio signals based on the calculated parameters and outputs the processed signals to the corresponding speaker channels, thereby converting the analysis and calculation results into actual audible sound, achieving precise control of each audio source on different speakers, and ultimately forming the desired sound field effect in the vehicle interior.

[0189] Through the above method, this application enables precise control of multi-source audio playback in vehicles. This method comprehensively considers the properties of the audio sources themselves, dynamically changing environmental noise, and the complex in-vehicle acoustic environment, and can calculate precise control parameters for different audio sources on different speakers. This allows the system to adaptively adjust the playback effect of each audio source according to the actual situation, ensuring that high-priority information remains clear and understandable even in noisy environments, while optimizing the listening experience of non-high-priority audio sources. It effectively solves the problems of mutual interference and masking during multi-source audio playback, improving the overall performance and user experience of the in-vehicle audio system.

[0190] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0191] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A volume adjustment and control system for a car audio player, used to handle mixed playback of multiple audio sources in a car multi-speaker system, characterized in that, The volume control system of the car audio player includes: First acquisition module: Acquires multi-channel audio signals from multiple different sources; Analysis module: Analyzes the multiple audio source signals and identifies the audio source type, priority, and spectral characteristics of each audio source signal; The second acquisition module: collects ambient sound signals inside the vehicle, analyzes the ambient sound signals, and obtains the sound pressure level and spectral distribution of the ambient noise; Modeling module: Creates a sound field model that describes the in-vehicle acoustic environment and the layout of multiple speakers; The modeling module includes: The test module places measuring devices in a preset target area inside the vehicle and plays test signals through various speakers. The second acquisition module acquires acoustic environmental signals received by the measuring equipment; The sound field construction module calculates the acoustic propagation characteristics from each loudspeaker to the target area based on the acoustic environment signal and the played test signal, and constructs the sound field model. The sound field construction module includes: The signal processing module processes the acoustic environment signal based on the played test signal to calculate the acoustic response from each speaker to the target area. The extraction module extracts feature information reflecting the amplitude, delay, and frequency response of sound propagation from the acoustic response; The sound field construction unit constructs the sound field model based on the feature information. The calculation module calculates the level, delay, and equalization parameters of each audio source signal on each speaker channel based on the audio source type, priority, spectral characteristics, sound pressure level and spectral distribution of the ambient noise, and the sound field model. The playback module processes the multi-channel audio signals based on the calculated level, delay, and equalization parameters, and outputs the processed audio signals to the corresponding speaker channels.

2. The volume adjustment control system for a car audio player according to claim 1, characterized in that, The analysis module includes: The preliminary analysis module performs a preliminary analysis of the multi-channel audio signals, identifying the audio source type and priority of each audio source signal; The module determines the high-priority audio sources that need to be analyzed in detail, based on the audio source type and the priority. The signal enhancement module performs signal enhancement processing on the multi-channel audio source signals based on the high-priority audio source to obtain an enhanced audio source signal; The spectrum acquisition module performs spectrum analysis on the enhanced audio source signal to obtain the spectral characteristics of each audio source signal.

3. The volume adjustment control system for a car audio player according to claim 2, characterized in that, The signal enhancement module includes: The third acquisition module acquires the preliminary spectral characteristics of the high-priority sound source and the spectral distribution of the ambient noise. The frequency enhancement determination module determines the key frequency range of the high-priority audio source in the multi-channel audio source signal and the enhancement gain within the key frequency range based on the audio source type, preliminary spectral characteristics, and spectral distribution of the environmental noise of the high-priority audio source. The frequency enhancement module processes the multi-channel audio source signals and applies the enhancement gain within the key frequency range to obtain enhanced audio source signals.

4. The volume adjustment control system for a car audio player according to claim 1, characterized in that, The second acquisition module includes: The first acquisition module acquires the in-vehicle ambient sound signal, which includes environmental noise and the sound source being played. The fourth acquisition module acquires the audio source signal currently being played through the speaker; The separation module separates the ambient noise signal from the in-vehicle ambient sound signal based on the playback audio source signal; The fifth acquisition module analyzes the environmental noise signal to acquire the sound pressure level and the spectral distribution.

5. The volume adjustment control system for a car audio player according to claim 1, characterized in that, The computing module includes: The segmentation module determines high-priority and non-high-priority sound sources based on the sound source type and the priority. The first calculation module calculates, based on the spectral characteristics, the sound pressure level of the ambient noise, the spectral distribution, and the sound field model, the first level, the first delay, and the first equalization parameters required to achieve the target sound pressure level in the key frequency range of the target area when the high-priority sound source is played through each loudspeaker, and the second level, the second delay, and the second equalization parameters required to achieve the desired acoustic effect in the target area when the non-high-priority sound source is played. The second calculation module integrates the first level, the first delay, the first equalization parameter, the second level, the second delay, and the second equalization parameter to obtain the level, the delay, and the equalization parameter of each audio source signal on each speaker channel.

6. The volume adjustment control system for a car audio player according to claim 5, characterized in that, The second calculation module includes: The strategy determination module obtains the priority of the high-priority sound source and the importance of the target region, and determines a trade-off strategy based on the importance. The parameter adjustment module adjusts the first level, the first delay, the first equalization parameter, the second level, the second delay, and the second equalization parameter according to the trade-off strategy. The third calculation module calculates the adjusted audio source signals' levels, delays, and equalization parameters on each speaker channel.

7. The volume adjustment control system for a car audio player according to claim 1, characterized in that, The playback module includes: The first processing module performs level adjustment, delay processing, and frequency equalization on each audio source signal according to the level, delay, and equalization parameters. The limiting module acquires the maximum output capability information of the loudspeaker and limits the signal after level adjustment, delay processing and frequency equalization based on the maximum output capability information. The output module outputs the limited audio source signals to the corresponding speaker channels.

8. A method for volume adjustment control of a car audio player, characterized in that, The method, applied to the volume adjustment control system of a car audio player according to any one of claims 1-7, comprises: S1: Acquire multi-channel audio signals from multiple different sources; S2: Analyze the multi-channel audio signals to identify the audio source type, priority, and spectral characteristics of each audio source signal; S3: Collect ambient sound signals inside the vehicle, analyze the ambient sound signals, and obtain the sound pressure level and spectral distribution of the ambient noise; S4: Establish a sound field model that describes the in-vehicle acoustic environment and the layout of multiple speakers; S5: Based on the sound source type, priority, spectral characteristics, ambient noise sound pressure level, spectral distribution, and sound field model, calculate the level, delay, and equalization parameters of each sound source signal on each speaker channel; S6: Based on the calculated level, delay, and equalization parameters, process the multi-channel audio source signals and output the processed audio source signals to the corresponding speaker channels.

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