A mixing method and device for vehicle audio system

Abstract

The present invention discloses a mixing method and device for vehicle audio signals, the mixing method comprising the following steps: A. generating a reference signal according to the vehicle engine speed; B. generating a synthetic signal according to the reference signal, a multimedia signal after filtering and a weight coefficient of noise reduction control; C. generating an error signal according to the synthetic signal and the processed multimedia signal; D. estimating and updating the weight coefficient of noise reduction control according to the error signal; E. generating a mixed signal according to the synthetic signal and the processed multimedia signal. The noise reduction control of the present invention does not perform noise reduction processing on the multimedia signal, thereby ensuring the complete and accurate restoration and playback of the multimedia signal.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle-mounted active noise reduction and relates to a mixing method and device for a vehicle-mounted audio system. Background Art

[0002] With the technological progress of the automobile manufacturing industry and the continuous improvement of people's living standards, the quality level of background noise in the car cabin has begun to receive widespread attention from the NVH (Noise, Vibration, Harshness) R&D departments of many car manufacturers and consumers. The NVH departments of car manufacturers conduct comprehensive and strict index assessments on the background noise in the car to ensure that the acoustic environment in the cabin meets the comfort requirements. Since the vibration noise of the car engine will be transmitted to the cabin through the body structure, if the body structure design is unreasonable and the noise transmission path is not blocked, it will cause the cabin to produce residual background noise components of the same order as the engine. In the scenario of making voice calls or listening to music in the cabin, too much engine order noise will also cause the clarity of voice calls to decrease and the quality of music playback to deteriorate; at the same time, too much residual engine order noise will cause irritability and fatigue of the driver and passengers, and in severe cases, it will cause dizziness and headaches.

[0003] The NVH department of the car factory will consider modifying the chassis structure, adding damping materials, and adding shock-absorbing spring devices for passive noise control of engine order noise. However, this passive noise control method has a good noise reduction effect on the mid- and high-frequency noise in the cabin, but the control effect on low-frequency noise is poor. The speed of a four-cylinder fuel car generally varies in the range of 600rpm to 6000rpm, and the frequency of the second-order noise generally varies in the range of 20Hz to 200Hz. This low-frequency order noise of the engine is difficult to eliminate through passive noise control solutions. Therefore, scholars and R&D personnel at home and abroad have begun to turn to the application research of active noise control solutions in the field of automobile engine order noise control, and have achieved great success. The on-board active noise reduction system uses the existing speakers and host / amplifier systems in the car to achieve a very obvious noise reduction control effect on the engine order noise without increasing the development cost.

[0004] Since the control signal generated by active noise reduction needs to be played through the car's own speaker unit, and the speaker unit itself needs to play the multimedia signal of the car computer or amplifier, the noise reduction control signal and the multimedia signal need to be mixed when they are played back through the same speaker system. The traditional mixing processing scheme is to directly add and process the noise reduction control signal and the multimedia signal. The problem with this processing method is that when the noise reduction control signal and the multimedia signal both have the same frequency order noise associated with the engine speed, the noise reduction control algorithm will also perform noise reduction control on the signal components in the multimedia signal that are at the same frequency as the engine order noise signal. In order to ensure that the multimedia signal is not affected by the noise reduction control, our noise reduction control cannot perform noise reduction processing on the multimedia signal, thereby achieving a complete and accurate restoration of the multimedia signal.

[0005] Chinese patents CN108366320A and CN107131054A both propose mixing methods, but both of them are to add the noise reduction control signal and the multimedia signal and directly mix them. When this processing method encounters a multimedia signal containing a signal component with the same frequency as the engine order, it will be subjected to the noise reduction processing of the noise reduction control algorithm, causing the same frequency component contained in the multimedia signal to be lost due to attenuation. This is an undesirable result of the noise reduction control. The noise reduction control must ensure that the multimedia signal cannot be subjected to noise reduction processing.

[0006] In summary, the existing mixing method of vehicle-mounted noise reduction control is to directly mix the noise reduction signal with the multimedia signal. When a signal with the same frequency component as the noise reduction control signal, that is, a signal with the same frequency as the engine order, appears in the multimedia signal, the noise reduction control will perform noise reduction on the same-frequency signal in the multimedia signal, causing the same-frequency signal in the multimedia signal to attenuate, changing the spectrum characteristics of the multimedia signal, and the noise reduction control has an impact on the multimedia signal. This is a defect in the mixing scheme of the current vehicle-mounted noise reduction system. The existing mixing method of vehicle-mounted noise reduction control needs to consider the factors affecting the channel frequency response during the mixing process. The mixing process will cause the frequency response of the low-frequency band to change, which will affect the vehicle-mounted multimedia signal. Summary of the invention

[0007] In view of the defects of the existing method of directly adding and mixing noise reduction control signals and multimedia signals in the vehicle audio system, the present invention proposes a mixing method and device for vehicle audio signals. The noise reduction control will not perform noise reduction processing on the multimedia signal, thereby ensuring the complete and accurate restoration and playback of the multimedia signal.

[0008] A first aspect of the present invention provides a mixing method for a vehicle audio system, the mixing method comprising:

[0009] A. Generate a reference signal based on the vehicle engine speed;

[0010] B. generating a synthetic signal according to the reference signal, the multimedia signal after filtering and the weight coefficient of noise reduction control;

[0011] C. generating an error signal according to the synthesized signal and the processed multimedia signal;

[0012] D. estimating and updating the weight coefficient of noise reduction control according to the error signal;

[0013] E. Generate a mixed signal according to the synthesized signal and the processed multimedia signal.

[0014] Preferably, in step B, the multimedia signal is subjected to low-pass filtering before generating the synthesized signal.

[0015] Preferably, in step C, the processed multimedia signal is a multimedia signal that has been processed by low-pass filtering and transfer function filtering in sequence, and the transfer function is a transfer function from a secondary sound source to a noise reduction position.

[0016] Preferably, in step D, the reference signal is first subjected to transfer function filtering processing, and then the weight coefficients of the noise reduction control are estimated and updated according to the error signal and the processed reference signal.

[0017] Preferably, in step E, the multimedia signal is first subjected to high-pass filtering, and then the mixed signal is generated. The present invention proposes to perform equalization processing on the mixed signal, and the frequency response changes that occur during the mixing of the noise reduction control signal and the multimedia signal are ensured to be flat after mixing through equalization processing, thereby ensuring complete and accurate restoration of the multimedia signal.

[0018] Preferably, the mixed signal is sent to a power amplifier after being equalized to drive a loudspeaker to produce sound.

[0019] Preferably, in step B, the synthetic signal is generated according to formula (1-1) or formula (1-2):

[0020] y a =w0·x0+w1·x1+l·h LPF (1-1)

[0021] y a,k =w 0,k ·x0+w 1,k ·x1+l k ·h LPF (1-2)

[0022] Among them, y ais a single-channel synthetic signal, x0 and x1 are two reference signals, and their corresponding weights are w0 and w1, l is a multimedia signal, and h LPF is a low-pass filter; a,k is the composite signal of the kth channel among K channels, and the weights corresponding to the two reference signals x0 and x1 are w 0,k and w 1,k , l k is the multimedia signal corresponding to the kth channel;

[0023] And / or, in step C, the error signal is generated according to formula (2-1) or formula (2-2):

[0024] e=dy a ·h+l·h LPF ·h (2-1)

[0025] e k =d k -y a,k ·h k +l k ·h LPF ·h k (2-2)

[0026] Where, e is the error signal of a single channel, d is the order noise of the vehicle engine, and h is the transfer function from the secondary sound source to the noise reduction position; e k is the error signal corresponding to the kth channel, h k is the transfer function from the secondary sound source of the kth channel to the noise reduction position;

[0027] And / or, in step E, the mixed signal is generated according to formula (3-1) or formula (3-2):

[0028] y m =y a +l·h HPF (3-1)

[0029] y m,k =y a,k +l k ·h HPF (3-2)

[0030] Among them, y m is the mixed signal of a single channel, h HPF is a high-pass filter; y m,k is the mixed signal of the kth channel among the K channels.

[0031] Another aspect of the present invention provides a mixing device for a vehicle audio system, comprising:

[0032] a reference signal generating module for generating a reference signal associated with a vehicle engine speed;

[0033] A weight estimation module, which is used to estimate and update the weight coefficient of noise reduction control according to the error signal and the processed reference signal;

[0034] A multimedia signal generating module, which is used to generate multimedia signals;

[0035] a synthetic signal generating module, which is used to generate a synthetic signal according to the reference signal, the weight coefficient and the multimedia signal after filtering; and

[0036] A mixed signal generating module, which is used to generate a mixed signal according to the synthesized signal and the processed multimedia signal;

[0037] The sound mixing device also includes:

[0038] The error signal generating module is used to generate an error signal according to the synthesized signal and the processed multimedia signal, and send the error signal to the weight estimation module to update the weight coefficient.

[0039] Preferably, the sound mixing device further comprises:

[0040] The first channel transfer function processing module is used to receive the reference signal output by the reference signal generating module, perform channel transfer function filtering on the reference signal, and then send the result to the weight estimation module.

[0041] Preferably, the sound mixing device further comprises:

[0042] The low-pass filter processing module is used to receive the multimedia signal output by the multimedia signal generating module, perform low-pass filter processing on the multimedia signal, and then send it to the synthetic signal generating module.

[0043] Preferably, the sound mixing device further comprises:

[0044] The second channel transfer function processing module is used to receive the multimedia signal after low-pass filtering, perform channel transfer function filtering on the multimedia signal, and then send it to the error signal generating module.

[0045] Preferably, the sound mixing device further comprises:

[0046] The high-pass filter processing module is used to receive the multimedia signal output by the multimedia signal generating module, perform high-pass filter processing on the multimedia signal, and then send it to the mixing signal generating module.

[0047] Preferably, the sound mixing device further comprises:

[0048] The equalization and filtering processing module is used to receive the mixed signal output by the mixed signal generation module, and perform equalization and filtering on it before sending it to the power amplifier. By equalizing the mixed signal, the frequency response changes that occur during the mixing process of the noise reduction control signal and the multimedia signal are guaranteed to be flat after mixing through equalization, and the complete and accurate restoration of the multimedia signal is guaranteed.

[0049] Preferably, the synthetic signal generating module generates the synthetic signal according to formula (1-1) or formula (1-2):

[0050] y a =w0·x0+w1·x1+l·h LPF (1-1)

[0051] y a,k =w 0,k ·x0+w 1,k ·x1+l k ·h LPF (1-2)

[0052] Among them, y a is a single-channel synthetic signal, x0 and x1 are two reference signals output by the reference signal generation module, w0 and w1 are weight coefficients output by the weight estimation module, l is a multimedia signal output by the multimedia signal generation module, h LPF is a low-pass filter; a,k is the composite signal of the kth channel among K channels, w 0,k and w 1,k are the weight coefficients output by the weight estimation module, l k A multimedia signal corresponding to the kth channel output by the multimedia signal generating module;

[0053] And / or, the error signal generating module generates the error signal according to formula (2-1) or formula (2-2):

[0054] e=dy a ·h+l·h LPF ·h (2-1)

[0055] e k =d k -y a,k ·h k +l k ·h LPF ·h k (2-2)

[0056] Wherein, e is the error signal of a single channel, d is the order noise of the vehicle engine received by the error signal generating module, and h is the transfer function from the secondary sound source to the noise reduction position; e k is the error signal corresponding to the kth channel, h k is the transfer function from the secondary sound source of the kth channel to the noise reduction position;

[0057] And / or, the mixing signal generating module generates the mixing signal according to formula (3-1) or formula (3-2):

[0058] y m =y a +l·h HPF (3-1)

[0059] y m,k =y a,k +l k ·h HPF (3-2)

[0060] Among them, y m is the mixed signal of a single channel, h HPF is a high-pass filter; y m,k is the mixed signal of the kth channel among the K channels.

[0061] The present invention adopts the above solution, which has the following advantages compared with the prior art:

[0062] In the mixing method and mixing device proposed in the present invention, the multimedia signal is introduced into the synthetic signal and error generation signal of the noise reduction control after filtering, and the participation process of the multimedia signal is considered in the weight estimation, thereby solving the influence of the noise reduction control on the multimedia signal and solving the noise reduction cancellation problem when the multimedia signal appears at the same frequency as the noise reduction control signal, ensuring that the multimedia signal can be completely and accurately restored. The mixing method and device proposed in the present invention have a low resource occupation algorithm and are suitable for the engineering implementation of the vehicle-mounted noise reduction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0064] Figure 1 is a flow chart of a single-channel mixing method according to an embodiment of the present invention;

[0065] Figure 2 is a flow chart of a multi-channel mixing method according to another embodiment of the present invention;

[0066] Figure 3 FIG. 4 is a structural block diagram of a sound mixing device according to another embodiment of the present invention.

[0067] in:

[0068] 1. Reference signal generation module; 2. First channel transfer function processing module; 3. Weight estimation module; 4. Synthetic signal generation module; 5. Error signal generation module; 6. Multimedia signal generation module; 7. Low-pass filter processing module; 8. Second channel transfer function processing module; 9. High-pass filter processing module; 10. Mixing signal generation module; 11. Equalization filter processing module. DETAILED DESCRIPTION

[0069] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0070] A mixing method for a vehicle audio system, the mixing method comprising:

[0071] A. Generate a reference signal based on the vehicle engine speed;

[0072] B. generating a synthetic signal according to the reference signal, the multimedia signal after low-pass filtering and the weight coefficient of noise reduction control;

[0073] C. Generate an error signal based on the synthesized signal and the processed multimedia signal; the processed multimedia signal is a multimedia signal that has been processed by low-pass filtering and transfer function filtering in sequence, and the transfer function is a transfer function from a secondary sound source (such as a speaker) to a noise reduction position.

[0074] D. estimating and updating the weight coefficients of the noise reduction control according to the error signal and the reference signal processed by the transfer function;

[0075] E. generating a mixed signal according to the synthesized signal and the multimedia signal after high-pass filtering;

[0076] F. The mixed signal is equalized and then sent to the power amplifier to drive the speaker to produce sound.

[0077] The multimedia signals include but are not limited to navigation, voice, music, telephone and other signals.

[0078] Figure 1 The method of mixing a single-channel noise reduction signal with a vehicle head unit or a power amplifier multimedia signal is shown. The specific process is as follows:

[0079] (1) Generate synthetic signal

[0080] Assume that the transfer function from the secondary sound source to the noise reduction position is h, and the two reference signals generated related to the vehicle engine speed are x0 and x1, with corresponding weights w0 and w1 respectively. The multimedia signal of the car machine or amplifier is l, and the low-pass filter LPF is h LPF , the high pass filter HPF is h HPF . Synthetic signal y a The expression is:

[0081] y a =w0·x0+w1·x1+l·h LPF (1-1)

[0082] (2) Generate error signal

[0083] Assuming the order noise of the engine is d, the expression of the error signal e is:

[0084] e=dy a ·h+l·h LPF ·h (1-2)

[0085] (3) Generate a mixed signal

[0086] The multimedia signal l from the car machine or amplifier is filtered by the high-pass filter HPF and then combined with the synthesized signal y a After mixing, the mixed signal y is formed m , whose expression is:

[0087] y m =y a +l·h HPF

[0088] (4) Generate a balanced mixed signal

[0089] In order to ensure that the frequency response of the low-pass filter and the high-pass filter is flat after superposition, equalization is required. Assume that the equalization filter EQF is h EQF , then the equalized mixed signal y q The expression is:

[0090] y q =y m ·h EQF .

[0091] The error signal generated in step (2) is used to re-estimate the weights in combination with the two reference signals processed by the channel transfer function, and the weights are continuously updated iteratively.

[0092] The single-channel mixing method can be extended to the mixing method of multi-channel active noise reduction and multi-channel multimedia signals. Figure 2 As shown, assuming that there are a total of K channels of vehicle-mounted multi-channel active noise reduction and multi-channel multimedia signals that need to be mixed, the channel numbers are from 1 to K, and the current channel number is k. The specific process is as follows:

[0093] (1) Generate multi-channel synthetic signals

[0094] Assume that the transfer function from the secondary sound source of the current channel k to the noise reduction position is h k The two reference signals generated and associated with the vehicle engine speed are x0 and x1, and the corresponding weights are w 0,k and w 1,k The multimedia signal of the car machine or amplifier is l k , the low pass filter LPF is h LPF , the high pass filter HPF is h HPF . Synthetic signal y a,k The expression is:

[0095] y a,k =w 0,k ·x0+w 1,k ·x1+l k ·h LPF (1-2)

[0096] (2) Generate multi-channel error signals

[0097] Assume that the engine order noise corresponding to the current channel k is d k , the error signal e corresponding to the current channel k k The expression is:

[0098] e k =d k -y a,k ·h k +l k ·h LPF ·h k (2-2)

[0099] (3) Generate multi-channel mixing signals

[0100] Multimedia signal l of the current channel k of the car computer or amplifier k After being filtered by the high-pass filter HPF, the synthesized signal y of the current channel k a,k After mixing, the mixed signal y is formed m,k , whose expression is:

[0101] y m,k =y a,k +l k ·h HPF (2-3)

[0102] (4) Generate a balanced multi-channel mixing signal

[0103] In order to ensure that the frequency response of the low-pass filter and the high-pass filter is flat after superposition, equalization is required. Assume that the equalization filter EQF is h EQF , then the mixed signal y of the current channel k after equalization q,k The expression is:

[0104] y q,k =y m,k ·h EQF (2-4)

[0105] Figure 3 A mixing device for mixing an active noise reduction signal with a multimedia signal in a vehicle audio system is shown. Figure 3 As shown, the mixing device includes: a reference signal generating module 1, a first channel function processing module 2, a weight estimation module 3, a synthetic signal generating module 4, an error signal generating module 5, a multimedia signal generating module 6, a low-pass filtering processing module 7, a second channel function processing module 8, a high-pass filtering processing module 9, a mixing signal generating module 10 and an equalizing filtering processing module 11.

[0106] The reference signal generating module 1 has an input end which is electrically connected to the vehicle control system via a communication line or the like, and is used to obtain the rotation of the vehicle engine and generate a reference signal associated with the vehicle engine speed accordingly.

[0107] The first channel transfer function processing module 2, whose input end is electrically connected to the output end of the reference signal generating module 1, is used to receive the reference signal output by the reference signal generating module 1, and performs channel transfer function filtering on the reference signal and then sends it to the weight estimation module 3. The channel transfer function is a transfer function from the secondary sound source to the noise reduction position.

[0108] A weight estimation module 3, one input end of which is electrically connected to the output end of the first channel transfer function processing module 2, and the other input end of which is electrically connected to the output end of the error signal generating module 5. The weight estimation module 3 is used to receive the reference signal after the channel transfer function filtering process and the generated error signal, and estimate and update the weight coefficient of the noise reduction control;

[0109] The first input terminal of the synthetic signal generating module 4 is electrically connected to the output terminal of the reference signal generating module 1, the second input terminal is electrically connected to the output terminal of the weight estimation module 3, and the third input terminal is electrically connected to the output terminal of the low-pass filtering processing module 7. The synthetic signal generating module 4 is used to receive the reference signal, the updated weight coefficient, and the multimedia signal after low-pass filtering, and generate a synthetic signal accordingly.

[0110] The error signal generating module 5 has one input terminal electrically connected to the output terminal of the synthesized signal generating module 4, and another input terminal electrically connected to the output terminal of the second channel transfer function processing module 8. The error signal generating module 5 is used to generate an error signal according to the synthesized signal and the multimedia signal after low-pass filtering and channel transfer function filtering, and send the error signal to the weight estimation module 3 to update the weight coefficient;

[0111] The multimedia signal generating module 6 is used to generate multimedia signals for the vehicle computer or the power amplifier, including but not limited to: navigation, voice, music, telephone and other signals.

[0112] The low-pass filter processing module 7 has an input end electrically connected to the output end of the multimedia signal generating module 6 , and is used to receive the multimedia signal output by the multimedia signal generating module 6 , and perform low-pass filtering on the multimedia signal and then send it to the synthetic signal generating module 4 .

[0113] The second channel transfer function processing module 8 has an input end electrically connected to the output end of the low-pass filter processing module 7 , and is used for receiving the multimedia signal after low-pass filtering, performing channel transfer function filtering on the multimedia signal, and then sending the multimedia signal to the error signal generating module 5 .

[0114] The high-pass filter processing module 9 has an input end electrically connected to an output end of the multimedia signal generating module 6 , and is used to receive the multimedia signal output by the multimedia signal generating module 6 , and perform high-pass filtering on the multimedia signal and then send it to the mixing signal generating module 10 .

[0115] The mixed signal generating module 10 has one input terminal electrically connected to the output terminal of the synthesized signal generating module 4 and another input terminal electrically connected to the output terminal of the high-pass filtering processing module 9. It is used to generate a mixed signal according to the synthesized signal and the multimedia signal after high-pass filtering.

[0116] The equalization and filtering processing module 11 has an input terminal electrically connected to an output terminal of the mixed signal generating module 10 , and is used to receive the mixed signal output by the mixed signal generating module 10 , and perform equalization and filtering processing on the mixed signal before sending it to the power amplifier.

[0117] The above embodiment is only for illustrating the technical concept and features of the present invention, and is a preferred embodiment. Its purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A mixing method for a vehicle audio system, characterized in that: The mixing method comprises: A. Generate a reference signal based on the vehicle engine speed; B. generating a synthetic signal according to the reference signal, the multimedia signal after filtering and the weight coefficient of noise reduction control; C. generating an error signal according to the synthesized signal and the processed multimedia signal; D. estimating and updating the weight coefficient of noise reduction control according to the error signal; E. generating a mixed signal according to the synthesized signal and the processed multimedia signal; In step B, the synthetic signal is generated according to formula (1-1) or formula (1-2): and a =w0·x0+w1·x1+l·h LPF (1-1) y a,k =w 0,k ·x0+w 1，k ·x1+l k ·h LPF (1-2) Among them, y a is a single-channel synthetic signal, x0 and x1 are two reference signals, and their corresponding weights are w0 and w1, l is a multimedia signal, and h LPF is a low-pass filter; a，k is the composite signal of the kth channel among K channels, and the weights corresponding to the two reference signals x0 and x1 are w 0，k and w 1，k , l k is the multimedia signal corresponding to the kth channel; And / or, in step C, the error signal is generated according to formula (2-1) or formula (2-2): e=d-y a ·h+l·h LPF ·h (2-1) e k =d k -y a,k ·h k +l k ·h LPF ·h k (2-2) Where, e is the error signal of a single channel, d is the order noise of the vehicle engine, and h is the transfer function from the secondary sound source to the noise reduction position; e k is the error signal corresponding to the kth channel, h k is the transfer function from the secondary sound source of the kth channel to the noise reduction position; And / or, in step E, the mixed signal is generated according to formula (3-1) or formula (3-2): y m =y a +l·h HPF (3-1) y m，k =y a，k +l k ·h HPF (3-2) Among them, y m is the mixed signal of a single channel, h HPF is a high-pass filter; m，k is the mixed signal of the kth channel among the K channels.

2. The mixing method according to claim 1, characterized in that: In the step B, the multimedia signal is subjected to low-pass filtering and then the synthesized signal is generated.

3. The mixing method according to claim 1, characterized in that: In the step C, the processed multimedia signal is a multimedia signal that has been processed by low-pass filtering and transfer function filtering in sequence, and the transfer function is a transfer function from a secondary sound source to a noise reduction position.

4. The mixing method according to claim 1, characterized in that: In the step D, the reference signal is first subjected to transfer function filtering processing, and then the weight coefficients of the noise reduction control are estimated and updated according to the error signal and the processed reference signal.

5. The mixing method according to claim 1, characterized in that: In the step E, the multimedia signal is first subjected to high-pass filtering, and then the mixed signal is generated.

6. The mixing method according to claim 1, characterized in that: The mixed signal is sent to the power amplifier after being equalized to drive the speaker to produce sound.

7. A mixing device for a vehicle audio system, characterized in that: include: a reference signal generating module for generating a reference signal associated with a vehicle engine speed; A weight estimation module, which is used to estimate and update the weight coefficient of noise reduction control according to the error signal and the processed reference signal; A multimedia signal generating module, which is used to generate multimedia signals; A synthetic signal generating module, which is used to generate a synthetic signal according to the reference signal, the weight coefficient and the multimedia signal after filtering; and A mixed signal generating module, which is used to generate a mixed signal according to the synthesized signal and the processed multimedia signal; The sound mixing device also includes: an error signal generating module, which is used to generate an error signal according to the synthesized signal and the processed multimedia signal, and send the error signal to the weight estimation module to update the weight coefficient; The synthetic signal generating module generates the synthetic signal according to formula (1-1) or formula (1-2): and a =w0·x0+w1·x1+l·h LPF (1-1) y a,k =w 0，k ·x0+w 1,k ·x1+l k ·h LPF (1-2) Among them, y a is a single-channel synthetic signal, x0 and x1 are two reference signals output by the reference signal generation module, w0 and w1 are weight coefficients output by the weight estimation module, l is a multimedia signal output by the multimedia signal generation module, h LPF is a low-pass filter; a,k is the composite signal of the kth channel among K channels, w 0，k and w 1，k are the weight coefficients output by the weight estimation module, l k A multimedia signal corresponding to the kth channel output by the multimedia signal generating module; And / or, the error signal generating module generates the error signal according to formula (2-1) or formula (2-2): e=d-y a ·h+l·h LPF ·h (2-1) e k =d k -y a,k ·h k +l k ·h LPF ·h k (2-2) Wherein, e is the error signal of a single channel, d is the order noise of the vehicle engine received by the error signal generating module, and h is the transfer function from the secondary sound source to the noise reduction position; e k is the error signal corresponding to the kth channel, h k is the transfer function from the secondary sound source of the kth channel to the noise reduction position; And / or, the mixing signal generating module generates the mixing signal according to formula (3-1) or formula (3-2): y m =y a +l·h HPF (3-1) y m,k =y a，k +l k ·h HPF (3-2) Among them, y m is the mixed signal of a single channel, h HPF is a high-pass filter; m，k is the mixed signal of the kth channel among the K channels.

8. The sound mixing device according to claim 7, characterized in that: The sound mixing device also includes: A first channel transfer function processing module, which is used to receive the reference signal output by the reference signal generating module, perform channel transfer function filtering on the reference signal, and then send it to the weight estimation module; and / or a low-pass filtering processing module, which is used to receive the multimedia signal output by the multimedia signal generating module, perform low-pass filtering on the multimedia signal, and then send it to the synthetic signal generating module; and / or A second channel transfer function processing module is used to receive the multimedia signal after low-pass filtering, perform channel transfer function filtering on the multimedia signal, and then send it to the error signal generating module; and / or a high-pass filter processing module, which is used to receive the multimedia signal output by the multimedia signal generating module, perform high-pass filter processing on the multimedia signal, and then send it to the mixing signal generating module; and / or The equalization and filtering processing module is used to receive the mixed signal output by the mixed signal generating module, perform equalization and filtering processing on the mixed signal, and then send it to the power amplifier.

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