Noise reduction mode switching method and device and noise reduction equipment

Abstract

The invention provides a noise reduction mode switching method and device and noise reduction equipment, and particularly relates to the technical field of audio noise reduction, and the method comprises the steps: obtaining n first zero points and n first poles corresponding to a current system function of a filter in a complex plane, the n second zero points and the n second poles correspond to a target system function of the filter in the complex number plane; the n first zero points, the first poles, the second zero points and the second poles are combined to obtain n zero point groups and n pole groups, each zero point group comprises a first zero point and a second zero point, and each pole group comprises a first pole and a second pole; and performing zero-pole switching according to the n zero point groups and the n pole groups so as to switch the noise reduction equipment from a current noise reduction mode to a target noise reduction mode. According to the invention, not only can the filter be smoothly switched from the current noise reduction mode to the target noise reduction mode, but also the noise reduction mode switching time can be shortened.

Description

Technical Field

[0001] The present disclosure relates to the technical field of audio noise reduction, and in particular to a noise reduction mode switching method, device and noise reduction equipment. Background Art

[0002] In actual use of active noise cancelling headphones, there will be a need to quickly switch the active noise cancellation (ANC) working mode, such as automatically switching the noise cancellation intensity according to the size of the external noise, and switching the noise cancellation-transparency mode according to the user's usage scenario. Generally, the mode switching process is required to be fast and smooth to achieve a better user experience.

[0003] In the related art, the ANC working mode switching is generally performed by fading in and out the DAC, that is, the chip output volume is gradually muted over a period of time, and the ANC mode is switched in the output muted state, and then the output volume is gradually restored over a period of time.

[0004] It is found in the application that the switching time of the switching scheme similar to the above is relatively long. Summary of the invention

[0005] The purpose of the present disclosure is to provide a noise reduction mode switching method, device and noise reduction equipment, so as to solve the technical problem of long switching time of noise reduction modes existing in the related art.

[0006] In a first aspect, an embodiment of the present disclosure provides a noise reduction mode switching method, the method comprising:

[0007] Acquire first zero-pole information and second zero-pole information, wherein the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, and the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device under the current noise reduction mode, and the target system function is used to indicate the system function of the filter under the target noise reduction mode, and n is an integer greater than 1;

[0008] The first zero-pole information and the second zero-pole information are combined to obtain n zero point groups and n pole point groups, wherein each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups, and each pole point group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups;

[0009] Zero-pole switching is performed according to the n zero-point groups and the n pole-point groups to switch the noise reduction device from a current noise reduction mode to a target noise reduction mode.

[0010] In a second aspect, an embodiment of the present disclosure provides a noise reduction mode switching device, the device comprising:

[0011] An information acquisition module, used to acquire first zero-pole information and second zero-pole information, wherein the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, and the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device under the current noise reduction mode, and the target system function is used to indicate the system function of the filter under the target noise reduction mode, and n is an integer greater than 1;

[0012] an information combination module, configured to combine the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole point groups, wherein each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups, and each pole point group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups;

[0013] A mode switching module is used to perform zero-pole switching according to the n zero point groups and the n pole point groups, so as to switch the noise reduction device from a current noise reduction mode to a target noise reduction mode.

[0014] In a third aspect, the present disclosure provides a noise reduction device, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the steps of the method described in the first aspect when executed by the processor.

[0015] In a fourth aspect, the present disclosure provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0016] In the present disclosure, the zero-pole points corresponding to the coefficient function of the filter in the current noise reduction mode and the zero-pole points corresponding to the coefficient function in the target noise reduction mode are obtained, and zero-point groups and pole groups are constructed accordingly to perform zero-pole switching, so as to realize the smooth switching of the filter from the current noise reduction mode to the target noise reduction mode, avoid the time loss caused by the disorderly switching of the filter, and effectively shorten the switching time of the noise reduction mode of the noise reduction device. Furthermore, it can support the switching of noise reduction modes in the non-muted state to avoid interrupting music / calls. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flowchart of a noise reduction mode switching method provided in an embodiment of the present application;

[0018] Figure 2 is a signal path block diagram of a noise reduction device provided in an embodiment of the present application;

[0019] Figure 3 is a structural schematic diagram of an active noise reduction filter provided in an embodiment of the present application;

[0020] Figure 4 It is a frequency response diagram of a filter provided in an embodiment of the present application under different filtering parameters;

[0021] Figure 5 It is a distribution diagram of different zero points corresponding to different filtering parameters of a filter on the positive half axis of an imaginary number provided in an embodiment of the present application;

[0022] Figure 6 It is a schematic diagram of a noise reduction mode switching process of a filter provided by an embodiment of the present application with or without zero-pole pairing;

[0023] Figure 7 It is a structural schematic diagram of a noise reduction mode switching device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0025] The present disclosure provides a method for switching a noise reduction mode. Figure 1 As shown, the method includes:

[0026] Step 101: Obtain first zero-pole information and second zero-pole information.

[0027] Among them, the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device under the current noise reduction mode, and the target system function is used to indicate the system function of the filter under the target noise reduction mode, and n is an integer greater than 1.

[0028] The current noise reduction mode is one of multiple noise reduction modes supported by the noise reduction device, and the target noise reduction mode is another one of the multiple noise reduction modes;

[0029] The multiple noise reduction modes include at least two of the following:

[0030] No noise reduction mode, different gears corresponding to different noise reduction intensities in graded noise reduction mode, transparency mode-ambient sound, transparency mode-voice, specific environment mode-wind noise, specific environment mode-airport.

[0031] Specifically, when the noise reduction device is in the non-noise reduction mode, it can be understood that the noise reduction device has turned off the noise reduction function. At this time, external sounds and the audio played through the noise reduction device can be heard by the user. It is usually used in a quiet environment (such as a library) or when the user wants to hear the surrounding sounds (such as when the user is crossing the road).

[0032] When the noise reduction device is in the graded noise reduction mode, it can be understood that the noise reduction device has enabled the active noise reduction function and provides multiple gears corresponding to multiple noise reduction intensities. Users can select different gears (such as strong, medium, and weak) according to the intensity of ambient noise, such as selecting the graded noise reduction mode-weak gear in a quiet indoor environment, and selecting the graded noise reduction mode-strong gear in a noisy outdoor environment; at this time, the audio played by the noise reduction device can be heard by the user, while the external sound cannot be heard by the user or the volume of the external sound is significantly reduced.

[0033] When the noise reduction device is in the transparent transmission mode - ambient sound, it can be understood that the noise reduction device will enhance the sound of the surrounding environment, allowing users to clearly hear traffic, conversations or other important sounds, so that when users are walking or riding bicycles on the street, it can help users perceive the conditions of the surrounding environment and avoid potential dangers.

[0034] Similarly, when the noise reduction device is in the transparent transmission mode - voice, it can be understood that the noise reduction device will focus on enhancing the human voice, so that the user can more easily hear other people's speech while listening to music, so as to support the user to communicate with others in social occasions or office environments without taking off the headphones.

[0035] When the noise reduction device is in a specific environment mode - wind noise, it can be understood that the noise reduction device has enabled the adaptive noise reduction function. The noise reduction device is mainly used to reduce the interference of wind noise on the audio experience. It is usually used during outdoor activities, such as cycling, running or at the beach.

[0036] When the noise reduction device is in a specific environment mode - airport, it can be understood that the noise reduction device has enabled the adaptive noise reduction function. The noise reduction device is mainly used to reduce the interference of background noise (such as crowd conversations, aircraft takeoff and landing, etc.) to help users better enjoy music or make calls.

[0037] It should be noted that the above examples are only used to illustrate several noise reduction modes that the noise reduction device may support. In application, the noise reduction modes supported by the noise reduction device can be adaptively increased or decreased according to actual conditions. This application does not limit the specific noise reduction modes indicated by the current noise reduction mode and the target noise reduction mode.

[0038] Specifically, by factorizing the system function of the filter in the noise reduction device in the current noise reduction mode according to zeros and poles, several first zeros and several first poles corresponding to the system function of the filter in the current noise reduction mode in the complex plane can be obtained.

[0039] Similarly, by factorizing the system function of the filter in the noise reduction device in the target noise reduction mode according to zeros and poles, several second zeros and several second poles corresponding to the system function of the filter in the target noise reduction mode in the complex plane can be obtained.

[0040] The zero point corresponding to the filter parameter of the system function of the filter in the complex plane can be understood as: the point corresponding to the solution that makes the numerator polynomial of the system function of the filter equal to zero in the complex plane;

[0041] The poles corresponding to the filter parameters of the system function of the filter in the complex plane can be understood as the points corresponding to the solutions that make the denominator polynomial of the system function of the filter equal to zero in the complex plane.

[0042] The noise reduction device may be any electronic device with an active noise reduction function, such as an active noise reduction headset.

[0043] Without loss of generality, when the noise reduction device is an active noise reduction headset, the signal path block diagram of the noise reduction device can be as follows: Figure 2 As shown, the noise reduction device includes: a feed forward microphone (FF mic), a feedback microphone (FB mic), an analog to digital converter (ADC), a downsampler (Decimator), an active noise cancellation filter (ANC Filter), an interpolator (interpolator), a Sigma-Delta Modulator (SDM), and a digital to analog converter (DAC).

[0044] The signal flow process of the above-mentioned noise reduction device is as follows: the feedforward microphone captures the noise signal in the environment, and the feedback microphone captures the sound inside the headphones or noise reduction device, including the sound heard by the user and the residual noise; the captured analog signal (from the feedforward microphone and the feedback microphone) is converted into a digital signal through an analog-to-digital converter, and the sampling rate of the digital signal is reduced to an appropriate level through a downsampler (to reduce the processing burden and storage requirements), and the downsampled digital signal will be input into the active noise cancellation filter to generate an anti-phase signal based on the captured noise signal, thereby offsetting the noise.

[0045] The interpolator interpolates the downsampled signal to generate a higher resolution signal, which is then fed into a Σ-Δ modulator to convert the signal into a format suitable for processing by a digital-to-analog converter. Finally, the digital-to-analog converter converts the digital signal into an analog signal for playback through speakers or headphones.

[0046] The filter in the aforementioned noise reduction device is an active noise cancellation filter in this example. Generally speaking, an active noise cancellation filter (ANC filter) is generally designed using a multi-stage cascaded second-order infinite impulse response (IIR) filter structure. The structural block diagram of the ANC filter can be shown as follows: Figure 3 As shown, Figure 3 The ANC filter shown in FIG. 1 is formed by connecting N IIR filters in series, where N is an integer greater than or equal to 1.

[0047] Factoring the system function according to the zeros and poles can obtain the zeros and poles corresponding to the filter in the complex plane. Generally speaking, a second-order filter corresponds to a pair of zeros and a pair of poles in the complex plane. In other words, generally speaking, if a second-order filter is formed by connecting N IIR filters in series, it corresponds to N pairs of zeros and N pairs of poles in the complex plane.

[0048] Step 102: Combine the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole point groups.

[0049] Among them, each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups; each pole group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups.

[0050] It should be noted that the above-mentioned combination process can be carried out in a random combination manner to quickly output n zero point groups and n pole groups; or it can be carried out by first traversing all possible combination strategies, and then selecting the optimal combination strategy (based on which the time spent on switching the noise reduction mode is the shortest) as n zero point groups and n pole groups, so as to shorten the time spent on switching the noise reduction mode while avoiding the problem of filter instability during the noise reduction mode switching process, and at the same time support noise reduction mode switching in a non-muted state to avoid interruptions to music / calls.

[0051] In one example, if the first zero-pole information is set to include the first zero point A_a1, the first zero point A_a2, the first pole point A_b1, and the first pole point A_b2, and the second zero-pole information includes the second zero point B_a1, the second zero point B_a2, the second pole point B_b1, and the second pole point B_b2, a random combination method is adopted to obtain the zero point group and the pole group;

[0052] Then, two zero point groups formed by combining the first zero-pole information and the second zero-pole information may be:

[0053] Zero point group [A_a1, B_a1] and zero point group [A_a2, B_a2];

[0054] or,

[0055] Zero point group [A_a1, B_a2] and zero point group [A_a2, B_a1];

[0056] The two pole groups formed by combining the first zero-pole information and the second zero-pole information may be:

[0057] The pole group [A_b1, B_b1] and the pole group [A_b2, B_b2];

[0058] or,

[0059] The pole group [A_b1, B_b2] and the pole group [A_b2, B_b1].

[0060] Step 103: Perform zero-pole switching according to the n zero point groups and the n pole point groups to switch the noise reduction device from a current noise reduction mode to a target noise reduction mode.

[0061] In the present disclosure, by obtaining the zero poles corresponding to the coefficient function of the filter in the current noise reduction mode and the zero poles corresponding to the coefficient function in the target noise reduction mode, and constructing zero point groups and pole groups accordingly to perform zero-pole switching, the filter can be smoothly switched from the current noise reduction mode to the target noise reduction mode, avoiding time loss caused by disordered switching of the filter, and effectively shortening the noise reduction mode switching time of the noise reduction device.

[0062] In one embodiment, the combining of the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole groups includes:

[0063] The first zero-pole information and the second zero-pole information are combined to obtain m candidate combination strategies, wherein each candidate combination strategy includes n candidate zero point groups and n candidate pole groups, each candidate zero point group includes a first zero point and a second zero point, different first zero points are located in different candidate zero point groups, different second zero points are located in different candidate zero point groups, each candidate pole group includes a first pole and a second pole, different first poles are located in different candidate pole groups, different second poles are located in different candidate pole groups, and m is the factorial of n;

[0064] Among the m candidate combination strategies, a switching parameter corresponding to each candidate combination strategy is calculated, wherein the switching parameter is the sum of multiple zero point distances and multiple pole distances in the corresponding candidate combination strategy, the zero point distance is the distance between the first zero point and the second zero point in the corresponding candidate zero point group of the corresponding candidate combination strategy in the complex plane, and the pole distance is the distance between the first pole and the second pole in the corresponding candidate pole group of the corresponding candidate combination strategy in the complex plane;

[0065] Among the m candidate combination strategies, the candidate combination strategy corresponding to the minimum switching parameter is determined as the target combination strategy, and the candidate zero point group and the candidate pole point group included in the target combination strategy are respectively determined as the zero point group and the pole point group.

[0066] The switching parameter is used to indicate the time consumption for switching the noise reduction mode according to the corresponding candidate combination strategy, wherein the smaller the switching parameter is, the less time consumption for switching the noise reduction mode according to the corresponding candidate combination strategy is.

[0067] In this embodiment, by traversing all possible combinations of the first zero-pole information and the second zero-pole information, m candidate combination strategies are obtained, and then the switching parameters corresponding to each candidate combination strategy are calculated, and the candidate combination strategy corresponding to the smallest switching parameter is determined as the target combination strategy, that is, determined as the optimal combination strategy, thereby obtaining n zero point groups and n pole groups for zero-pole switching, which can shorten the time of subsequent zero-pole switching and avoid the risk of filter instability (such as the situation where the pole crosses the unit circle during mode switching) introduced by unreasonable candidate combination strategies.

[0068] In one embodiment, the values ​​of the plurality of filter parameters of the filter in the current system function are different from the values ​​of the plurality of filter parameters of the filter in the target system function;

[0069] When zero-pole switching is performed according to the n zero point groups and the n pole groups, the first zero point in each zero point group is switched to the second zero point in the zero point group, and the first pole in each pole group is switched to the second pole in the pole group, so that the values ​​of multiple filtering parameters of the filter in the current system function are switched to the values ​​of multiple filtering parameters of the filter in the target system function, so that the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode.

[0070] Further, the performing zero-pole switching according to the n zero point groups and the n pole groups includes:

[0071] Interpolating between a first zero point and a second zero point included in each of the zero point groups to obtain a zero point switching point set corresponding to each of the zero point groups;

[0072] Interpolating between a first pole and a second pole included in each of the pole groups to obtain a pole switching point set corresponding to each of the pole groups;

[0073] According to the zero point switching point set corresponding to each of the zero point groups and the pole switching point set corresponding to each of the pole point groups, zero-pole switching is performed on the n zero point groups and the n pole point groups respectively.

[0074] When the first zero point of each zero point group is switched to the second zero point of the zero point group, and the first pole of each pole group is switched to the second pole of the pole group, multiple zero point switching points / pole switching points for transition in the switching process are obtained by interpolation, so that the switching process from the first zero point to the second zero point in the same zero point group is divided into multiple stages by using multiple zero point switching points, and the switching process from the first pole to the second pole in the same pole group is divided into multiple stages by using multiple pole switching points, so that the above-mentioned zero-pole switching is smoother, and the change of the audio played by the noise reduction device when the noise reduction mode is switched is smoother, bringing a better listening experience to users.

[0075] Exemplarily, for each zero point group, interpolation is performed within a line segment with the first zero point and the second zero point included in the zero point group as endpoints, so that the path from the first zero point included in the zero point group to the second zero point included in the zero point group can be made the shortest, and the overall time consumption of noise reduction mode switching can be reduced to a certain extent.

[0076] Similarly, for each pole group, interpolation is performed within a line segment with the first pole and the second pole included in the pole group as endpoints, so that the path from the first pole included in the pole group to the second pole included in the pole group can be the shortest.

[0077] Furthermore, interpolating between the first zero point and the second zero point included in each of the zero point groups to obtain a zero point switching point set corresponding to each of the zero point groups includes:

[0078] Calculate the zero point switching step length of each zero point group according to the preset parameter, wherein the zero point switching step length is the ratio of the distance between the first zero point and the second zero point included in the corresponding zero point group in the complex plane and the preset parameter;

[0079] According to the zero point switching step length of each zero point group, linear interpolation is performed between the first zero point and the second zero point included in each zero point group to obtain a zero point switching point set corresponding to each zero point group, wherein the distance between any two adjacent points in the zero point switching point set is the distance indicated by the corresponding zero point switching step length;

[0080] The interpolation is performed between the first pole and the second pole included in each pole group to obtain a pole switching point set corresponding to each pole group, including:

[0081] Calculating a pole switching step length of each pole group according to the preset parameter, wherein the pole switching step length is a ratio of a distance between a first pole and a second pole included in the corresponding pole group in the complex plane to the preset parameter;

[0082] According to the pole switching step of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain a pole switching point set corresponding to each pole group, wherein the distance between any two adjacent points in the pole switching point set is the distance indicated by the corresponding pole switching step.

[0083] Specifically, according to the zero point switching point set corresponding to each of the zero point groups and the pole switching point set corresponding to each of the pole point groups, zero-pole switching is performed on the n zero point groups and the n pole point groups respectively, including:

[0084] In the complex plane, taking the first zero point included in each zero point group as the starting point, the second zero point included in each zero point group as the end point, and the zero point switching point set corresponding to each zero point group as the moving path, the zero point moving operation corresponding to each zero point group is performed;

[0085] In the complex plane, taking the first pole included in each pole group as the starting point, the second pole included in each pole group as the end point, and the pole switching point set corresponding to each pole group as the moving path, performing the pole moving operation corresponding to each pole group;

[0086] The zero point moving operation corresponding to any zero point group and the pole point moving operation corresponding to any pole point group are synchronous operations.

[0087] By means of linear interpolation, the switching steps of different zero point groups and the switching steps of different pole groups are unified, thereby ensuring the synchronous execution of the switching operations of different zero point groups and the switching operations of different pole groups.

[0088] The number of switching steps may be understood as the value indicated by the aforementioned preset parameters, and the user may adaptively adjust the preset parameters according to actual needs.

[0089] Without loss of generality, it can be set that when step-by-step switching is performed according to the above-mentioned switching steps, the switching interval of each step is a set value, so as to utilize the flexible and adjustable switching step setting to support different switching smoothness requirements, for example: setting a larger switching step to provide users with a smoother noise reduction mode switching experience and reduce the interference of noise reduction mode switching on users' normal listening; setting a smaller switching step to reduce unnecessary operating overhead while ensuring the smoothness of the switching process, and at the same time shortening the overall time consumption of noise reduction mode switching.

[0090] Take the filter in the noise reduction device formed by two second-order filters in series as an example. Figure 4 As shown, the current noise reduction mode is set to the graded noise reduction mode-strong gear, the target noise reduction mode is the transparent mode, the multiple filtering parameters of the filter in the current system function of the current noise reduction mode are collectively referred to as A, and the multiple filtering parameters of the filter in the target system function of the target noise reduction mode are collectively referred to as B. The switching process from A to B is Figure 4 It can be seen that the zero point of A moves to the zero point of B in q steps, and the pole of A moves to the pole of B in q steps. Each step moves 1 / q of the spatial distance. The parameters of the two second-order IIR filters are switched synchronously, and q can be understood as the aforementioned preset parameter, that is, the number of switching steps.

[0091] Among them, the zero point distribution diagram of A and B on the positive semi-axis of imaginary numbers can be shown as follows Figure 5 As shown, A_z1 and A_z2 represent the two zero points of A on the positive semi-axis of imaginary numbers (in Figure 5 In the figure, the hollow circles represent the two first zeros), B_z1 and B_z2 represent the two zeros of B on the positive semi-axis of the imaginary number (in Figure 5 In the figure, the solid circles represent the two second zero points. Figure 5 It can be found that the moving distance from A_z1 to B_z2 is obviously shorter than that from A_z1 to B_z2, and the moving distance from A_z2 to B_z1 is also shorter than that from A_z1 to B_z1;

[0092] Therefore, the total path of zero point switching by forming A_z1 and B_z2 into one zero point group and forming A_z2 and B_z1 into another zero point group is significantly shorter than the total path of zero point switching by forming A_z1 and B_z1 into one zero point group and forming A_z2 and B_z2 into another zero point group;

[0093] That is to say, A_z1 and B_z2 form a zero point group, and A_z2 and B_z1 form another zero point group, so that the moving distance of the zero point parameter can be minimized during the process of switching from A to B.

[0094] like Figure 6 As shown, assuming q=4096, the adjustment step of each zero group is the ratio of the distance between the two zeros in the zero group to q, the adjustment step of each pole group is the ratio of the distance between the two poles in the pole group to q, and the adjustment interval of each step is 60us. A 1000Hz sine wave is used as the filter input. By observing the output curve of the filter during the parameter adjustment process (light gray curve), it can be seen that the switching process becomes significantly smoother after zero-pole pairing.

[0095] In one embodiment, the parameter value of the preset parameter is positively correlated with the audio quality of the audio currently transmitted by the noise reduction device, and the parameter value of the preset parameter is less than the set parameter threshold.

[0096] Based on the above settings, the noise reduction device is supported to adaptively adjust the preset parameters based on the audio quality of the currently transmitted audio, so as to further reduce the interference of the noise reduction mode switching on the user's normal listening.

[0097] Specifically, before executing the noise reduction mode switching, the noise reduction device monitors the audio quality of the currently transmitted audio. If it is monitored that the audio quality of the currently transmitted audio is high (such as higher bit rate, higher sampling rate), the first parameter value is assigned to the preset parameter; if it is monitored that the audio quality of the currently transmitted audio is relatively general (such as lower bit rate, lower sampling rate), the second parameter value is assigned to the preset parameter; wherein the first parameter value is greater than the second parameter value, so as to set a larger switching step for high-quality audio, so as to improve the smoothness of the noise reduction mode switching process and reduce the interference of the noise reduction mode switching on the user's normal listening; and set a smaller switching step for low-quality audio, so as to reduce the interference of the noise reduction mode switching on the user's normal listening and shorten the overall time of the noise reduction mode switching as much as possible.

[0098] In one embodiment, when the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode, the noise reduction device is in an unmuted state.

[0099] In this embodiment, when the noise reduction mode is smoothly switched based on zero-pole switching, the noise reduction device is set to an unmuted state to avoid interruption of the original listening / calling action by the noise reduction mode switching, saving unnecessary time caused by executing muting and unmuting operations, and avoiding interference with the user's current listening / calling action, thereby bringing a better user experience to the user.

[0100] See also Figure 7 , Figure 7 A noise reduction mode switching device is provided in an embodiment of the present disclosure. Figure 7 As shown, the noise reduction mode switching device 700 includes:

[0101] The information acquisition module 701 is used to acquire first zero-pole information and second zero-pole information, wherein the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, and the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device in the current noise reduction mode, and the target system function is used to indicate the system function of the filter in the target noise reduction mode, and n is an integer greater than 1;

[0102] an information combining module 702, configured to combine the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole point groups, wherein each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups, and each pole point group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups;

[0103] The mode switching module 703 is used to perform zero-pole switching according to the n zero point groups and the n pole point groups, so as to switch the noise reduction device from the current noise reduction mode to the target noise reduction mode.

[0104] In one embodiment, the values ​​of the plurality of filter parameters of the filter in the current system function are different from the values ​​of the plurality of filter parameters of the filter in the target system function;

[0105] When zero-pole switching is performed according to the n zero point groups and the n pole groups, the first zero point in each zero point group is switched to the second zero point in the zero point group, and the first pole in each pole group is switched to the second pole in the pole group, so that the values ​​of multiple filtering parameters of the filter in the current system function are switched to the values ​​of multiple filtering parameters of the filter in the target system function, so that the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode.

[0106] In one embodiment, the mode switching module 703 includes:

[0107] A zero point interpolation unit, used for interpolating between a first zero point and a second zero point included in each of the zero point groups, so as to obtain a zero point switching point set corresponding to each of the zero point groups;

[0108] A pole interpolation unit, used for interpolating between a first pole and a second pole included in each pole group, so as to obtain a pole switching point set corresponding to each pole group;

[0109] A switching unit is used to perform zero-pole switching on the n zero point groups and the n pole point groups respectively according to the zero point switching point set corresponding to each of the zero point groups and the pole switching point set corresponding to each of the pole point groups.

[0110] In one embodiment, the zero-point interpolation unit is specifically used for:

[0111] Calculate the zero point switching step length of each zero point group according to the preset parameter, wherein the zero point switching step length is the ratio of the distance between the first zero point and the second zero point included in the corresponding zero point group in the complex plane and the preset parameter;

[0112] According to the zero point switching step length of each zero point group, linear interpolation is performed between the first zero point and the second zero point included in each zero point group to obtain a zero point switching point set corresponding to each zero point group, wherein the distance between any two adjacent points in the zero point switching point set is the distance indicated by the corresponding zero point switching step length;

[0113] The pole interpolation unit is specifically used for:

[0114] Calculating a pole switching step length of each pole group according to the preset parameter, wherein the pole switching step length is a ratio of a distance between a first pole and a second pole included in the corresponding pole group in the complex plane to the preset parameter;

[0115] According to the pole switching step of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain a pole switching point set corresponding to each pole group, wherein the distance between any two adjacent points in the pole switching point set is the distance indicated by the corresponding pole switching step.

[0116] In one embodiment, the switching unit is specifically used for:

[0117] In the complex plane, taking the first zero point included in each zero point group as the starting point, the second zero point included in each zero point group as the end point, and the zero point switching point set corresponding to each zero point group as the moving path, the zero point moving operation corresponding to each zero point group is performed;

[0118] In the complex plane, taking the first pole included in each pole group as the starting point, the second pole included in each pole group as the end point, and the pole switching point set corresponding to each pole group as the moving path, performing the pole moving operation corresponding to each pole group;

[0119] The zero point moving operation corresponding to any zero point group and the pole point moving operation corresponding to any pole point group are synchronous operations.

[0120] In one embodiment, the current noise reduction mode is one of a plurality of noise reduction modes, and the target noise reduction mode is another of the plurality of noise reduction modes;

[0121] The multiple noise reduction modes include at least two of the following:

[0122] No noise reduction mode, different gears corresponding to different noise reduction intensities in graded noise reduction mode, transparency mode-ambient sound, transparency mode-voice, specific environment mode-wind noise, specific environment mode-airport.

[0123] In one embodiment, the information combination module 702 is specifically used to:

[0124] The first zero-pole information and the second zero-pole information are combined to obtain m candidate combination strategies, wherein each candidate combination strategy includes n candidate zero point groups and n candidate pole groups, each candidate zero point group includes a first zero point and a second zero point, different first zero points are located in different candidate zero point groups, different second zero points are located in different candidate zero point groups, each candidate pole group includes a first pole and a second pole, different first poles are located in different candidate pole groups, different second poles are located in different candidate pole groups, and m is the factorial of n;

[0125] Among the m candidate combination strategies, a switching parameter corresponding to each candidate combination strategy is calculated, wherein the switching parameter is the sum of multiple zero point distances and multiple pole distances in the corresponding candidate combination strategy, the zero point distance is the distance between the first zero point and the second zero point in the corresponding candidate zero point group of the corresponding candidate combination strategy in the complex plane, and the pole distance is the distance between the first pole and the second pole in the corresponding candidate pole group of the corresponding candidate combination strategy in the complex plane;

[0126] Among the m candidate combination strategies, the candidate combination strategy corresponding to the minimum switching parameter is determined as the target combination strategy, and the candidate zero point group and the candidate pole point group included in the target combination strategy are respectively determined as the zero point group and the pole point group.

[0127] In one embodiment, the parameter value of the preset parameter is positively correlated with the audio quality of the audio currently transmitted by the noise reduction device, and the parameter value of the preset parameter is less than the set parameter threshold.

[0128] In one embodiment, when the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode, the noise reduction device is in an unmuted state.

[0129] The noise reduction mode switching device 700 provided in the embodiment of the present disclosure can implement each process in the above-mentioned noise reduction mode switching method embodiment, and will not be described again here to avoid repetition.

[0130] According to an embodiment of the present disclosure, the present disclosure also provides a noise reduction device.

[0131] Figure 2 A schematic block diagram of an example noise reduction device that can be used to implement an embodiment of the present disclosure is shown. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit implementations of the present disclosure described and / or claimed herein.

[0132] The noise reduction device provided in the embodiment of the present disclosure can implement each process in the above-mentioned noise reduction mode switching method embodiment, and will not be described again here to avoid repetition.

[0133] The present application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above Figure 1 The various processes of the method embodiment shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0134] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0135] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A noise reduction mode switching method, characterized in that: The method comprises: Acquire first zero-pole information and second zero-pole information, wherein the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, and the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device under the current noise reduction mode, and the target system function is used to indicate the system function of the filter under the target noise reduction mode, and n is an integer greater than 1; The first zero-pole information and the second zero-pole information are combined to obtain n zero point groups and n pole point groups, wherein each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups, and each pole point group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups; Zero-pole switching is performed according to the n zero-point groups and the n pole-point groups to switch the noise reduction device from a current noise reduction mode to a target noise reduction mode.

2. The method according to claim 1, characterized in that The values ​​of the plurality of filter parameters of the filter in the current system function are different from the values ​​of the plurality of filter parameters of the filter in the target system function; When zero-pole switching is performed according to the n zero point groups and the n pole groups, the first zero point in each zero point group is switched to the second zero point in the zero point group, and the first pole in each pole group is switched to the second pole in the pole group, so that the values ​​of multiple filtering parameters of the filter in the current system function are switched to the values ​​of multiple filtering parameters of the filter in the target system function, so that the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode.

3. The method according to claim 2, characterized in that The performing zero-pole switching according to the n zero point groups and the n pole groups comprises: Interpolating between a first zero point and a second zero point included in each of the zero point groups to obtain a zero point switching point set corresponding to each of the zero point groups; Interpolating between a first pole and a second pole included in each of the pole groups to obtain a pole switching point set corresponding to each of the pole groups; According to the zero point switching point set corresponding to each of the zero point groups and the pole switching point set corresponding to each of the pole point groups, zero-pole switching is performed on the n zero point groups and the n pole point groups respectively.

4. The method according to claim 3, characterized in that: The interpolation is performed between the first zero point and the second zero point included in each of the zero point groups to obtain a zero point switching point set corresponding to each of the zero point groups, including: Calculate the zero point switching step length of each zero point group according to the preset parameter, wherein the zero point switching step length is the ratio of the distance between the first zero point and the second zero point included in the corresponding zero point group in the complex plane and the preset parameter; According to the zero point switching step length of each zero point group, linear interpolation is performed between the first zero point and the second zero point included in each zero point group to obtain a zero point switching point set corresponding to each zero point group, wherein the distance between any two adjacent points in the zero point switching point set is the distance indicated by the corresponding zero point switching step length; The interpolation is performed between the first pole and the second pole included in each pole group to obtain a pole switching point set corresponding to each pole group, including: Calculating a pole switching step length of each pole group according to the preset parameter, wherein the pole switching step length is a ratio of a distance between a first pole and a second pole included in the corresponding pole group in the complex plane to the preset parameter; According to the pole switching step of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain a pole switching point set corresponding to each pole group, wherein the distance between any two adjacent points in the pole switching point set is the distance indicated by the corresponding pole switching step.

5. The method according to claim 3, characterized in that: According to the zero point switching point set corresponding to each of the zero point groups and the pole switching point set corresponding to each of the pole point groups, zero-pole switching is performed on the n zero point groups and the n pole point groups respectively, including: In the complex plane, taking the first zero point included in each zero point group as the starting point, the second zero point included in each zero point group as the end point, and the zero point switching point set corresponding to each zero point group as the moving path, the zero point moving operation corresponding to each zero point group is performed; In the complex plane, taking the first pole included in each pole group as the starting point, the second pole included in each pole group as the end point, and the pole switching point set corresponding to each pole group as the moving path, performing the pole moving operation corresponding to each pole group; The zero point moving operation corresponding to any zero point group and the pole point moving operation corresponding to any pole point group are synchronous operations.

6. The method according to claim 1, characterized in that The current noise reduction mode is one of multiple noise reduction modes, and the target noise reduction mode is another one of the multiple noise reduction modes; The multiple noise reduction modes include at least two of the following: No noise reduction mode, different gears corresponding to different noise reduction intensities in graded noise reduction mode, transparency mode-ambient sound, transparency mode-voice, specific environment mode-wind noise, specific environment mode-airport.

7. The method according to claim 1, characterized in that The combining the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole groups includes: The first zero-pole information and the second zero-pole information are combined to obtain m candidate combination strategies, wherein each candidate combination strategy includes n candidate zero point groups and n candidate pole groups, each candidate zero point group includes a first zero point and a second zero point, different first zero points are located in different candidate zero point groups, different second zero points are located in different candidate zero point groups, each candidate pole group includes a first pole and a second pole, different first poles are located in different candidate pole groups, different second poles are located in different candidate pole groups, and m is the factorial of n; Among the m candidate combination strategies, a switching parameter corresponding to each candidate combination strategy is calculated, wherein the switching parameter is the sum of multiple zero point distances and multiple pole distances in the corresponding candidate combination strategy, the zero point distance is the distance between the first zero point and the second zero point in the corresponding candidate zero point group of the corresponding candidate combination strategy in the complex plane, and the pole distance is the distance between the first pole and the second pole in the corresponding candidate pole group of the corresponding candidate combination strategy in the complex plane; Among the m candidate combination strategies, the candidate combination strategy corresponding to the minimum switching parameter is determined as the target combination strategy, and the candidate zero point group and the candidate pole point group included in the target combination strategy are respectively determined as the zero point group and the pole point group.

8. The method according to claim 4, characterized in that The parameter value of the preset parameter is positively correlated with the audio quality of the audio currently transmitted by the noise reduction device, and the parameter value of the preset parameter is less than the set parameter threshold.

9. The method according to claim 1, characterized in that: When the noise reduction device is switched from the current noise reduction mode to the target noise reduction mode, the noise reduction device is in an unmuted state.

10. A noise reduction mode switching device, characterized in that: The device comprises: An information acquisition module, used to acquire first zero-pole information and second zero-pole information, wherein the first zero-pole information includes n first zeros and n first poles corresponding to the current system function in the complex plane, and the second zero-pole information includes n second zeros and n second poles corresponding to the target system function in the complex plane, the current system function is used to indicate the system function of the filter in the noise reduction device under the current noise reduction mode, and the target system function is used to indicate the system function of the filter under the target noise reduction mode, and n is an integer greater than 1; an information combination module, configured to combine the first zero-pole information and the second zero-pole information to obtain n zero point groups and n pole point groups, wherein each zero point group includes a first zero point and a second zero point, different first zero points are located in different zero point groups, and different second zero points are located in different zero point groups, and each pole point group includes a first pole and a second pole, different first poles are located in different pole groups, and different second poles are located in different pole groups; A mode switching module is used to perform zero-pole switching according to the n zero point groups and the n pole point groups, so as to switch the noise reduction device from a current noise reduction mode to a target noise reduction mode.

11. A noise reduction device, characterized in that: Used to execute the noise reduction mode switching method as described in any one of claims 1-9.

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