A method, apparatus and device for switching noise reduction modes

Abstract

This application provides a noise reduction mode switching method, apparatus, and noise reduction device, specifically relating to the technical field of audio noise reduction. The method includes: obtaining n first zeros and n first poles corresponding to the current system function of a filter in the complex plane, and n second zeros and n second poles corresponding to the target system function of the filter in the complex plane; combining the n first zeros, first poles, second zeros, and second poles to obtain n zero-point groups and n pole groups, wherein each zero-point group includes one first zero and one second zero, and each pole group includes one first pole and one second pole; performing zero-pole switching according to the n zero-point groups and the n pole groups to switch the noise reduction device from the current noise reduction mode to the target noise reduction mode. This disclosure not only enables the filter to smoothly switch from the current noise reduction mode to the target noise reduction mode, but also shortens the noise reduction mode switching time.

Description

Technical Field

[0001] This disclosure relates to the technical field of audio noise reduction, specifically to a noise reduction mode switching method, apparatus, and noise reduction device. Background Technology

[0002] In actual use, active noise-canceling headphones require quick switching of active noise cancellation (ANC) modes. For example, automatic switching of noise cancellation intensity based on the level of external noise, and switching between noise cancellation and transparency modes based on the user's usage scenario. Generally, the mode switching process needs to be fast and smooth to achieve a better user experience.

[0003] In related technologies, ANC working mode switching is generally performed using a fade-in / fade-out DAC method. That is, the chip output volume is gradually muted over a period of time, and ANC mode switching is performed while the output is muted. Then, the output volume is gradually restored over a period of time.

[0004] During application, it was found that the switching time for switching schemes like the one described above is relatively long. Summary of the Invention

[0005] The purpose of this disclosure is to provide a noise reduction mode switching method, apparatus, and noise reduction device to solve the technical problem of long switching time for noise reduction modes in related technologies.

[0006] In a first aspect, embodiments of this disclosure provide 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, wherein 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;

[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. Each zero-point group includes a first zero and a second zero. Different first zeros are located in different zero-point groups, and different second zeros are located in different zero-point groups. Each pole-point group includes a first pole and a second pole. Different first poles are located in different pole-point groups, and different second poles are located in different pole-point groups.

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

[0010] Secondly, embodiments of this disclosure provide a noise reduction mode switching device, the device comprising:

[0011] The information acquisition module is used to acquire first zero-pole information and second zero-pole information. 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 in the current noise reduction mode. The target system function is used to indicate the system function of the filter in the target noise reduction mode. n is an integer greater than 1.

[0012] The information combination module is used to combine the first zero-pole information and the second zero-pole information to obtain n zero-point groups and n pole groups. Each zero-point group includes a first zero and a second zero, with different first zeros located in different zero-point groups and different second zeros located in different zero-point groups. Each pole group includes a first pole and a second pole, with different first poles located in different pole groups and different second poles located in different pole groups.

[0013] The mode switching module is used to perform zero-pole switching based on the n zero-point groups and the n pole groups to switch the noise reduction device from the current noise reduction mode to the target noise reduction mode.

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

[0015] Fourthly, this disclosure provides a computer program product including computer instructions that, when executed by a processor, implement the steps of the method described in the first aspect.

[0016] In this disclosure, the zeros and poles corresponding to the coefficient function of the filter in the current noise reduction mode and the target noise reduction mode are obtained. Based on this, a zero-point group and a pole-point group are constructed for zero-pole switching. This enables a smooth switching of the filter from the current noise reduction mode to the target noise reduction mode, avoiding time loss caused by disordered switching and effectively shortening the noise reduction mode switching time of the noise reduction device. Furthermore, it supports noise reduction mode switching even when the device is not muted, preventing interruption of music / calls. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a noise reduction mode switching method provided in an embodiment of this application;

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

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

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

[0021] Figure 5 This is a distribution diagram of different zeros of a filter on the imaginary positive half-axis, corresponding to different filter parameters, provided in an embodiment of this application.

[0022] Figure 6 This is a schematic diagram of the noise reduction mode switching process of a filter with and without zero-pole pairing, according to an embodiment of this application.

[0023] Figure 7 This is a schematic diagram of a noise reduction mode switching device provided in an embodiment of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0025] This disclosure provides a method for switching noise reduction modes, such as... Figure 1 As shown, the method includes:

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

[0027] Wherein, 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 in the current noise reduction mode, 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.

[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 of the multiple noise reduction modes;

[0029] The plurality of noise reduction modes includes at least two of the following:

[0030] No noise reduction mode, different levels of noise reduction intensity corresponding to different noise reduction modes, transparency mode - ambient sound, transparency mode - voice, specific environment mode - wind noise, specific environment mode - airport.

[0031] Specifically, when the noise-canceling device is in no noise-canceling mode, it can be understood that the noise-canceling function is turned off. At this time, external sounds and audio played through the noise-canceling device can be heard by the user. This is usually used in quiet environments (such as libraries) or when the user wants to hear the surrounding sounds (such as when the user is crossing the road).

[0032] When the noise cancellation device is in graded noise cancellation mode, it can be understood that the noise cancellation device has enabled the active noise cancellation function and provides multiple levels corresponding to multiple noise cancellation intensities. Users can select different levels (such as strong, medium, and weak) according to the intensity of ambient noise. For example, in a quiet indoor environment, select graded noise cancellation mode - weak level, while in a noisy outdoor environment, select graded noise cancellation mode - strong level. At this time, the audio played by the noise cancellation 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 cancellation device is in pass-through mode - ambient sound, it can be understood that the noise cancellation device will amplify the sound of the surrounding environment, allowing users to clearly hear traffic, conversations or other important sounds. This can help users perceive the surrounding environment and avoid potential dangers when walking or cycling on the street.

[0034] Similarly, when the noise-canceling device is in pass-through mode - voice mode, it can be understood that the noise-canceling device will focus on enhancing human voice, so that users can hear others speaking more easily while listening to music, so that users can communicate with others in social situations or office environments without taking off their headphones.

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

[0036] When the noise-canceling device is in a specific environment mode - airport mode, it can be understood that the noise-canceling device has enabled the adaptive noise cancellation function. The noise-canceling device is mainly used to reduce the interference of background noise (such as the sound of people talking, the sound of airplanes taking off 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 the actual situation. This application does not limit the specific noise reduction mode indicated by the current noise reduction mode and the target noise reduction mode.

[0038] Specifically, by factoring the system function of the filter in the noise reduction device in the current noise reduction mode according to the zeros and poles, we can obtain a number of first zeros and a number of first poles corresponding to the system function of the filter in the current noise reduction mode in the complex plane.

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

[0040] The zeros of the filter parameters of the filter's system function in the complex plane can be understood as the points in the complex plane corresponding to the solutions that make the numerator polynomial of the filter's system function equal to zero.

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

[0042] The noise reduction device can be any electronic device with active noise reduction function, such as active noise-canceling headphones.

[0043] Without loss of generality, when the noise-canceling device is an active noise-canceling headphone, the signal path block diagram of the noise-canceling 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 decimator, an active noise cancellation filter (ANC filter), an interpolator, a Sigma-Delta modulator (SDM), and a digital-to-analog converter (DAC).

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

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

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

[0047] Factoring the system function according to its zeros and poles yields the zeros and poles of the filter in the complex plane. Generally, a second-order filter corresponds to a pair of zeros and a pair of poles in the complex plane. That is, generally speaking, a second-order filter formed by cascading N IIR filters 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-groups and n pole-groups.

[0049] Each zero group includes a first zero and a second zero, with different first zeros located in different zero groups and different second zeros located in different zero groups. Each pole group includes a first pole and a second pole, with different first poles located in different pole groups and different second poles located in different pole groups.

[0050] It should be noted that the above 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 (which has the shortest noise reduction mode switching time) as n zero-point groups and n pole groups. This can shorten the noise reduction mode switching time while avoiding filter instability problems during the noise reduction mode switching process. At the same time, it supports noise reduction mode switching in the non-mute state, which can avoid interrupting music / calls.

[0051] In one example, if the first zero-pole information includes the first zero A_a1, the first zero A_a2, the first pole A_b1, and the first pole A_b2, and the second zero-pole information includes the second zero B_a1, the second zero B_a2, the second pole B_b1, and the second pole B_b2, the zero-point group and pole group are obtained by random combination.

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

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

[0054] or,

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

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

[0057] Pole set [A_b1, B_b1] and pole set [A_b2, B_b2];

[0058] or,

[0059] Pole set [A_b1, B_b2] and pole set [A_b2, B_b1].

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

[0061] In this disclosure, the zeros and poles corresponding to the coefficient function of the filter in the current noise reduction mode and the zeros and poles 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 filter switching disorderly, and effectively shorten the noise reduction mode switching time of the noise reduction device.

[0062] In one embodiment, combining the first zero-pole information and the second zero-pole information to obtain n zero 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. Each candidate combination strategy includes n candidate zero-point groups and n candidate pole-point groups. Each candidate zero-point group includes a first zero and a second zero. Different first zeros are located in different candidate zero-point groups, and different second zeros are located in different candidate zero-point groups. Each candidate pole-point group includes a first pole and a second pole. Different first poles are located in different candidate pole-point groups, and different second poles are located in different candidate pole-point groups. m is the factorial of n.

[0064] In the m candidate combination strategies, the switching parameters corresponding to each candidate combination strategy are calculated, wherein the switching parameters are the sum of multiple zero distances and multiple pole distances in the corresponding candidate combination strategy, the zero distance is the distance between the first zero and the second zero in the corresponding candidate zero 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 with the smallest switching parameter is determined as the target combination strategy, and the candidate zero group and candidate pole group included in the target combination strategy are respectively determined as the zero group and the pole group.

[0066] The switching parameter is used to represent the time taken to switch noise reduction modes according to the corresponding candidate combination strategy. The smaller the switching parameter, the less time is taken to switch noise reduction modes according to the corresponding candidate combination strategy.

[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. Then, the switching parameters corresponding to each candidate combination strategy are calculated, and the candidate combination strategy with the smallest switching parameters is determined as the target combination strategy, that is, the optimal combination strategy. Based on this, n zero groups and n pole groups for zero-pole switching are obtained, which can shorten the time of subsequent zero-pole switching and avoid the risk of filter instability (such as the pole crossing the unit circle during mode switching) introduced by unreasonable candidate combination strategies.

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

[0069] When performing zero-pole switching based on the n zero-point groups and the n pole-point groups, the first zero in each zero-point group is switched to the second zero in that zero-point group, and the first pole in each pole group is switched to the second pole in that 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, thereby switching the noise reduction device from the current noise reduction mode to the target noise reduction mode.

[0070] Further, the zero-pole switching based on the n zero groups and the n pole groups includes:

[0071] Interpolation is performed between the first zero point and the second zero point included in each zero point group to obtain the zero point switching point set corresponding to each zero point group;

[0072] Interpolation is performed between the first pole and the second pole included in each pole group to obtain the pole switching point set corresponding to each pole group;

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

[0074] When switching the first zero point of each zero point group to the second zero point of that zero point group, and when switching the first pole of each pole group to the second pole of that pole group, multiple zero point switching points / pole switching points are obtained through interpolation during the switching process. This allows the switching process from the first zero point to the second zero point within the same zero point group to be divided into multiple stages, and the switching process from the first pole to the second pole within the same pole group to be divided into multiple stages. This makes the zero-pole switching smoother and the changes in the audio played by the noise-canceling device during noise-canceling mode switching more gradual, providing users with a better listening experience.

[0075] For example, for each zero point group, interpolation within the line segment with the first and second zero points included in the zero point group as endpoints can minimize the path from the first zero point included in the zero point group to the second zero point included in the zero point group, and reduce the overall time consumption of noise reduction mode switching to a certain extent.

[0076] Similarly, for each pole group, interpolation within the line segment with the first and second poles included in the pole group as endpoints can minimize the path from the first pole included in the pole group to the second pole included in the pole group.

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

[0078] The zero-point switching step size for each zero-point group is calculated according to preset parameters, wherein the zero-point switching step size 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 to the preset parameters.

[0079] Based on the zero-point switching step size 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 the 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 size.

[0080] The step of interpolating between the first and second poles included in each pole group to obtain the pole switching point set corresponding to each pole group includes:

[0081] The pole switching step size for each pole group is calculated based on the preset parameters, wherein the pole switching step size is the ratio of the distance between the first pole and the second pole of the corresponding pole group in the complex plane to the preset parameters.

[0082] Based on the pole switching step size of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain the 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 size.

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

[0084] In the complex plane, the first zero point included in each zero point group is taken as the starting point, the second zero point included in each zero point group is taken as the ending point, and the set of zero point switching points corresponding to each zero point group is taken as the movement path, and the zero point movement operation corresponding to each zero point group is executed.

[0085] In the complex plane, the first pole included in each pole group is taken as the starting point, the second pole included in each pole group is taken as the ending point, and the set of pole switching points corresponding to each pole group is taken as the movement path, and the pole movement operation corresponding to each pole group is executed.

[0086] Among them, the zero-point movement operation performed for any zero-point group and the pole-point movement operation performed for any pole-point group are synchronous operations.

[0087] By using linear interpolation, the number of switching steps for different zero groups and different pole groups is unified, ensuring the synchronous execution of switching operations for different zero groups and different pole groups.

[0088] The number of switching steps can be understood as the value indicated by the aforementioned preset parameters. Users can make adaptive adjustments to the preset parameters according to their actual needs.

[0089] Without loss of generality, when making step-by-step switching based on the above-mentioned number of switching steps, the interval between each switching step can be set to a predetermined value. This allows for flexible adjustment of the number of switching steps to support different requirements for switching smoothness. For example, setting a larger number of switching steps can provide users with a smoother noise cancellation mode switching experience and reduce the interference of noise cancellation mode switching on the user's normal listening. Setting a smaller number of switching steps can reduce unnecessary operation overhead while ensuring the smoothness of the switching process, and at the same time shorten the overall time of noise cancellation mode switching.

[0090] Taking the example of a noise reduction device where the filter is formed by two second-order filters connected in series, such as... Figure 4 As shown, the current noise reduction mode is set to graded noise reduction mode - high setting, and the target noise reduction mode is transparency mode. The multiple filter parameters of the filter in the current system function of the current noise reduction mode are collectively referred to as A, and the multiple filter 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 described in... Figure 4 This can be viewed as the zeros of A moving to the zeros of B in q steps, and the poles of A moving to the poles of B in q steps, with each step moving 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 parameters, i.e., the number of switching steps.

[0091] The zero-point distribution diagram of A and B on the positive imaginary axis can be shown as follows: Figure 5 As shown, A_z1 and A_z2 represent the two zeros of A on the positive imaginary axis (in... Figure 5 In the diagram, B is represented by a hollow circle, which is also the two first zeros. B_z1 and B_z2 represent the two zeros of B on the positive imaginary axis (in the diagram). Figure 5 The center is represented by a solid circle, that is, two second zero points, by Figure 5 It can be observed that the distance moved from A_z1 to B_z2 is significantly shorter than the distance moved from A_z1 to B_z2, and the distance moved from A_z2 to B_z1 is also shorter than the distance moved from A_z1 to B_z1.

[0092] Therefore, the total path for switching zero points by forming a zero point group from A_z1 and B_z2 and another zero point group from A_z2 and B_z1 is significantly shorter than the total path for switching zero points by forming a zero point group from A_z1 and B_z1 and another zero point group from A_z2 and B_z2.

[0093] In other words, by forming a zero-point group with A_z1 and B_z2, and another zero-point group with A_z2 and B_z1, the movement distance of the zero-point parameters can be minimized during the switching from A to B.

[0094] like Figure 6 As shown, assuming q = 4096, the adjustment step size of each zero group is the ratio of the distance between the two zeros in the zero group to q, and the adjustment step size of each pole group is the ratio of the distance between the two poles in the pole group to q. The adjustment interval for each step is 60us. Using a 1000Hz sine wave as the filter input, observe the output curve (light gray curve) of the filter during the parameter adjustment process. 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 a set parameter threshold.

[0096] Based on the above settings, the noise reduction device can adaptively adjust preset parameters based on the audio quality of the currently transmitted audio, thereby further reducing the interference of noise reduction mode switching on the user's normal listening experience.

[0097] Specifically, before switching noise reduction modes, the noise reduction device monitors the audio quality of the currently transmitted audio. If the audio quality is high (e.g., higher bit rate, higher sampling rate), a first parameter value is assigned to a preset parameter. If the audio quality is average (e.g., lower bit rate, lower sampling rate), a second parameter value is assigned to the preset parameter. The first parameter value is greater than the second parameter value to allow for a larger switching step size for high-quality audio, thereby improving the smoothness of the noise reduction mode switching process and reducing interference with the user's normal listening experience. Conversely, a smaller switching step size is set for low-quality audio, minimizing interference with the user's normal listening experience while minimizing the overall time required for the noise reduction mode switching.

[0098] In one embodiment, the noise reduction device is in an unmute state during the process of switching from the current noise reduction mode to the target noise reduction mode.

[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 unmute state to avoid interrupting the original listening / calling actions when switching noise reduction modes, saving unnecessary time caused by performing mute and unmute operations, and avoiding interference with the user's current listening / calling actions, thus bringing a better user experience.

[0100] See Figure 7 , Figure 7 This disclosure provides a noise reduction mode switching device, such as... 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, where n is an integer greater than 1.

[0102] The information combination module 702 is used to combine the first zero-pole information and the second zero-pole information to obtain n zero-point groups and n pole groups. Each zero-point group includes a first zero and a second zero, with different first zeros located in different zero-point groups and different second zeros located in different zero-point groups. Each pole group includes a first pole and a second pole, with different first poles located in different pole groups and different second poles 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 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 multiple filtering parameters of the filter in the current system function are different from the values ​​of multiple filtering parameters of the filter in the target system function;

[0105] When performing zero-pole switching based on the n zero-point groups and the n pole-point groups, the first zero in each zero-point group is switched to the second zero in that zero-point group, and the first pole in each pole group is switched to the second pole in that 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, thereby switching the noise reduction device 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 is used to interpolate between the first zero point and the second zero point included in each zero-point group to obtain a set of zero-point switching points corresponding to each zero-point group;

[0108] A pole interpolation unit is used to interpolate between the first pole and the second pole included in each pole group to obtain the pole switching point set corresponding to each pole group;

[0109] The switching unit is used to perform zero-pole switching on the n zero groups and the n pole groups respectively, based on the zero-switching point set corresponding to each zero group and the pole-switching point set corresponding to each pole group.

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

[0111] The zero-point switching step size for each zero-point group is calculated according to preset parameters, wherein the zero-point switching step size 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 to the preset parameters.

[0112] Based on the zero-point switching step size 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 the 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 size.

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

[0114] The pole switching step size for each pole group is calculated based on the preset parameters, wherein the pole switching step size is the ratio of the distance between the first pole and the second pole of the corresponding pole group in the complex plane to the preset parameters.

[0115] Based on the pole switching step size of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain the 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 size.

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

[0117] In the complex plane, the first zero point included in each zero point group is taken as the starting point, the second zero point included in each zero point group is taken as the ending point, and the set of zero point switching points corresponding to each zero point group is taken as the movement path, and the zero point movement operation corresponding to each zero point group is executed.

[0118] In the complex plane, the first pole included in each pole group is taken as the starting point, the second pole included in each pole group is taken as the ending point, and the set of pole switching points corresponding to each pole group is taken as the movement path, and the pole movement operation corresponding to each pole group is executed.

[0119] Among them, the zero-point movement operation performed for any zero-point group and the pole-point movement operation performed for 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 plurality of noise reduction modes include at least two of the following:

[0122] No noise reduction mode, different levels of noise reduction intensity corresponding to different noise reduction modes, 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 for:

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

[0125] In the m candidate combination strategies, the switching parameters corresponding to each candidate combination strategy are calculated, wherein the switching parameters are the sum of multiple zero distances and multiple pole distances in the corresponding candidate combination strategy, the zero distance is the distance between the first zero and the second zero in the corresponding candidate zero 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 with the smallest switching parameter is determined as the target combination strategy, and the candidate zero group and candidate pole group included in the target combination strategy are respectively determined as the zero group and the pole 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 a set parameter threshold.

[0128] In one embodiment, the noise reduction device is in an unmute state during the process of switching from the current noise reduction mode to the target noise reduction mode.

[0129] The noise reduction mode switching device 700 provided in this embodiment can realize the various processes in the above-described noise reduction mode switching method embodiments. To avoid repetition, it will not be described again here.

[0130] According to embodiments of this disclosure, this 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 embodiments 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 the implementation of the present disclosure described and / or claimed herein.

[0132] The noise reduction device provided in this embodiment can realize each process in the above-described noise reduction mode switching method embodiment. To avoid repetition, it will not be described again here.

[0133] This application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above-described... Figure 1 The various processes of the method embodiments 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 rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0135] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for switching noise reduction modes, characterized in that, The method includes: 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, wherein 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; The first zero-pole information and the second zero-pole information are combined to obtain n zero-point groups and n pole-point groups. Each zero-point group includes a first zero and a second zero. Different first zeros are located in different zero-point groups, and different second zeros are located in different zero-point groups. Each pole-point group includes a first pole and a second pole. Different first poles are located in different pole-point groups, and different second poles are located in different pole-point groups. Zero-pole switching is performed based on the n zero-point groups and the n pole-point groups to switch the noise reduction device from the current noise reduction mode to the target noise reduction mode; The values ​​of several filter parameters of the filter in the current system function are different from the values ​​of several filter parameters of the filter in the target system function; When performing zero-pole switching based on the n zero-point groups and the n pole-point groups, the first zero in each zero-point group is switched to the second zero in that zero-point group, and the first pole in each pole group is switched to the second pole in that 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, thereby switching the noise reduction device from the current noise reduction mode to the target noise reduction mode.

2. The method according to claim 1, characterized in that, The zero-pole switching based on the n zero-point groups and the n pole-point groups includes: Interpolation is performed between the first zero point and the second zero point included in each zero point group to obtain the zero point switching point set corresponding to each zero point group; Interpolation is performed between the first pole and the second pole included in each pole group to obtain the pole switching point set corresponding to each pole group; Zero-pole switching is performed on the n zero-point groups and the n pole groups respectively, based on the zero-point switching point set corresponding to each zero-point group and the pole switching point set corresponding to each pole group.

3. The method according to claim 2, characterized in that, The step of interpolating between the first and second zero points included in each zero-point group to obtain the zero-point switching point set corresponding to each zero-point group includes: The zero-point switching step size for each zero-point group is calculated according to preset parameters, wherein the zero-point switching step size 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 to the preset parameters. Based on the zero-point switching step size 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 the 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 size. The step of interpolating between the first and second poles included in each pole group to obtain the pole switching point set corresponding to each pole group includes: The pole switching step size for each pole group is calculated based on the preset parameters, wherein the pole switching step size is the ratio of the distance between the first pole and the second pole of the corresponding pole group in the complex plane to the preset parameters. Based on the pole switching step size of each pole group, linear interpolation is performed between the first pole and the second pole included in each pole group to obtain the 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 size.

4. The method according to claim 2, characterized in that, Based on the zero-switching point set corresponding to each zero group and the pole-switching point set corresponding to each pole group, zero-pole switching is performed on the n zero groups and the n pole groups respectively, including: In the complex plane, the first zero point included in each zero point group is taken as the starting point, the second zero point included in each zero point group is taken as the ending point, and the set of zero point switching points corresponding to each zero point group is taken as the movement path, and the zero point movement operation corresponding to each zero point group is executed. In the complex plane, the first pole included in each pole group is taken as the starting point, the second pole included in each pole group is taken as the ending point, and the set of pole switching points corresponding to each pole group is taken as the movement path, and the pole movement operation corresponding to each pole group is executed. Among them, the zero-point movement operation performed for any zero-point group and the pole-point movement operation performed for any pole-point group are synchronous operations.

5. 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 of the multiple noise reduction modes; The plurality of noise reduction modes include at least two of the following: No noise reduction mode, different levels of noise reduction intensity corresponding to different noise reduction modes, transparency mode - ambient sound, transparency mode - voice, specific environment mode - wind noise, specific environment mode - airport.

6. The method according to claim 1, characterized in that, The combination of the first zero-pole information and the second zero-pole information to obtain n zero-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. Each candidate combination strategy includes n candidate zero-point groups and n candidate pole-point groups. Each candidate zero-point group includes a first zero and a second zero. Different first zeros are located in different candidate zero-point groups, and different second zeros are located in different candidate zero-point groups. Each candidate pole-point group includes a first pole and a second pole. Different first poles are located in different candidate pole-point groups, and different second poles are located in different candidate pole-point groups. m is the factorial of n. In the m candidate combination strategies, the switching parameters corresponding to each candidate combination strategy are calculated, wherein the switching parameters are the sum of multiple zero distances and multiple pole distances in the corresponding candidate combination strategy, the zero distance is the distance between the first zero and the second zero in the corresponding candidate zero 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 with the smallest switching parameter is determined as the target combination strategy, and the candidate zero group and candidate pole group included in the target combination strategy are respectively determined as the zero group and the pole group.

7. The method according to claim 3, characterized in that, The value of the preset parameter is positively correlated with the audio quality of the audio currently transmitted by the noise reduction device, and the value of the preset parameter is less than the set parameter threshold.

8. The method according to claim 1, characterized in that, During the process of switching from the current noise reduction mode to the target noise reduction mode, the noise reduction device is in an unmute state.

9. A noise reduction mode switching device, characterized in that, The device includes: The information acquisition module is used to acquire first zero-pole information and second zero-pole information. 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 in the current noise reduction mode. The target system function is used to indicate the system function of the filter in the target noise reduction mode. n is an integer greater than 1. The information combination module is used to combine the first zero-pole information and the second zero-pole information to obtain n zero-point groups and n pole groups. Each zero-point group includes a first zero and a second zero, with different first zeros located in different zero-point groups and different second zeros located in different zero-point groups. Each pole group includes a first pole and a second pole, with different first poles located in different pole groups and different second poles located in different pole groups. The mode switching module is used to perform zero-pole switching based on the n zero-point groups and the n pole groups, so as to switch the noise reduction device from the current noise reduction mode to the target noise reduction mode; Wherein, the values ​​of multiple filtering parameters of the filter in the current system function are different from the values ​​of multiple filtering parameters of the filter in the target system function; When performing zero-pole switching based on the n zero-point groups and the n pole-point groups, the first zero in each zero-point group is switched to the second zero in that zero-point group, and the first pole in each pole group is switched to the second pole in that 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, thereby switching the noise reduction device from the current noise reduction mode to the target noise reduction mode.

10. A noise reduction device, characterized in that, Used to perform the noise reduction mode switching method as described in any one of claims 1-8.

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