A method of signal conditioning and active noise reduction system

Abstract

The application discloses a signal adjusting method and an active noise reduction system. The method first acquires an external environmental noise signal of a device and an internal noise signal. Then, a filter is used to generate an active noise reduction signal corresponding to the external environmental noise signal and the internal noise signal respectively, to analyze the external environmental noise signal and the internal noise signal, and to determine a scene where the device is located. Finally, based on the scene where the device is located, an expander is used to adjust the active noise reduction signal generated by the filter. The application also discloses an active noise reduction system. In the embodiment of the application, the scene where the device is located is determined through analysis of the noise signal, and the expander processes the active noise reduction signal differently according to different scenes, so that the demand for high noise reduction in a noise scene and the demand for improvement of the bottom noise of the device in a quiet scene can be met.

Description

Technical Field

[0001] This application relates to the field of signal processing, and in particular to a method for signal conditioning and an active noise reduction system. Background Technology

[0002] Active noise cancellation cancels out ambient noise by generating sound waves with the same amplitude but opposite phase as the ambient sound, thus creating a relatively quiet listening experience. The principle is to actively emit sound waves with opposite phase through the headphones to cancel out the sound waves (feedforward) or to add a feedback acoustic path to the sound path (feedback) to reduce the noise heard by the ears.

[0003] In existing technologies, in relatively quiet application scenarios, the limited dynamic range of analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) exacerbates the issue of background noise. In such cases, users may experience even more noise when using active noise cancellation. While adjusting the analog gain of ADCs and DACs can extend the dynamic range, automatically adjusting the analog gain introduces instability into the active noise cancellation system. Increasing the gain on the feedback link when the ambient noise is low can lead to self-oscillation, making the system unstable and exposing users to even more noise. Therefore, it cannot simultaneously meet the requirements of high noise reduction in noisy scenarios and low background noise in quiet scenarios. Summary of the Invention

[0004] In view of this, embodiments of this application provide a signal conditioning method and an active noise reduction system, aiming to meet the requirements of high noise reduction in noisy scenarios and low noise floor in quiet scenarios.

[0005] In a first aspect, embodiments of this application provide a signal modulation method, the method comprising:

[0006] Acquire the external environmental noise signal of the device, and acquire the internal noise signal of the device;

[0007] Active noise reduction signals are generated using filters, corresponding to the external environmental noise signal and the internal noise signal, respectively.

[0008] Analyze the external environmental noise signal and the internal noise signal to determine the scene in which the device is located;

[0009] Based on the scenario in which the device is located, the active noise reduction signal generated by the filter is adjusted using an extender.

[0010] Optionally, adjusting the active noise reduction signal generated by the filter using an extender based on the scenario in which the device is located includes:

[0011] In noisy scenarios, the expander is used to keep the magnitude of the active noise reduction signal generated by the filter constant;

[0012] In quiet scenarios, the extender is used to reduce the active noise reduction signal generated by the filter.

[0013] Optionally, the step of analyzing the external environmental noise signal and the internal noise signal, and determining the scene in which the device is located, includes:

[0014] The external environmental noise signal is received using a feedforward analysis filter, and the internal noise signal is received using a feedback analysis filter. If the external environmental noise signal is less than a first threshold value in the corresponding detection frequency band of the feedforward analysis filter, and the internal noise signal is greater than a second threshold value in the corresponding detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a quiet scene.

[0015] If the external environmental noise signal is greater than a first threshold value in the detection frequency band of the feedforward analysis filter, and the internal noise signal is less than a second threshold value in the detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a noisy scene.

[0016] Optionally, adjusting the active noise reduction signal generated by the filter using an extender based on the scenario in which the device is located includes:

[0017] Based on the scenario in which the device is located, the active noise reduction signal generated by the feedforward filter and the feedback filter is adjusted using an extender.

[0018] Optionally, the step of generating active noise reduction signals corresponding to the external environmental noise signal and the internal noise signal respectively using filters includes:

[0019] The feedforward filter is used to perform amplitude and phase tracking on the external environmental noise signal, and a feedforward active noise reduction signal corresponding to the external environmental noise signal is generated.

[0020] The feedback filter is used to perform amplitude and phase tracking on the internal noise signal, and a feedback active noise reduction signal corresponding to the internal noise signal is generated.

[0021] Optionally, after acquiring the internal noise signal of the device, the method further includes:

[0022] The music signal is removed from the internal signal by the music signal compensation branch.

[0023] Optionally, reducing the active noise-reduced signal generated by the filter using the expander includes:

[0024] The expander is used to reduce the active noise reduction signal generated by the filter by a preset ratio.

[0025] Secondly, embodiments of this application provide an active noise reduction system, the system comprising:

[0026] The system comprises a first microphone, a second microphone, a feedforward filter, a feedback filter, a feedforward analysis filter, a feedback analysis filter, and an extender; wherein the outputs of the feedforward filter, the feedback filter, the feedforward analysis filter, and the feedback analysis filter are connected to the input of the extender; the inputs of the feedforward filter and the feedforward analysis filter are both connected to the output of the first microphone; and the inputs of the feedback filter and the feedback analysis filter are both connected to the output of the second microphone.

[0027] The first microphone is used to acquire ambient noise signals from the external environment of the device;

[0028] The second microphone is used to acquire the internal noise signal of the device;

[0029] The feedforward filter is used to generate an active noise reduction signal corresponding to the external environmental noise signal;

[0030] The feedback filter is used to generate an active noise reduction signal corresponding to the internal noise signal of the device.

[0031] The feedforward analysis filter is used to analyze the external environmental noise signal of the device and obtain the analysis results;

[0032] The feedback analysis filter is used to analyze the internal environmental noise of the device and obtain the analysis results;

[0033] The extender is used to determine the scene in which the device is located based on the analysis results of the feedforward analysis filter and the feedback analysis filter, and adjust the active noise reduction signal generated by the feedforward filter and the feedback filter respectively based on the scene.

[0034] Optionally, the system further includes:

[0035] A music signal compensation branch is connected to the output of the second microphone and is used to remove the music signal from the internal signal.

[0036] Optionally, the expander is specifically used for:

[0037] In noisy scenarios, the magnitude of the active noise reduction signal generated by the feedforward filter and the feedback filter remains unchanged;

[0038] In quiet scenarios, the active noise reduction signal generated by the feedforward filter and the feedback filter is reduced.

[0039] Optionally, the feedforward analysis filter and the feedback analysis filter are specifically used for:

[0040] The external environmental noise signal is received using a feedforward analysis filter, and the internal noise signal is received using a feedback analysis filter. If the external environmental noise signal is less than a first threshold value in the corresponding detection frequency band of the feedforward analysis filter, and the internal noise signal is greater than a second threshold value in the corresponding detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a quiet scene.

[0041] If the external environmental noise signal is greater than a first threshold value in the detection frequency band of the feedforward analysis filter, and the internal noise signal is less than a second threshold value in the detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a noisy scene.

[0042] Optionally, the expander is specifically used for:

[0043] Based on the scenario in which the device is located, the active noise reduction signal generated by the feedforward filter and the feedback filter is adjusted using an extender.

[0044] Optionally, the feedforward filter and the feedback filter are specifically used for:

[0045] The feedforward filter is used to perform amplitude and phase tracking on the external environmental noise signal, and a feedforward active noise reduction signal corresponding to the external environmental noise signal is generated.

[0046] The feedback filter is used to perform amplitude and phase tracking on the internal noise signal, and a feedback active noise reduction signal corresponding to the internal noise signal is generated.

[0047] This application provides a signal conditioning method and an active noise reduction system. When executing the method, firstly, the external environmental noise signal and the internal noise signal of the device are acquired. Then, an active noise reduction signal corresponding to the external environmental noise signal and the internal noise signal is generated using a filter. The external environmental noise signal and the internal noise signal are analyzed to determine the scene in which the device is located. Finally, based on the scene in which the device is located, the active noise reduction signal generated by the filter is adjusted using an expander. In this way, by analyzing the scene in which the device is located and adjusting the active noise reduction signal accordingly using an expander, the requirement of achieving high noise reduction in noisy scenes and improving the device's noise floor in quiet scenes can be met. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A flowchart of a signal conditioning method;

[0050] Figure 2 This is a schematic diagram of an active noise reduction system;

[0051] Figure 3 This is a schematic diagram of an active noise cancellation system in a real-world application scenario. Detailed Implementation

[0052] Research on existing technologies reveals that active noise cancellation primarily refers to generating sound waves with the same amplitude but opposite phase as the ambient sound to cancel out external noise and create a relatively quiet listening experience. Current technologies mainly achieve dynamic range expansion by adjusting the analog gain of analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). However, in relatively quiet environments, the limited dynamic range of ADCs and DACs means that increased analog gain during active noise cancellation can lead to self-oscillations, making the noise even louder and failing to meet the user's need to reduce background noise in quiet environments.

[0053] Based on this, this application proposes a signal conditioning method, an active noise reduction system, and a computer storage medium, which can meet the user's noise reduction needs in both noisy and quiet scenarios.

[0054] Figure 1 A flowchart of a signal conditioning method, such as Figure 1 As shown, a signal conditioning method specifically includes:

[0055] S11: Acquire the external environmental noise signal of the device, and acquire the internal noise signal of the device.

[0056] The above mentioned acquiring the external environmental noise signal of the device. This acquisition can be achieved using a first microphone, which collects the external environmental noise and converts it into an analog-to-digital converter (ADC) signal that can be analyzed and processed by a filter. Acquiring the internal noise signal of the device can be achieved using a second microphone. The second microphone collects the internal noise signal of the device. In fact, when collecting sound from inside the device, the collected signal may contain not only noise but also target signals. For example, assuming the device is headphones, the second microphone collects the sound from inside the headphones, capturing both noise and target signals. These target signals can be understood as music signals or other signals that the user needs to hear. These target signals need to be removed by a compensation branch to prevent them from being mistakenly eliminated during noise reduction, thus affecting the user experience. After the target signals are removed, the signal collected by the second microphone is the internal noise of the device. Converting this internal noise into an ADC yields the internal noise signal that can be processed and analyzed by a filter. The compensation branch mentioned above can also be summarized as the target signal compensation branch. If the target signal is a music signal, then the compensation branch can be called a music signal compensation branch; if the target signal is an audio signal, then the compensation branch can be called an audio signal compensation branch. The first microphone and the second microphone were mentioned above. The terms "first" and "second" are not related to the order of the microphones but are used to distinguish them. It is understood that the models and specifications of these two microphones can be the same or different. The specific selection of microphones can be made by those skilled in the art based on the actual situation and application scenario, and will not be specified here.

[0057] S12: Generate active noise reduction signals corresponding to the external environmental noise signal and the internal noise signal respectively using a filter.

[0058] The above mentioned the use of filters to generate active noise reduction signals. The filters referred to here can include feedforward filters and feedback filters.

[0059] In this application embodiment, the device is specifically described using headphones as an example. Active noise cancellation for headphones can be divided into feedforward noise cancellation and feedback noise cancellation, which, when combined, constitute hybrid noise cancellation. Feedforward noise cancellation and feedback noise cancellation each have their own limitations in noise reduction depth and bandwidth, while combining them can maximize the expansion of noise reduction bandwidth and depth. Feedforward noise cancellation is mainly achieved using a feedforward filter, while feedback noise cancellation is mainly achieved using a feedback filter.

[0060] Feedforward filters primarily process external environmental noise signals, while feedback filters primarily process internal noise signals. The specific process of a feedforward filter processing external environmental noise can be understood as the process of the feedforward filter performing amplitude and phase tracking on the external environmental noise. Specifically, this involves using the feedforward filter to track the amplitude and phase of the external environmental noise signal and generating a feedforward active noise reduction signal corresponding to the external environmental noise signal.

[0061] Similarly, the specific processing of internal noise signals by feedback filters can be understood as the process of amplitude and phase tracking of internal noise signals by the feedback filter. Specifically, this involves using the feedback filter to perform amplitude and phase tracking of the internal noise signals and generating a corresponding active noise reduction feedback signal. The specific models and selections of the feedforward and feedback filters mentioned above can be chosen by those skilled in the art based on the actual situation and application scenario, and are not limited here.

[0062] S13: Analyze the external environmental noise signal and the internal noise signal, and determine the scene in which the device is located;

[0063] The above mentioned the analysis of external environmental noise signals and internal noise signals. The specific analysis can be achieved using feedforward analysis filters and feedback analysis filters.

[0064] The feedforward analysis filter is mainly used to analyze external environmental noise signals, while the feedback analysis filter is mainly used to analyze internal noise signals. The specific analysis process involves analyzing the relationship between the noise signal and a threshold value. If the noise signal is greater than the threshold value, it is considered large; if the noise signal is lower than the threshold value, it is considered small. By analyzing both the external environmental noise signal and the internal noise signal, the current environment in which the device operates can be determined.

[0065] For example, when the feedforward analysis filter receives an external ambient noise signal, it shows that the external ambient noise signal is greater than the first threshold value in the corresponding detection frequency band of the feedforward analysis filter; at the same time, when the feedback analysis filter receives an internal noise signal, it shows that the internal ambient noise is less than the second threshold value in the corresponding detection frequency band of the feedback analysis filter. Then, it can be determined that the current scene of the device is a quiet scene.

[0066] When the feedforward analysis filter receives an external environmental noise signal, it shows that the external environmental noise signal is less than the first threshold value in the corresponding detection frequency band of the feedforward analysis filter; at the same time, when the feedback analysis filter receives an internal noise signal, it shows that the internal environmental noise is greater than the second threshold value in the corresponding detection frequency band of the feedback analysis filter. Then, it can be determined that the current scene of the device is a noisy scene.

[0067] The first and second threshold values ​​mentioned above can be the same or different. The specific threshold values ​​can be freely set by those skilled in the art according to the actual situation and application scenario, and are not limited here.

[0068] S14: Based on the scene in which the device is located, adjust the active noise reduction signal generated by the filter using an extender.

[0069] Specifically, in noisy environments, the expander maintains the magnitude of the active noise cancellation (ADC) signal generated by the filter at a constant level; in quiet environments, the expander reduces the magnitude of the ADC signal generated by the filter. The aforementioned filters refer to feedforward and feedback filters. Once the environment in which the device operates is determined, the ADC signals generated by these two filters are adjusted synchronously—either simultaneously reduced or kept constant. The reduction of the ADC signal mentioned above can be achieved by using the expander to reduce the ADC signal by a preset ratio. This preset ratio can be set by those skilled in the art based on the application scenario and actual conditions, and is not limited here.

[0070] In the embodiments proposed in this application, external environmental noise signals and internal noise signals of the device are acquired. Then, filters are used to generate active noise reduction signals corresponding to the external environmental noise signals and the internal noise signals, respectively. The external environmental noise signals and internal noise signals are analyzed to determine the scene in which the device is located. Finally, based on the scene in which the device is located, an expander is used to adjust the active noise reduction signals generated by the filter. This achieves noise reduction for the device in both noisy and quiet scenes by dynamically expanding the dynamic range of noise reduction through the expander.

[0071] Although the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. In certain environments, multitasking and parallel processing may be advantageous.

[0072] In this application embodiment, an active noise reduction system is also provided. Figure 2 This is a schematic diagram of an active noise reduction system, such as... Figure 2 As shown, the active noise cancellation system specifically includes:

[0073] The system comprises a first microphone 100, a second microphone 200, a feedforward filter 300, a feedback filter 400, a feedforward analysis filter 500, a feedback analysis filter 600, and an extender 700; wherein the outputs of the feedforward filter 300, the feedback filter 400, the feedforward analysis filter 500, and the feedback analysis filter 600 are connected to the input of the extender 700; the inputs of the feedforward filter 300 and the feedforward analysis filter 500 are both connected to the output of the first microphone 100; and the inputs of the feedback filter 400 and the feedback analysis filter 600 are both connected to the output of the second microphone 200.

[0074] The first microphone 100 is used to acquire ambient noise signals from the external environment of the device.

[0075] The second microphone 200 is used to acquire the internal noise signal of the device;

[0076] The feedforward filter 300 is used to generate an active noise reduction signal corresponding to the external environmental noise signal;

[0077] The feedback filter 400 is used to generate an active noise reduction signal corresponding to the internal noise signal of the device;

[0078] The feedforward analysis filter 500 is used to analyze the external environmental noise signal of the device and obtain the analysis results;

[0079] The feedback analysis filter 600 is used to analyze the internal environmental noise of the device and obtain the analysis results;

[0080] The extender 700 is used to determine the scene in which the device is located based on the analysis results of the feedforward analysis filter 500 and the feedback analysis filter 600, and adjust the active noise reduction signals generated by the feedforward filter 300 and the feedback filter 400 respectively based on the scene.

[0081] In an optional implementation, the system also includes a music signal compensation branch 800, which is connected to the output of the second microphone 200 and is used to remove the music signal received by the second microphone.

[0082] The function of the music signal compensation branch 800 is to remove the music signal from the signal collected by the second microphone, so as to prevent the music signal from being processed in the same way when noise signal in the signal collected by the second microphone is processed in the subsequent noise reduction process, which would result in the music signal being removed by noise reduction and the user being unable to hear the music signal.

[0083] In an optional implementation, the expander 700 is specifically used to keep the magnitude of the active noise reduction signal generated by the feedforward filter 300 and the feedback filter 400 unchanged in noisy scenarios; and to reduce the active noise reduction signal generated by the feedforward filter 300 and the feedback filter 400 in quiet scenarios.

[0084] Different processing methods for the noise-canceling signal in noisy and quiet scenarios can improve the noise floor in both environments. In noisy scenarios, the magnitude of the active noise-canceling signal remains constant; in quiet scenarios, the magnitude of the active noise-canceling signal is reduced, either by a preset ratio. This achieves a balance between high noise reduction in noisy scenarios and improved device noise floor in quiet scenarios.

[0085] In an optional implementation, a feedforward analysis filter 500 is used to receive external ambient noise signals, and a feedback analysis filter 600 is used to receive internal noise signals. If the external ambient noise signal is less than a first threshold value in the corresponding detection frequency band of the feedforward analysis filter 500, and the internal noise signal is greater than a second threshold value in the corresponding detection frequency band of the feedback analysis filter 600, then the scene in which the device is located is determined to be a quiet scene.

[0086] If the external environmental noise signal is greater than the first threshold value in the detection frequency band of the feedforward analysis filter 500, and the internal noise signal is less than the second threshold value in the detection frequency band of the feedback analysis filter 600, then the scene in which the device is located is determined to be a noisy scene.

[0087] The detection band mentioned above can also be understood as the filter passband, that is, the frequency range of signals that the filter allows to pass through. The main function of feedforward analysis filters and feedback analysis filters is to analyze noise signals to determine whether the current environment of the device is a noisy or quiet scene. The detection band of feedforward analysis filters and feedback analysis filters is the frequency range of signals that each filter allows to pass through.

[0088] In an optional implementation, the feedforward filter 300 is used to perform amplitude and phase tracking on the external environmental noise signal and generate a feedforward active noise reduction signal corresponding to the external environmental noise signal.

[0089] The feedback filter 400 is used to perform amplitude and phase tracking on the internal noise signal and generate a feedback active noise reduction signal corresponding to the internal noise signal.

[0090] The amplitude and phase tracking mentioned above aims to generate an active noise reduction signal corresponding to the noise signal. This active noise reduction signal can then be used to process the noise signal. The feedforward filter mainly processes the external environmental noise signal collected by the first microphone, while the feedback filter mainly processes the internal noise signal collected by the second microphone. Amplitude and phase tracking can be understood as acquiring the amplitude and phase information of the noise signal so that a corresponding noise reduction signal can be generated subsequently.

[0091] In this embodiment, an active noise reduction system is provided, which can improve the background noise of the device in both noisy and quiet scenarios.

[0092] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0093] This application also provides a scenario embodiment. Figure 3 This is a schematic diagram of an active noise cancellation system in a real-world application scenario, such as... Figure 3 As shown, the active noise cancellation system specifically includes:

[0094] A reference microphone, in direct contact with the external environment, is primarily used to collect ambient noise. The input of the reference microphone is used to collect ambient noise. The output of the reference microphone is connected to the input of an analog-to-digital converter (ADC) to convert the collected ambient noise into an ambient noise signal. The output of the ADC is connected to the inputs of a feedforward filter and a feedforward analysis filter, inputting the converted ambient noise signal to these filters. The feedforward filter processes the ambient noise to generate a corresponding active noise-canceling signal, while the feedforward analysis filter analyzes the ambient noise to determine its magnitude. The outputs of the feedforward filter and the feedforward analysis filter are connected to the input of an extender.

[0095] The input of the error microphone is used to acquire signals from within the device. The output of the error microphone is connected to the input of the analog-to-digital converter (ADC). The purpose is to convert the acquired internal sound into an internal audio signal using the ADC. After the internal audio signal is processed by a music compensation branch to remove the music signal, only the internal noise signal remains. This internal noise signal is then input to a feedback filter and a feedback analysis filter. The feedback filter processes the internal noise signal and generates a corresponding active noise reduction signal. The feedback analysis filter analyzes the internal noise signal to determine its magnitude. The outputs of the feedback filter and the feedback analysis filter are connected to the input of the extender.

[0096] The reference microphone mentioned in this embodiment can correspond to the first microphone described above, and the error microphone mentioned in this embodiment can correspond to the second microphone described above.

[0097] The expander's main function is to determine the device's environment based on the signal analysis results from the feedforward and feedback analysis filters. Based on this environment, it processes the active noise-canceling (ADC) signals generated by the feedforward and feedback filters. In quiet environments (low external ambient noise, high internal noise), the ADC signal is reduced; in noisy environments (high external ambient noise, low internal noise), the ADC signal remains unchanged. Since the expander's output is connected to the input of the digital-to-analog converter (DAC), the processed ADC signal is sent as the output signal to the DAC. The DAC then performs analog-to-digital conversion on the output signal, converting it into an audio signal that is sent to the device's speakers along with the music signal, allowing the user to hear the noise-canceling music.

[0098] This application also provides corresponding devices and computer-readable storage media for implementing the solutions provided in this application.

[0099] The device includes a memory and a processor. The memory stores instructions or code, and the processor executes the instructions or code to cause the device to perform a signal modulation method according to any embodiment of this application.

[0100] In practical applications, the computer-readable storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0101] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0102] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0103] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0104] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for signal conditioning, characterized in that, The method includes: Acquire the external environmental noise signal of the device, and acquire the internal noise signal of the device; Active noise reduction signals are generated using filters, corresponding to the external environmental noise signal and the internal noise signal, respectively. Analyze the external environmental noise signal and the internal noise signal to determine the scene in which the device is located; Based on the scenario in which the device is located, the active noise reduction signal generated by the filter is adjusted using an extender; The active noise reduction signal generated by the filter, adjusted using an extender based on the scene in which the device is located, includes: In noisy scenarios, the expander is used to keep the magnitude of the active noise reduction signal generated by the filter constant; In quiet scenes, the expander is used to reduce the active noise reduction signal generated by the filter; The analysis of the external environmental noise signal and the internal noise signal, and the determination of the scene in which the device is located, includes: The external environmental noise signal is received using a feedforward analysis filter, and the internal noise signal is received using a feedback analysis filter. If the external environmental noise signal is less than a first threshold value in the corresponding detection frequency band of the feedforward analysis filter, and the internal noise signal is greater than a second threshold value in the corresponding detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a quiet scene. If the external environmental noise signal is greater than a first threshold value in the detection frequency band of the feedforward analysis filter, and the internal noise signal is less than a second threshold value in the detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a noisy scene.

2. The method according to claim 1, characterized in that, The active noise reduction signal generated by the filter, adjusted using an extender based on the scene in which the device is located, includes: Based on the scenario in which the device is located, the active noise reduction signal generated by the feedforward filter and the feedback filter is adjusted using an extender.

3. The method according to claim 2, characterized in that, The step of generating active noise reduction signals corresponding to the external environmental noise signal and the internal noise signal using filters includes: The feedforward filter is used to perform amplitude and phase tracking on the external environmental noise signal, and a feedforward active noise reduction signal corresponding to the external environmental noise is generated. The feedback filter is used to perform amplitude and phase tracking on the internal noise signal, and a feedback active noise reduction signal corresponding to the internal noise signal is generated.

4. The method according to claim 1, characterized in that, After acquiring the internal noise signal of the device, the method further includes: The music signal is removed from the internal signal by the music signal compensation branch.

5. The method according to claim 1, characterized in that, The reduction of the active noise-canceling signal generated by the filter using the expander includes: The expander is used to reduce the active noise reduction signal generated by the filter by a preset ratio.

6. An active noise cancellation system, characterized in that, The system includes: a first microphone, a second microphone, a feedforward filter, a feedback filter, a feedforward analysis filter, a feedback analysis filter, and an extender; wherein the outputs of the feedforward filter, the feedback filter, the feedforward analysis filter, and the feedback analysis filter are connected to the input of the extender; the inputs of the feedforward filter and the feedforward analysis filter are both connected to the output of the first microphone; and the inputs of the feedback filter and the feedback analysis filter are both connected to the output of the second microphone. The first microphone is used to acquire ambient noise signals from the external environment of the device; The second microphone is used to acquire the internal noise signal of the device; The feedforward filter is used to generate an active noise reduction signal corresponding to the external environmental noise signal; The feedback filter is used to generate an active noise reduction signal corresponding to the internal noise signal of the device. The feedforward analysis filter is used to analyze the external environmental noise signal of the device and obtain the analysis results; The feedback analysis filter is used to analyze the internal environmental noise of the device and obtain the analysis results; The extender is used to determine the scene in which the device is located based on the analysis results of the feedforward analysis filter and the feedback analysis filter, and adjust the active noise reduction signal generated by the feedforward filter and the feedback filter respectively based on the scene. The expander is specifically used for: In noisy scenarios, the magnitude of the active noise reduction signal generated by the feedforward filter and the feedback filter remains unchanged; In quiet scenarios, the active noise reduction signal generated by the feedforward filter and the feedback filter is reduced; The feedforward analysis filter and the feedback analysis filter are specifically used for: The external environmental noise signal is received using a feedforward analysis filter, and the internal noise signal is received using a feedback analysis filter. If the external environmental noise signal is less than a first threshold value in the corresponding detection frequency band of the feedforward analysis filter, and the internal noise signal is greater than a second threshold value in the corresponding detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a quiet scene. If the external environmental noise signal is greater than a first threshold value in the detection frequency band of the feedforward analysis filter, and the internal noise signal is less than a second threshold value in the detection frequency band of the feedback analysis filter, then the scene in which the device is located is determined to be a noisy scene.

7. The system according to claim 6, characterized in that, The system also includes: A music signal compensation branch is connected to the output of the second microphone and is used to remove the music signal from the internal signal.

Images