Active noise cancellation audio device, active noise cancellation method, and storage medium

Abstract

The embodiments of the present specification relate to an active noise cancellation audio device, an active noise cancellation method, and a storage medium. The device includes a speaker, a microphone, an analog filter, and a processing circuit. The speaker generates a noise cancellation sound, and the microphone collects environmental noise and the noise cancellation sound to generate a first analog signal. The analog filter gives a gain to the first analog signal and generates a second analog signal that drives the speaker to generate the noise cancellation sound. The processing circuit sends a control command to the analog filter based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter. The present specification uses an analog filter to adjust the amplitude and phase of the analog signal, thereby generating the noise cancellation sound, and can reduce the delay caused by the signal conversion stage and digital filter processing, so that the audio device can make a timely noise cancellation response and improve the noise cancellation effect.

Description

[Technical Field]

[0001] The present specification relates to the field of audio noise cancellation, and in particular to an active noise cancellation audio device, an active noise cancellation method and a storage medium. [Background technology]

[0002] In audio devices, active noise cancellation technology is often used to reduce environmental noise. For example, the audio device collects and analyzes external environmental noise using a microphone, and generates a noise-canceling sound that is opposite in phase to the external environmental noise. Therefore, when the sound emitted from the audio device reaches a human ear, the external environmental noise and the noise-canceling sound cancel each other out, thereby achieving the effect of noise removal.

[0003] Audio devices typically use digital filter banks to adjust the gain and phase of signals, but digital filter banks introduce a large delay when processing signals, making it impossible to process external environmental noise in a timely manner, resulting in a slow noise cancellation response and affecting the noise cancellation effect of the audio device. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, there is a need to provide an active noise cancellation audio device that is capable of fast response. [Means for solving the problem]

[0005] One embodiment of the present disclosure provides an active noise-canceling audio device. The device includes a speaker, a microphone, an analog filter, and a processing circuit. The speaker generates a noise-canceling audio signal, and the microphone collects environmental noise and the noise-canceling audio signal to generate a first analog signal. The analog filter applies gain to the first analog signal and generates a second analog signal that drives the speaker to generate the noise-canceling audio. The processing circuit sends a control command to the analog filter based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter.

[0006] The embodiments of the present specification use an analog filter to adjust the amplitude and phase of an analog signal, thereby generating noise-canceling audio, and can reduce the delay caused by the signal conversion (e.g., digital-to-analog conversion) stage and digital filtering, thereby enabling the audio device to provide a timely noise cancellation response and improve the noise cancellation effect.

[0007] In addition, the active noise cancellation audio device according to the embodiments of the present specification further includes a processing circuit, which can adjust the gain and phase shift of the analog filter based on the environmental noise and the analog signal corresponding to the noise cancellation sound, thereby achieving an optimal response of the analog filter to the environmental noise and further improving the noise cancellation effect.

[0008] In some embodiments, adjusting the gain and phase shift of the analog filter by the processing circuitry includes controlling the analog filter to dynamically adjust its gain in response to changes in the amplitude of the first analog signal over a specific time range.

[0009] In some preferred embodiments, the processing circuit includes a first analog-to-digital converter and a second analog-to-digital converter. The first analog-to-digital converter samples the first analog signal to generate a first digital signal, and the second analog-to-digital converter samples the second analog signal to generate a second digital signal. Sending a control command to the analog filter by the processing circuit includes sending a control command to the analog filter by the processing circuit based on the first digital signal and the second digital signal.

[0010] In some embodiments, the analog filter includes a switch gating circuit and a response regulator, and the switch gating circuit adjusts a resistance or capacitance value of the response regulator based on a control command to change the amplitude frequency response and the phase frequency response of the analog filter.

[0011] In some embodiments, the response regulator includes one or more phase modulation units, each phase modulation unit including at least one variable resistor or at least one variable capacitor, and the switch gating circuit adjusting the resistance or capacitance of the response regulator based on the control command includes the switch gating circuit adjusting the resistance of the variable resistor or the capacitance of the variable capacitor based on the control command.

[0012] In some preferred embodiments, the active noise cancellation audio device further includes a first analog summer, a first analog-to-digital converter, and a third analog-to-digital converter. The first analog summer generates a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal, where the second-order response is a response from the speaker to the microphone. The first analog-to-digital converter samples the first analog signal to generate a first digital signal, and the third analog-to-digital converter samples the third analog signal to generate a third digital signal. Sending a control command to the analog filter by the processing circuit includes sending a control command to the analog filter by the processing circuit based on the first digital signal and the third digital signal.

[0013] In some embodiments, the active noise cancellation audio device further includes a fixing structure that fixes the speaker and the microphone to positions near the user's ears and that do not block the user's ear canals.

[0014] In some preferred embodiments, the active noise cancellation audio device further includes a first analog summer, a third analog-to-digital converter, and a fourth analog-to-digital converter. The first analog summer generates a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal, where the second-order response is a response from the speaker to the microphone. The third analog-to-digital converter samples the third analog signal to generate a third digital signal, and the fourth analog-to-digital converter samples the second analog signal to which the second-order response has been added to generate a fourth digital signal. Sending a control command to the analog filter by the processing circuit includes the processing circuit determining a fifth digital signal based on the third digital signal and a transfer function between the user's ear canal and the microphone, and sending a control command to the analog filter based on the fourth digital signal and the fifth digital signal.

[0015] In some embodiments, the transfer function between the user's ear canal and the microphone is obtained by experimental testing or based on a statistical model or a neural network model.

[0016] In some embodiments, the processing circuitry periodically sends control commands to the analog filter.

[0017] An embodiment of the present specification provides an active noise cancellation method, which includes: generating a noise-canceling sound, collecting environmental noise and the noise-canceling sound to generate a first analog signal, applying gain to the first analog signal using an analog filter to generate a second analog signal that generates the noise-canceling sound, and sending a control command based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter.

[0018] In some embodiments, adjusting the gain and phase shift of the analog filter comprises controlling the analog filter to dynamically adjust its gain in response to changes in the amplitude of the first analog signal over a specific time range.

[0019] In some embodiments, the method further includes sampling the first analog signal to generate a first digital signal, sampling the second analog signal to generate a second digital signal, and transmitting a control command, the control command including transmitting the control command based on the first digital signal and the second digital signal.

[0020] In some embodiments, the method further includes adjusting a resistance or capacitance value of a response regulator in the analog filter based on the control command to change the amplitude frequency response and the phase frequency response of the analog filter.

[0021] In some embodiments, the response regulator includes one or more phase modulation units, each phase modulation unit including at least one variable resistor or at least one variable capacitor, and adjusting the resistance or capacitance of the response regulator in the analog filter based on the control command includes adjusting the resistance of the variable resistor or the capacitance of the variable capacitor based on the control command.

[0022] In some embodiments, the method further includes generating a third analog signal based on the first analog signal, the second analog signal, and a second order response corresponding to the second analog signal, where the second order response is a response from a speaker to a microphone; sampling the first analog signal to generate a first digital signal; sampling the third analog signal to generate a third digital signal; and transmitting a control command, where the control command includes transmitting the control command based on the first digital signal and the third digital signal.

[0023] In some embodiments, the method further includes generating a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal, where the second-order response is a response from a speaker to a microphone; sampling the third analog signal to generate a third digital signal; sampling the second analog signal with the added second-order response to generate a fourth digital signal; and transmitting a control command, the control command including determining a fifth digital signal based on the third digital signal and a transfer function between the user's ear canal and a microphone; and transmitting the control command based on the fourth digital signal and the fifth digital signal.

[0024] In some embodiments, the transfer function between the user's ear canal and the microphone is obtained by experimental testing or based on a statistical model or a neural network model.

[0025] In some embodiments, the method further comprises periodically transmitting the control command.

[0026] One embodiment of the present specification provides a computer-readable storage medium storing computer instructions, wherein when a computer reads the computer instructions in the storage medium, the computer executes a method including the steps of generating a noise-canceled audio, collecting environmental noise and the noise-canceled audio to generate a first analog signal, applying gain to the first analog signal using an analog filter to generate a second analog signal that generates the noise-canceled audio, and transmitting control instructions based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter.

[0027] The present specification will be further illustrated by exemplary embodiments, which are not limiting and will be described in detail with reference to the drawings, in which like reference numerals represent like structures. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a structural block diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. [Figure 2] 1 is a schematic diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. [Figure 3A] FIG. 2 is a schematic diagram of a phase modulation unit according to some embodiments of the present disclosure. [Figure 3B] FIG. 2 is a schematic diagram of a phase modulation unit according to some embodiments of the present disclosure. [Figure 4]1 is a schematic diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. [Figure 5] 1 is a schematic diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. [Figure 6] 1 is a schematic diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. [Figure 7] 1 is a flowchart of an active noise cancellation method according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029] In order to more clearly describe the technical means of the embodiments of the present specification, the drawings necessary for describing the embodiments will be briefly described below. Obviously, the drawings described below are only a part of examples or embodiments of the present specification, and those skilled in the art can apply the present specification to other similar scenarios based on these drawings without any creative effort. Unless otherwise clear from the context or specified, the same symbols in the drawings represent the same structures or operations.

[0030] It will be understood that the terms "system," "device," "unit," and / or "module" used herein are ways of distinguishing between various components, elements, members, parts, or assemblies at different levels, however, other terms may be used in place of the above terms if they achieve the same purpose.

[0031] As used herein and in the claims, unless the context clearly dictates otherwise, terms such as "a," "one," "one kind," and / or "the" do not specifically refer to the singular but may include the plural. In general, the terms "comprise" and "containing" merely indicate the inclusion of explicitly identified steps and elements, and these steps and elements are not an exclusive listing, and a method or apparatus may include other steps or elements.

[0032] Flowcharts are used herein to describe operations performed by systems according to embodiments of the present invention. It will be understood that the preceding and following operations are not necessarily performed in exact order. Instead, steps may be processed in reverse order or simultaneously. Other operations may be added to these processes, or one or more operations may be removed from these processes.

[0033] An active noise cancellation audio device according to one or more embodiments of the present specification can be applied to various situations where it is necessary to provide noise-canceled audio in response to environmental noise and avoid interference from environmental noise. For example, the active noise cancellation audio device can provide noise-canceled audio to an audio output device (e.g., audio, earphones, etc.) to improve the quality of audio output, and can provide noise-canceled audio to an audio input device (e.g., pickup, microphone, etc.) to improve the quality of audio collection. In some embodiments, the active noise cancellation audio device can adjust the volume of the output noise-canceled audio in real time in response to the volume of the environmental noise, thereby facilitating an optimal response to the environmental noise and improving the noise cancellation effect.

[0034] In some embodiments, the active noise cancellation audio device may be a feedback active noise cancellation audio device or a feedforward active noise cancellation audio device. In a feedforward active noise cancellation audio device, the microphone mainly receives environmental noise, and a speaker generates a corresponding noise cancellation sound to perform noise cancellation. In a feedback active noise cancellation audio device, the microphone can simultaneously collect environmental noise and the noise cancellation sound generated by the speaker, and a processing circuit generates a feedback signal to drive the speaker to adjust the noise cancellation sound based on the superposition effect of the environmental noise and the noise cancellation sound, thereby achieving a noise cancellation effect. In some embodiments, the active noise cancellation audio device may use other noise cancellation methods, such as feedforward and feedback combined active noise cancellation.

[0035] Currently, active noise cancellation audio devices may include a digital filter bank, an analog-to-digital converter, and a digital-to-analog converter. The analog-to-digital converter converts audio received by a microphone (environmental noise, or audio in which environmental noise and noise-canceling audio are superimposed) into a digital signal. The digital filter bank processes the digital signal to generate a corresponding noise-canceling digital signal. The digital-to-analog converter then converts the noise-canceling digital signal into an analog signal and outputs it through a speaker to cancel out the environmental noise. However, using a digital filter bank for signal processing generates a large delay, preventing the active noise cancellation audio device from processing external environmental noise in a timely manner and resulting in a slow noise cancellation response, which affects the real-time noise cancellation effect of the audio device.

[0036] The active noise cancellation audio device according to the embodiments of the present specification can reduce delays due to the signal conversion (e.g., digital-to-analog conversion) stage and digital filter processing by directly processing (e.g., gain or phase shift) the analog signal corresponding to the noise cancellation audio using an analog filter, thereby enabling the audio device to perform noise cancellation processing in a timely manner and improve the noise cancellation effect.

[0037] In addition, the active noise cancellation audio device according to the embodiments of the present specification further includes a processing circuit, which can adjust the gain and phase shift of the analog filter based on the environmental noise and the analog signal corresponding to the noise cancellation sound, thereby achieving an optimal response of the analog filter to the environmental noise and further improving the noise cancellation effect.

[0038] 1 is a structural block diagram of an active noise cancellation audio device according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 1, the active noise cancellation audio device 100 may include a speaker 110, a microphone 120, an analog filter 130, and a processing circuit 140.

[0039] The speaker 110 is a transducer that converts electrical signals into audio signals. In some embodiments, the active noise canceling audio device 100 is an open-type earphone, and the speaker 110 may be located near the user's ear but not occluding the user's ear. For example, the support structure of the open-type earphone may suspend or clamp the speaker (or a housing that accommodates the speaker) around the user's pinna (e.g., in front of the tragus) or within the contour of the pinna (e.g., near the triangular fossa). In some embodiments, the active noise canceling audio device 100 is a closed-type earphone (e.g., an in-ear earphone or a headphone), and the support structure of the closed-type earphone may position the speaker 110 within the user's ear canal or within a closed space formed by the housing structure surrounding the user's ear. In some embodiments, the support structure may be a fixing member such as an ear-hanging bracket or a head-hanging stent. Illustratively, the active noise canceling audio device 100 may be a loudspeaker earphone, a speaker, a bone conduction earphone, an air conduction earphone, an AR device, a VR device, a head-mounted audio device, an in-car audio device, a hearing aid, or the like, or alternatively, the active noise canceling audio device 100 may be part of an in-car audio system or an in-cabin audio system, providing active noise cancellation for a specific location in a space.

[0040] In some embodiments, the active noise cancellation audio device 100 may be replaced by an active noise cancellation system. The active noise cancellation system may include one or more speakers, microphones, analog filters, and processing circuits, thereby achieving the same functions as the speaker 110, microphone 120, analog filter 130, and processing circuit 140 in the active noise cancellation audio device 100. Of course, one or more of the speakers, microphones, analog filters, and processing circuits in the active noise cancellation system may be integrated into the same device to perform active noise cancellation for a specific location in space, or may exist as separate devices. For example, the active noise cancellation system may include an in-vehicle noise cancellation system, in which the speakers and microphones are independently installed in different devices, and the analog filters and processing circuits are integrated into the same processing module.

[0041] In some embodiments, the speaker 110 may output noise-canceling audio having an opposite phase to that of the environmental noise so that the noise-canceling audio can cancel out the environmental noise. Furthermore, the phase difference between the noise-canceling audio and the environmental noise in the user's ear canal may be 180 degrees. In some embodiments, the speaker 110 may output other audio, such as a reminder audio, audio played according to the user's needs, etc.

[0042] The microphone 120 is a transducer that converts audio signals into electrical signals. In some embodiments, the microphone 120 simultaneously collects environmental noise and the noise-canceled audio, transmits the collected audio to the analog filter 130 or the processing circuit 140 for processing, and feeds back the magnitude and phase of the noise-canceled audio to minimize the audio collected by the microphone 120. In this case, the microphone may be referred to as a feedback microphone. The feedback microphone may be located close to the user's ear canal so that the received audio resembles the audio actually received by the user's ear as closely as possible. In some embodiments, the microphone 120 mainly collects environmental noise and collects as little of the noise-canceled audio generated by the speaker 110 as possible. In this case, the microphone may be referred to as a feedforward microphone. To reduce the influence of the speaker 110 on the feedforward microphone, a physical structure that blocks audio transmission may be located between the feedforward microphone and the speaker 110. Alternatively, the feedforward microphone may be located away from the speaker 110 and near the acoustic zero of the speaker 110.

[0043] In some embodiments, if the microphone is a feedback microphone, it may simultaneously collect the environmental noise and the noise-canceling audio and generate a first analog signal corresponding to the environmental noise and the noise-canceling audio. The amplitude of the first analog signal may reflect the degree to which the environmental noise and the noise-canceling audio cancel each other out. To achieve an ideal noise-canceling effect, the amplitude of the first analog signal should be as small as possible, even down to zero.

[0044] In addition, compared to closed-type or semi-open-type audio devices, in open-type audio devices, the microphone is not placed in the user's ear canal, so the sound received by the user's ear canal and the sound received by the microphone do not match. In some embodiments, a transfer function between the user's ear canal and the microphone may be established, which indicates the correspondence between the sound signal received by the user's ear canal and the sound signal received by the microphone. For specific implementations of open-type audio devices, please refer to the relevant content in Figure 6 below, and therefore, further description will be omitted here.

[0045] To better explain the relationship between the speaker 110 and the microphone 120, FIG. 2 illustrates a specific implementation of the speaker and microphone in an exemplary manner.

[0046] FIG. 2 is a schematic diagram of an active noise cancellation audio device according to some embodiments of the present disclosure.

[0047] 2, y(t) represents an analog signal corresponding to the noise-canceled voice received by the speaker 110, also referred to as a second analog signal, based on which the speaker 110 can generate the noise-canceled voice, p(t) represents an analog signal corresponding to the environmental noise received by the microphone 120, and e(t) is a first analog signal generated by the microphone 120 based on the environmental noise and the noise-canceled voice simultaneously received. Thus, the relationship between the above three types of signals can be expressed as follows:

[0048] e(t)=p(t)+y(t) (1)

[0049] In some embodiments, in order to cancel out the generated noise-canceled voice from the environmental noise, the first analog signal e(t) may be subjected to certain processing (e.g., processing such as phase shifting by a phase shifter and amplification by an amplifier) ​​to generate a second analog signal y(t). Ideally, the second analog signal y(t) and the analog signal p(t) corresponding to the environmental noise cancel each other out, thereby reducing the amplitude of the first analog signal e(t) to zero. Note that the description of the processing of the first analog signal e(t) here is for illustrative purposes only and is not intended to limit corresponding improvements that would be made by those skilled in the art after understanding the principles. For example, the first analog signal e(t) may be phase-shifted or amplified by different electronic devices, such as an amplifier and a phase shifter, respectively, or the first analog signal e(t) may be phase-shifted and amplified simultaneously by the same electronic device (e.g., an analog filter).

[0050] The analog filter 130 is a circuit device that filters an analog signal or a continuous-time signal. In some embodiments, the analog filter 130 may perform signal processing on the analog signal. Illustratively, the analog filter 130 may simultaneously perform phase shifting and amplification on the analog signal to adjust the phase and amplitude of the analog signal.

[0051] In some embodiments, the analog filter 130 may apply a gain to the first analog signal to generate a second analog signal that drives the speaker 110 to generate noise-canceled audio. For example, as shown in FIG. 2 above, the gain of the analog filter 130 may be expressed as h(t) in the time domain and as H(s) in the frequency domain, and the analog filter 130 may apply a gain h(t) to the first analog signal e(t) to generate a second analog signal y(t). Thus, the relationship between the above three types of signals can be expressed in the time domain as follows:

[0052] y(t)=e(t)*h(t) (2)

[0053] where * is a convolution operation. In some embodiments, based on the above equations (1) and (2), the corresponding relationships between the first analog signal e(t) and the gain h(t) of the analog filter 130 in the time domain and the frequency domain can be expressed as follows:

[0054]

number

[0055] where E(s) is the frequency domain representation of the first analog signal, P(s) is the frequency domain representation of the analog signal corresponding to the environmental noise, and H(S) is the frequency domain gain of the analog filter 130.

[0056] As shown in equation (3), the larger the gain H(S) of the analog filter 130, the closer the value of the first analog signal E(s) is to 0, and the closer it is to an ideal state of active noise cancellation (i.e., the second analog signal y(t) and the analog signal p(t) corresponding to environmental noise can cancel each other out). Thus, the active noise cancellation audio device 100 may be provided with an analog filter 130 having a large gain H(S) to improve the noise cancellation effect.

[0057] In some embodiments, the analog filter 130 may adjust its gain and phase shift based on a control command from the processing circuit 140 to prevent the noise cancellation effect of the active noise cancellation audio device 100 from becoming unstable due to a gain that is too large or too small. For example, when the active noise cancellation audio device 100 is in an initial state, the value of the first analog signal is mainly derived from the contribution of environmental noise (i.e., the second analog signal in the initial state is small or almost zero). In this case, the analog filter 130 may be set to have a small gain to prevent the first analog signal from being over-amplified and generating a second analog signal with an excessively large amplitude the next time, causing the speaker to emit an excessively loud noise cancellation sound and damaging the device. Within a specific time range, the processing circuit 140 can control the analog filter 130 to dynamically adjust its gain as the amplitude of the first analog signal changes. For example, within a certain period of time from when the active noise cancellation audio device 100 is in the initial state, the gain of the analog filter 130 can be continuously increased as the amplitude of the first analog signal decreases, thereby preventing the second analog signal from being unable to cancel out the analog signal corresponding to the environmental noise due to the gain being too small. The specific adjustment method of the analog filter 130 can be referenced in the relevant content of the processing circuit below, and therefore will not be described here. In some embodiments, if the environmental noise fluctuates during the operation of the active noise cancellation audio device 100, the analog filter 130 can dynamically adjust the gain of the analog filter 130 under the control of the processing circuit 140 to adapt to the change in the environmental noise. For example, if the environmental noise increases at a certain time, the amplitude of the first analog signal increases accordingly, and the processing circuit 140 can control the analog filter 130 to reduce its gain, thereby preventing the first analog signal from being over-amplified and damaging the speaker.

[0058] In some embodiments, the analog filter 130 may include a switch gate circuit and a response regulator, and the switch gate circuit adjusts the resistance or capacitance of the response regulator based on a control command to change the amplitude frequency response and phase frequency response of the analog filter 130, thereby realizing phase shifting and / or amplification of the first analog signal.

[0059] In some embodiments, the switch gate circuit may adjust the resistance or capacitance of the response regulator using an analog switch. Furthermore, different channels of the response regulator have different resistance or capacitance values, and the analog switch can change the channel of the response regulator by changing its position to adjust the resistance or capacitance of the response regulator. For example, the response regulator includes a potentiometer, and the resistance of the response regulator can be changed by changing the position of the analog switch to change the channel connected to the potentiometer circuit.

[0060] In some embodiments, the switch gating circuit may adjust the state of the switch itself based on the control command. For example, if the control command is a pulse signal, the switch gating circuit may adjust the position of the analog switch based on the frequency of the pulse signal. In some embodiments, the switch gating circuit may periodically receive the control command from the processing circuit 140. For details on the specific implementation of the control command, please refer to the related description of the processing circuit below, and therefore will not be described here.

[0061] The response regulator may be a circuit device that processes a signal. Exemplarily, the response regulator may perform signal processing (e.g., phase shifting and amplification) on an input first analog signal to obtain a second analog signal. In some embodiments, the resistance or capacitance of the response regulator may affect the amplitude and phase frequency responses of the analog filter 130, thereby affecting the effect of the signal processing. Exemplarily, if the first analog signal does not change and the resistance or capacitance of the response regulator changes, the amplitude and phase frequency responses of the analog filter 130 will change, thereby changing the amplitude and phase of the second analog signal output by the analog filter 130. A specific implementation of the response regulator will be described in detail below, taking a phase modulation unit as an example.

[0062] In some embodiments, the response regulator may include one or more phase modulation units, each of which may include at least one variable resistor or at least one variable capacitor, and the switch gate circuit may correspondingly adjust the resistance value of the variable resistor or the capacitance value of the variable capacitor based on the control command.

[0063] The phase modulation unit may be a circuit set of multiple devices with adjustable parameters. In some embodiments, the response regulator may change the resistance value or capacitance value of the response regulator by changing the resistance value of a variable resistor or the capacitance value of a variable capacitor in the phase modulation unit. The variable resistor may be a slide resistor, a potentiometer, a resistor, etc., and the specific type of the variable resistor may be selected according to the type of switch gate circuit. The variable capacitor may be a patch variable capacitor, a plug-in variable capacitor, etc., and the specific type of the variable capacitor may be selected according to the type of switch gate circuit. Figures 3A and 3B illustrate specific implementations of the phase modulation unit in an exemplary manner.

[0064] FIG. 3A is a schematic diagram of a phase modulation unit according to some embodiments of the present disclosure.

[0065] 3A, the phase modulation unit 310 may include a capacitor C1, a resistor R1, and a voltage follower Q1. The capacitor C1 and the resistor R1 are connected in series, one end of the capacitor C1 is grounded, the connection point between the capacitor C1 and the resistor R1 is connected to the positive-phase input terminal of the voltage follower Q1, and the negative-phase input terminal of the voltage follower Q1 is connected to the output terminal. The phase modulation unit 310 is configured to modulate a signal U i1 Signal processing is performed on the signal U o1 In the embodiment of the present application, the voltage follower Q1 can prevent the phase modulation unit 310 from being affected by the subsequent circuit, and can maintain stable operation of the phase modulation unit 310.

[0066] FIG. 3B is a schematic diagram of a phase modulation unit according to some embodiments of the present disclosure.

[0067] 3B, the multiple phase modulation units 320 are connected in series, and each phase modulation unit 320 may include a capacitor (e.g., capacitor C2) and a resistor (e.g., resistor R2) connected in series, with the resistor (e.g., resistor R2) in the phase modulation unit 320 being connected in series with the resistors (e.g., resistors R3 and R4) of the other phase modulation units 320, and the capacitor (e.g., capacitor C2) in the phase modulation unit 320 being connected in parallel with the capacitors (e.g., capacitors C3 and C4) of the other phase modulation units 320. i2 Signal processing is performed on the signal U o2 can be obtained.

[0068] In some embodiments, the range of the phase frequency response of the response regulator may be adjusted by adjusting the number of series-connected phase modulation units 320. Illustratively, the greater the number of series-connected phase modulation units 320, the greater the range of the phase frequency response of the response regulator.

[0069] As a result, the transfer function of the phase modulation unit (for example, the above-mentioned phase modulation unit 310 and phase modulation unit 320) can be expressed as follows:

[0070]

number

[0071] Here, R is the resistance value of the resistor in the phase modulation unit, and C is the capacitance value of the capacitor in the phase modulation unit. Correspondingly, the phase frequency response of one phase modulation unit may be expressed as -arctan(wRC), and the range of the phase frequency response may be [-90°, 0°].

[0072] In some embodiments, the capacitors C1 to C4 may be variable capacitors, or the resistors R1 to R4 may be variable resistors. Note that FIGS. 3A and 3B only show that the resistors R1 to R4 are variable resistors. By adjusting the capacitance value of the variable capacitors (e.g., capacitors C1 to C4) or the resistance value of the variable resistors (e.g., resistors R1 to R4), the phase frequency response of the phase modulation unit can be changed within [-90°, 0°]. Correspondingly, the switch gate circuit can adjust the path connected to the circuit using an analog switch corresponding to the variable device based on a control command, thereby achieving adjustment of the capacitance value of the capacitors C1 to C4 or the resistance value of the resistors R1 to R4.

[0073] In the embodiment of the present application, the cooperation of the switch gate circuit and the response regulator can adjust the amplitude frequency response and phase frequency response of the analog filter 130, preventing the analog filter 130 from providing too much or too little gain at a particular time, and achieving an optimal response of the analog filter 130 to environmental noise, thereby improving the noise cancellation effect of the active noise cancellation audio device 100.

[0074] Processing circuitry 140 may be a circuit unit having a data processing control function. In some embodiments, processing circuitry 140 may include a circuit module such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a complex programmable logic device (CPLD), a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), or a graphics processing unit (GPU).

[0075] In some embodiments, in a specific time range, as the amplitude of the first analog signal changes, processing circuit 140 may control analog filter 130 to dynamically adjust its gain. Illustratively, the specific time range may be a time period after active noise cancellation audio device 100 starts operating, and as active noise cancellation audio device 100 starts operating, processing circuit 140 sends a control command to gradually increase the gain of analog filter 130 as the amplitude of the first analog signal decreases, thereby maintaining the amplitude of the second analog signal close to the amplitude of the analog signal corresponding to the environmental noise and improving the noise cancellation effect of the device.

[0076] It should be noted that when the active noise cancellation audio device 100 is in the initial state (i.e., the state when the active noise cancellation audio device 100 starts to operate), most of the external environmental noise has not been cancelled out, causing the amplitude of the first analog signal to be large. In this case, the processing circuit 140 sends a control command to reduce the gain of the analog filter 130, preventing the amplitude of the second analog signal from being too large, and ensuring that the active noise cancellation audio device 100 can operate stably in the initial state.

[0077] In some embodiments, the processing circuit 140 may send control instructions to the analog filter 130 based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter 130.

[0078] The first analog signal may reflect the degree to which the environmental noise and the noise-canceling audio cancel each other out, and the second analog signal may reflect the magnitude of the noise-canceling audio. In some embodiments, the control command may be a high-level signal, a pulse signal, or the like, and the specific type of the control command may be selected depending on the type of processing circuit 140.

[0079] In some embodiments, the processing circuitry 140 may adjust the frequency of the control command to adjust the gain and phase shift of the analog filter 130. Figure 4 details a specific implementation of the processing circuitry 140 in an exemplary manner.

[0080] FIG. 4 is a schematic diagram of an active noise cancellation audio device 100 according to some embodiments of the present disclosure.

[0081] As shown in FIG. 4, y(t) represents the second analog signal, e(t) represents the first analog signal, and the processing circuit 140 calculates the necessary coefficients (e.g., gain and phase shift) of the analog filter 130 based on the first analog signal e(t) and the second analog signal y(t), calculates the amplitude frequency response and phase frequency response of the analog filter 130, and generates control commands corresponding to the amplitude frequency response and phase frequency response, which can be sent to the analog filter 130. The analog filter 130 can adjust its own gain and phase shift based on the control command so that the actual gain and phase shift of the analog filter 130 approach the calculated gain and phase shift. For a specific implementation of adjusting the analog filter 130, please refer to the relevant contents of FIGS. 3A and 3B above, and therefore a description thereof will be omitted here.

[0082] In an embodiment of the present application, the processing circuit 140 generates a control command based on the environmental noise and the analog signal corresponding to the noise-canceling voice to adjust the gain and phase shift of the analog filter 130, thereby achieving an optimal response of the analog filter 130 to the environmental noise and further improving the noise cancellation effect.

[0083] In some embodiments, the processing circuit 140 may include a first analog-to-digital converter and a second analog-to-digital converter, where the first analog-to-digital converter samples the first analog signal to generate a first digital signal, and the second analog-to-digital converter samples the second analog signal to generate a second digital signal. Correspondingly, the processing circuit 140 can send control instructions to the analog filter 130 based on the first digital signal and the second digital signal.

[0084] In some embodiments, analog-to-digital converters (e.g., a first analog-to-digital converter, a second analog-to-digital converter) may sample analog signals (e.g., a first analog signal, a second analog signal) based on a predetermined sampling rate to generate discrete digital signals (e.g., a first digital signal, a second digital signal). Correspondingly, processing circuitry 140 may generate control instructions based on the first digital signal and the second digital signal. Illustratively, as shown in FIG. 4 , first analog-to-digital converter 141 samples first analog signal e(t) to generate first digital signal e(n), and second analog-to-digital converter 142 samples second analog signal y(t) to generate second digital signal y(n).

[0085] In some embodiments, the processing circuit 140 may calculate coefficients (e.g., gain and phase shift) of the analog filter 130 based on the first digital signal and the second digital signal using a noise cancellation algorithm, such as an adaptive filtering algorithm (Least Mean Square, LMS) or a filtered-x least mean square algorithm (FXLMS), and generate control commands corresponding to the coefficients.

[0086] In the embodiment of the present application, when an analog signal is converted into a digital signal by an analog-to-digital converter, both the analog filter 130 that performs signal processing in the analog domain and the processing circuit 140 that performs signal processing in the digital domain can be realized, thereby realizing a combination of analog and digital, and expanding the range of applications of the active noise cancellation audio device 100.

[0087] Because analog-to-digital conversion and signal processing require time, in some embodiments, the processing circuit 140 may periodically send control commands to the analog filter 130. Correspondingly, the switch gate circuit may adjust the resistance or capacitance of the response regulator each period to adjust and control the amplitude and phase frequency responses of the analog filter 130.

[0088] In some embodiments, the processing circuit 140 may determine the period for transmitting a control command based on one or more delay-influencing factors, such as the sampling rate and signal conversion time of the analog-to-digital converter 130, the update time of the switch gate circuit, and the processing time of the signal by the processing circuit 140. For example, if the sampling rate of the analog-to-digital converter is 16 kHz, the switch gate circuit takes about 0.06 ms to update per point, the analog filter 130 takes 1 ms to process the signal, and the delay of the analog-to-digital conversion and the switch gate circuit, etc., requires a delay of about 5 ms, the processing circuit 140 may determine that the period for transmitting a control command may be 1 s. The specific time parameters provided above are merely examples, and the present application is not particularly limited thereto.

[0089] In some embodiments, when the operation of the active noise cancellation audio device 100 is stable, the processing circuit 140 may stop sending control commands to the analog filter 130 and stop adjusting and controlling the amplitude frequency response and the phase frequency response of the analog filter 130. Furthermore, when the amplitude of the first analog signal is within a predetermined amplitude range, the processing circuit 140 may stop sending control commands to the analog filter 130. When the amplitude of the first analog signal is within the predetermined amplitude range, this may reflect that the first analog signal is close to zero, which may reflect that the active noise cancellation audio device 100 is in an ideal state for active noise cancellation and is stable in operation.

[0090] 4, the active noise cancellation audio device 100 may further include an amplifier 150 coupled to the analog filter 130 to perform amplification processing on the first analog signal e(t). In some embodiments, the active noise cancellation audio device 100 may not include the amplifier 150 and may perform amplification processing on the first analog signal e(t) using only the analog filter 130.

[0091] In some embodiments, the presence of a secondary channel response in an audio device affects the noise cancellation effect, so the active noise cancellation audio device 100 may compensate for the secondary response. The secondary response is the response of a secondary channel in an audio device and can reflect the influence on the audio signal of the audio transmission path from the speaker to the microphone. Figure 5 exemplarily illustrates in detail a specific implementation manner of compensating for the secondary response.

[0092] FIG. 5 is a schematic diagram of an active noise cancellation audio device 100 according to some embodiments of the present disclosure.

[0093] As shown in FIG. 5, y(t) represents the second analog signal;

number

number

number

[0094] An analog summer is an electronic device that performs an operation on multiple analog signals. In some embodiments, the analog summer may be an operational amplifier-based summing circuit, such as an inverting summer circuit or a non-inverting summer circuit. In some embodiments, a first analog summer may perform an addition operation on the first analog signal and an inverted second-order response signal to generate a third analog signal to compensate for the second-order response. The third analog signal may reflect a superposition of a sound wave in which the environmental noise and the noise-canceling sound have been canceled out and the inverted noise-canceling sound after passing through a secondary channel, i.e., the environmental noise with the second-order response compensation performed.

[0095] Further, as an example, as shown in FIG.

number

[0096]

number

[0097] where:

number

number

number

[0098] Correspondingly, in some embodiments, a first analog-to-digital converter samples the first analog signal to generate a first digital signal, and a third analog-to-digital converter samples the third analog signal to generate a third digital signal. The processing circuit 140 can send control instructions to the analog filter 130 based on the first digital signal and the third digital signal to adjust the amplitude frequency response and the phase frequency response of the analog filter 130 to compensate for the second-order response.

[0099] Illustratively, as shown in FIG. 5 above, the first analog-to-digital converter 141 samples the first analog signal e(t) to generate a first digital signal e(n), and the third analog-to-digital converter 143 samples the third analog signal e(t) to generate a second digital signal e(n).

number

number

number

[0100]

number

[0101] where w(n+1) is the coefficient of the analog filter 130 that currently needs to be updated, and w(n) is the last updated coefficient of the analog filter 130.

number

number

[0102] In some embodiments, when compensating for a second-order response, the processing circuit 140 determines the coefficients of the analog filter 130, and then sends a control command to the analog filter 130 to adjust the actual gain and phase shift of the analog filter 130 to the calculated updated coefficients, thereby enabling the analog filter 130 to approach an optimal response to environmental noise. For specific implementation methods for adjusting the analog filter 130, please refer to the relevant content of Figures 3A and 3B above, and therefore further description will be omitted here.

[0103] In the embodiment of the present application, the second-order response is compensated using an analog adder, thereby achieving signal compensation in the analog domain and avoiding the delay caused by signal processing in the digital domain, thereby ensuring that the analog filter 130 can process external environmental noise in a timely manner, improving the accuracy of noise cancellation, and further improving the noise cancellation effect of the active noise cancellation audio device 100.

[0104] In some embodiments, if the active noise cancellation audio device 100 is an open-type audio device (i.e., speakers close to but not occluding the ears), the response of the channel between the user's ear canal and the microphone affects the noise cancellation effect, so the active noise cancellation audio device 100 may construct a transfer function between the user's ear canal and the microphone to perform compensation, i.e., open-type response compensation.

[0105] The transfer function between the user's ear canal and the microphone may represent the effect on the transmission of sound between the user's ear canal and the microphone, and in some embodiments, the transfer function between the user's ear canal and the microphone may be obtained by experimental testing or based on a statistical model or a neural network model.

[0106] For example, a response H1 from the speaker to the microphone and a response H2 from the speaker to the user's ear canal are obtained by a test (e.g., an artificial head test), and a relation between the responses H1 and H2 is calculated.

number

number

number

[0107] In some embodiments, the active noise cancellation audio device 100 may include a first analog adder, a third analog-to-digital converter, and a fourth analog-to-digital converter. The fourth analog-to-digital converter may sample the second-order response signal to generate a fourth digital signal for signal processing by the processing circuit 140. For specific implementations of the analog adder and the analog-to-digital converter, please refer to the relevant descriptions of FIGS. 4 and 5 above, and therefore further description will be omitted here. The processing circuit 140 may determine a fifth digital signal based on the third digital signal and a transfer function between the user's ear canal and the microphone, and send a control command to the analog filter 130 based on the fourth digital signal and the fifth digital signal to adjust the amplitude frequency response and phase frequency response of the analog filter 130 when compensating for the second-order response and the open-type response. Furthermore, in some embodiments, the processing circuit 140 may perform a summation operation on the fourth digital signal and the fifth digital signal to obtain a sixth digital signal, and send a control command to the analog filter 130 based on the third digital signal and the sixth digital signal.

[0108] The third digital signal may reflect environmental noise with secondary response compensation, the fourth digital signal may reflect noise-canceled audio with secondary response added, the fifth digital signal may reflect sound waves obtained by performing secondary response compensation on the noise-canceled audio under the influence of open-type response, and the sixth digital signal may reflect sound waves obtained by performing secondary response compensation and open-type response compensation on the noise-canceled audio. Figure 6 exemplarily illustrates a specific implementation of open-type response compensation.

[0109] FIG. 6 is a schematic diagram of an active noise cancellation audio device 100 according to some embodiments of the present disclosure.

[0110] As shown in Figure 6,

number

number

number

number

number

[0111]

number

[0112] where:

number

number

number

number

number

number

number

number

[0113]

number

[0114] where w'(n+1) is the coefficient of the analog filter 130 that needs to be updated this time, and w'(n) is the last updated coefficient of the analog filter 130.

number

number

number

[0115] In some embodiments, when compensating for the second-order response and the open-type response, the processing circuit 140 determines the coefficients of the analog filter 130, and then sends a control command to the analog filter 130 to make the actual gain and phase shift of the analog filter 130 approach the calculated updated coefficients, so that the analog filter 130 can approach an optimal response to environmental noise. For specific implementation methods for adjusting the analog filter 130, please refer to the relevant content of Figures 3A and 3B above, and therefore, description thereof will be omitted here.

[0116] In an embodiment of the present application, when the active noise cancellation audio device 100 is an open-type audio device, the transfer function between the user's ear canal and the microphone can be compensated for, thereby improving the accuracy of noise cancellation and ensuring the noise cancellation effect of the active noise cancellation audio device 100.

[0117] 7 is a flow chart of an active noise cancellation method according to some embodiments of the present disclosure. In some embodiments, flow 700 may be performed by active noise cancellation audio device 100.

[0118] In some embodiments, flow 700 may include steps 710 through 740.

[0119] In step 710, the active noise cancellation audio device generates a noise cancellation sound. In some embodiments, the noise cancellation sound may cancel out the ambient noise to achieve a noise cancellation effect. Step 710 may be performed by the speaker 110. For specific implementation methods, please refer to the related descriptions of Figures 1 to 6, and therefore, further description will be omitted here.

[0120] In step 720, the active noise cancellation audio device collects the environmental noise and the noise cancellation audio and generates a first analog signal. In some embodiments, the first analog signal may reflect the degree to which the environmental noise and the noise cancellation audio cancel each other out. Step 720 may be performed by the microphone 120. For specific implementation methods, please refer to the related descriptions of Figures 1 to 6, and therefore further description will be omitted here.

[0121] In step 730, the active noise cancellation audio device uses an analog filter to apply gain to the first analog signal to generate a second analog signal that generates a noise-canceled sound. In some embodiments, the second analog signal may drive a speaker to generate the noise-canceled sound. Step 730 may be performed by the analog filter 130. Specific implementation methods may refer to the related descriptions of Figures 1 to 6, and will not be described here.

[0122] In step 740, the active noise cancellation audio device transmits a control command based on the first analog signal and the second analog signal to adjust the gain and phase shift of the analog filter. In some embodiments, the active noise cancellation audio device may transmit a control command to the analog filter to drive the analog filter to adjust the gain and phase shift. Step 740 may be performed by the analog filter 130. For specific implementation methods, please refer to the related descriptions of Figures 1 to 6, and therefore further description will be omitted here.

[0123] In the embodiments of the present specification, an analog filter is used to adjust the amplitude and phase of the analog signal, thereby generating a noise-canceling sound, which reduces the delay caused by the signal conversion (e.g., digital-to-analog conversion) stage and digital filter processing, allowing for a timely noise-canceling response, thereby improving the noise-canceling effect.

[0124] In addition, the active noise cancellation audio method according to the embodiments of the present specification can adjust the gain and phase shift of the analog filter based on the environmental noise and the analog signal corresponding to the noise cancellation audio, so as to achieve an optimal response of the analog filter to the environmental noise, and further improve the noise cancellation effect.

[0125] In some embodiments, adjusting the gain and phase shift of the analog filter may include controlling the active noise cancellation audio device to dynamically adjust the gain of the analog filter in accordance with changes in the amplitude of the first analog signal over a specific time range. In this way, the analog filter can avoid providing too much or too little gain at a specific time, thereby achieving an optimal response of the analog filter to environmental noise, thereby improving the noise cancellation effect of the active noise cancellation audio device.

[0126] In some embodiments, flow 700 may further include the active noise cancellation audio device sampling a first analog signal to generate a first digital signal and sampling a second analog signal to generate a second digital signal. Step 740 may include the active noise cancellation audio device transmitting a control command based on the first digital signal and the second digital signal. The sampling steps may be performed by the first analog-to-digital converter and the second analog-to-digital converter, respectively. For specific implementations, please refer to the relevant contents of Figures 1 to 6, and therefore further description will be omitted here.

[0127] In the embodiment of the present specification, a control command is generated based on the environmental noise and the analog signal corresponding to the noise cancellation voice, and the gain and phase shift of the analog filter are adjusted to achieve an optimal response of the analog filter to the environmental noise, thereby further improving the noise cancellation effect.

[0128] In some embodiments, the flow 700 may further include a step in which the active noise cancellation audio device adjusts the resistance or capacitance of a response regulator in the analog filter according to the control command, so as to change the amplitude frequency response and phase frequency response of the analog filter, which may be performed by a switch gate circuit in the analog filter. For specific implementation methods, please refer to the related descriptions of Figures 3A and 3B, and therefore further description will be omitted here.

[0129] In some embodiments, the response regulator may include one or more phase modulation units, each of which may include at least one variable resistor or at least one variable capacitor. Correspondingly, adjusting the resistance or capacitance of the response regulator in the analog filter based on the control command may include adjusting the resistance of the variable resistor or the capacitance of the variable capacitor based on the control command. This step may be performed by a switch gate circuit in the analog filter. For specific implementation methods, please refer to the related descriptions of Figures 3A and 3B, and therefore further description will be omitted here.

[0130] In the embodiments of the present specification, the resistance value of the variable resistor or the capacitance value of the variable capacitor can be adjusted to control the amplitude frequency response and phase frequency response of the analog filter, avoiding the analog filter providing too large or too small a gain at a particular time, and achieving an optimal response of the analog filter to environmental noise, thereby improving the noise cancellation effect of the active noise cancellation audio device.

[0131] In some embodiments, flow 700 may further include the active noise cancellation audio device generating a third analog signal based on the first analog signal, the second analog signal, and a secondary response corresponding to the second analog signal, where the secondary response is a response from the speaker to the microphone. The active noise cancellation audio device may further sample the first analog signal to generate a first digital signal and sample the third analog signal to generate a third digital signal. Step 740 above may include transmitting a control command based on the first digital signal and the third digital signal.

[0132] In some embodiments, the step of generating a third analog signal may be performed by an analog adder, and the step of sampling the third analog signal may be performed by a third analog-to-digital converter. For specific implementation methods, please refer to the related descriptions in Figures 5 and 6, and therefore further description will be omitted here.

[0133] In the embodiments of the present specification, by compensating for the second-order response in the analog domain, the delay caused by signal processing in the digital domain can be avoided, thereby ensuring that the active noise cancellation audio device can process external environmental noise in a timely manner, and also improving the accuracy of noise cancellation and further improving the noise cancellation effect.

[0134] In some embodiments, if the active noise cancellation audio device is an open-back audio device, the transfer function between the user's ear canal and the microphone may be constructed to provide compensation, i.e., open-back response compensation.

[0135] In some embodiments, flow 700 may further include the active noise cancellation audio device generating a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal. The second-order response is the response from the speaker to the microphone. The active noise cancellation audio device may sample the third analog signal to generate a third digital signal and sample the second analog signal with the added second-order response to generate a fourth digital signal. Step 740 above may include the active noise cancellation audio device determining a fifth digital signal based on the third digital signal and a transfer function between the user's ear canal and the microphone. The active noise cancellation audio device may transmit control commands based on the fourth digital signal and the fifth digital signal.

[0136] In some embodiments, the step of sampling the second analog signal to which the second-order response is added may be performed by a fourth analog-to-digital converter, and the step of determining the fifth digital signal may be performed by a processing circuit. For specific implementation methods, please refer to the related description of Figure 6, and therefore, further description will be omitted here.

[0137] In some embodiments, the transfer function between the user's ear canal and the microphone is obtained by experimental testing, or based on a statistical model or a neural network model. In some embodiments, the flow 700 may further include the active noise cancellation device periodically sending a control command.

[0138] In the embodiments of the present specification, when the active noise cancellation audio device is an open-type audio device, it can compensate for the transfer function between the user's ear canal and the microphone, improve the accuracy of noise cancellation, and ensure the noise cancellation effect.

[0139] Possible beneficial effects of embodiments herein include, but are not limited to, (1) and (2): (1) By using an analog filter to directly process (e.g., gain or phase shift) an analog signal corresponding to noise cancellation audio, delays due to signal conversion (e.g., digital-to-analog conversion) and digital filter processing can be reduced, allowing the audio device to provide a timely noise cancellation response and improve noise cancellation effectiveness; (2) The processing circuit adjusts the gain and phase shift of the analog filter based on the environmental noise and the analog signal corresponding to noise cancellation audio to achieve an optimal response of the analog filter to the environmental noise and further improve noise cancellation effectiveness.

[0140] Although the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure above is merely provided by way of example and is not intended to limit the present specification. Although not expressly described herein, those skilled in the art may make various changes, improvements, and modifications to the present specification. These changes, improvements, and modifications are intended to be suggested by the present specification and are therefore within the spirit and scope of the exemplary embodiments of the present specification.

[0141] Furthermore, certain terms are used herein to describe embodiments herein. For example, "one embodiment," "one embodiment," and / or "some embodiments" refer to particular features, structures, or characteristics associated with at least one embodiment herein. Therefore, it is emphasized and understood that references to "one embodiment" or "one embodiment" or "one alternative embodiment" more than once in various parts of this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics in one or more embodiments herein may be combined as appropriate.

[0142] Additionally, unless expressly stated in the claims, the enumerated order of processing elements or sequences described herein, the use of alphanumeric characters, or the use of other designations does not limit the order of the procedures and methods herein. While the above disclosure has set forth through various examples what are presently believed to be various useful embodiments of the invention, it should be understood that such details are merely illustrative, and that the appended claims are not limited to the disclosed embodiments, but rather are intended to cover all modifications and equivalent combinations within the spirit and scope of the embodiments herein. For example, the system assembly described above may be implemented by a hardware device, or may be implemented as a software-only solution, e.g., by installing the described system on an existing server or mobile device.

[0143] Similarly, in the foregoing description of embodiments herein, it should be understood that various features may be grouped together in a single embodiment, drawing, or description for the purpose of simplifying the description and facilitating an understanding of one or more embodiments of the invention. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed subject matter requires more features than are recited in each claim. In fact, an embodiment may include fewer than all features of a single embodiment disclosed above.

[0144] In some embodiments, numbers describing the number of components and attributes are used, and it should be understood that the numbers describing such embodiments are modified in some instances by the modifiers "about," "approximately," or "generally." Unless otherwise specified, "about," "approximately," or "generally" indicates that the number may vary by ±20%. Thus, in some embodiments, all numerical parameters used in the specification and claims are approximations that may vary depending on the specific characteristics of a particular embodiment. In some embodiments, numerical parameters should be used with the stated number of significant digits and with ordinary rounding techniques. While in some embodiments the numerical ranges and parameters used to determine ranges are approximations, in specific embodiments, such numerical values ​​are set as precisely as possible.

[0145] All patents, patent applications, published patent applications, and other materials, such as papers, books, specifications, publications, and documents, referenced herein are incorporated herein by reference in their entirety, except for prosecution history documents that are inconsistent with or inconsistent with the content of this specification and documents that may have a limiting effect on the broadest scope of the claims herein (now or later related to this specification). Further, in the event that an explanation, definition, and / or term usage in the accompanying materials hereto is inconsistent with or inconsistent with the content set forth herein, the explanation, definition, and / or term usage in this specification shall control.

[0146] Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments herein. Other variations may be within the scope of the present disclosure. Thus, by way of example, and not of limitation, alternative configurations of the embodiments herein may be considered consistent with the teachings herein. Thus, the embodiments herein are not limited to the embodiments expressly introduced and described herein. [Explanation of symbols]

[0147] 100 Active Noise Cancellation Audio Device 110 speakers 120 microphones 130 Analog Filter 140 Processing Circuit 141 first analog-to-digital converter 142 Second Analog-to-Digital Converter 143 Third Analog-to-Digital Converter 144 Fourth Analog-to-Digital Converter 150 Amplifier 160 Analog Adder

Claims

1. a speaker that generates noise-reduced audio; a microphone that collects environmental noise and the noise-reduced audio and generates a first analog signal; an analog filter that applies gain to the first analog signal to generate a second analog signal that drives the speaker to produce the noise-reduced sound; a processing circuit that sends control instructions to the analog filter based on the first analog signal and the second analog signal to adjust a gain and a phase shift of the analog filter; Including, the processing circuitry includes a first analog-to-digital converter and a second analog-to-digital converter; the first analog-to-digital converter samples the first analog signal to generate a first digital signal, and the second analog-to-digital converter samples the second analog signal to generate a second digital signal; the processing circuit sends a control command to the analog filter based on the first digital signal and the second digital signal. Active noise reduction audio device.

2. The processing circuitry adjusting the gain and phase shift of the analog filter comprises:

2. The active noise reduction audio device of claim 1, wherein the processing circuit controls the analog filter to dynamically adjust its gain in accordance with changes in the amplitude of the first analog signal within a specific time range.

3. 2. The active noise reduction audio device of claim 1, wherein the analog filter includes a switch gate circuit and a response regulator, and the switch gate circuit adjusts a resistance value or a capacitance value of the response regulator based on the control command to change the amplitude frequency response and the phase frequency response of the analog filter.

4. The response regulator includes one or more phase modulation units, each phase modulation unit including at least one variable resistor or at least one variable capacitor; The switch gate circuit adjusts the resistance value or the capacitance value of the response regulator based on the control command, 4. The active noise reduction audio device according to claim 3, wherein the switch gate circuit adjusts the resistance value of the variable resistor or the capacitance value of the variable capacitor based on the control command.

5. further comprising a first analog adder and a third analog-to-digital converter; the first analog summer generates a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal, the second-order response being a response from the speaker to the microphone; the third analog-to-digital converter samples the third analog signal to generate a third digital signal; The processing circuitry sending a control command to the analog filter comprises:

5. The active noise reducing audio device of claim 1, wherein the processing circuitry sends a control command to the analog filter based on the first digital signal and the third digital signal.

6. 2. The active noise reduction audio device of claim 1, further comprising a fixing structure that fixes the speaker and the microphone to positions near the user's ears that do not block the user's ear canals.

7. further comprising a first analog summer, a third analog-to-digital converter, and a fourth analog-to-digital converter; the first analog summer generates a third analog signal based on the first analog signal, the second analog signal, and a second-order response corresponding to the second analog signal, the second-order response being a response from the speaker to the microphone; the third analog-to-digital converter samples the third analog signal to generate a third digital signal; the fourth analog-to-digital converter samples the second analog signal to which the second-order response has been added to generate a fourth digital signal; The processing circuitry sending a control command to the analog filter comprises: the processing circuit determining a fifth digital signal based on the third digital signal and a transfer function between the user's ear canal and the microphone; 7. The active noise reducing audio device of claim 6, wherein the processing circuitry sends a control command to the analog filter based on the fourth digital signal and the fifth digital signal.

8. 8. The active noise reducing audio device of claim 7, wherein the transfer function between the user's ear canal and the microphone is obtained by experimental testing or based on a statistical model or a neural network model.

9. generating a noise-reduced audio; collecting environmental noise and the noise-reduced audio to generate a first analog signal; applying gain to the first analog signal using an analog filter to generate a second analog signal that generates the noise-reduced sound; sending control commands based on the first analog signal and the second analog signal to adjust a gain and a phase shift of the analog filter; sampling the first analog signal to generate a first digital signal; sampling the second analog signal to generate a second digital signal; and sending a control command to the analog filter based on the first digital signal and the second digital signal.

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