Electronic device for performing active noise cancellation and control method thereof

Abstract

Disclosed is a method performed by an electronic device for performing active noise cancellation. The method includes the steps of: obtaining a noise signal; inputting a plurality of audio samples constituting the noise signal to a filter including a plurality of stages; and generating an anti-noise signal for attenuating the noise signal by using data output from the plurality of stages.

Description

Electronic device performing active noise cancellation and control method thereof

[0001] The present disclosure relates to an electronic device and a control method thereof, and more particularly, to an electronic device performing active noise cancellation (ANC) and a control method thereof.

[0002] Electronic devices may provide functions related to audio signal processing. For example, the electronic device may provide a calling function that collects and transmits audio signals, a recording function that records audio signals, etc.

[0003] Electronic devices that output audio may incorporate various noise-cancelling and noise-suppression technologies to distinguish between audio signals. For example, headphones can capture ambient noise through a microphone connected to a noise-cancelling circuit and output an anti-noise signal in the opposite phase to the captured noise. The user hears both the ambient noise and the noise in the opposite phase, resulting in a noise-cancelling effect.

[0004] The above information may be provided solely as background information to aid in understanding the present disclosure. No judgment or assertion is made as to whether any of the above information is applicable as prior art in connection with the present disclosure.

[0005] The present disclosure may be intended to address at least the aforementioned problems or shortcomings and provide at least the advantages described below. Accordingly, the present disclosure may disclose an electronic device for active noise cancellation and a control method thereof.

[0006] Additional embodiments may be described below. Furthermore, some of the additional embodiments may be made clear by the description of the present disclosure or the embodiments described below.

[0007] A method of controlling an electronic device performing active noise cancellation according to one or more embodiments of the present disclosure includes the steps of obtaining a noise signal, inputting a plurality of audio samples constituting the noise signal into a filter including a plurality of stages, and generating an anti-noise signal for attenuating the noise signal using data output from the plurality of stages.

[0008] The step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages may input the plurality of audio samples to each of the plurality of stages at different sampling rates.

[0009] The above control method may further include a step of compressing the original filter to a different level in each of the plurality of stages.

[0010] Each of the above multiple stages may include the same number of coefficients.

[0011] The step of inputting audio samples constituting the above noise signal into a filter including a plurality of stages may input the same number of audio samples to each of the plurality of stages.

[0012] The step of inputting a plurality of audio samples constituting the above noise signal into a filter divided into a plurality of stages may include downsampling adjacent audio samples into one audio sample, and inputting the downsampled one audio sample into one of the plurality of stages.

[0013] The filter includes a first stage and a second stage, and the step of inputting a plurality of audio samples constituting the noise signal into a filter divided into a plurality of stages may include inputting two audio samples into a first buffer memory corresponding to the first stage, and when the two audio samples are input into the first buffer memory, down-sampling two audio samples from among the audio samples stored in the first buffer memory in the oldest order into one audio sample, and inputting the down-sampled one audio sample into a second buffer memory corresponding to the second stage.

[0014] The above control method may further include a step of inputting audio samples stored in the first buffer memory into a first stage of the filter.

[0015] The filter may further include a first filter configured to filter an external noise signal acquired through an external microphone, a second filter configured to generate a first feedback signal from an internal noise signal acquired through an internal microphone and having a coefficient dynamically adjusted, and a third filter configured to generate a second feedback signal from the internal noise signal acquired through the internal microphone and having a fixed coefficient.

[0016] The third filter may further include a feedback module that excludes the output of the third filter from the internal noise signal obtained through the internal microphone.

[0017] The above control method may further include a step of identifying a path through which sound output from a speaker reaches an internal microphone located inside the electronic device, and a step of determining a coefficient of the third filter using the identified path.

[0018] The step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages may include inputting the noise signal into the first filter and the second filter while determining the coefficients of the second feedback filter.

[0019] An electronic device for performing active noise cancellation according to one or more embodiments of the present disclosure, comprising: at least one microphone; a speaker; a memory storing one or more computer programs; and a processor collectively connected to the at least one microphone, the speaker, and the memory; wherein the one or more computer programs, when individually or collectively executed by the one or more processors, control the speaker to cause the electronic device to obtain a noise signal through the at least one microphone, input a plurality of audio samples constituting the noise signal into a filter including a plurality of stages, and output an anti-noise signal for attenuating the noise signal using data output from the plurality of stages.

[0020] The processor can input the plurality of audio samples to each of the plurality of stages at different sampling rates.

[0021] The one or more computer programs, when individually or collectively executed by the one or more processors, may cause the electronic device to compress the original filter to a different level in each of the plurality of stages.

[0022] Each of the above multiple stages may include the same number of coefficients.

[0023] The one or more computer programs, when individually or collectively executed by the one or more processors, may cause the electronic device to input the same number of audio samples to each of the plurality of stages.

[0024] The processor can downsample adjacent audio samples into one audio sample and input the downsampled audio sample into one of the plurality of stages.

[0025] The filter includes a first stage and a second stage, and the processor can input two audio samples into a first buffer memory corresponding to the first stage, and when the two audio samples are input into the first buffer memory, down-sample two audio samples from among the audio samples stored in the first buffer memory in the oldest order into one audio sample, and input the down-sampled one audio sample into a second buffer memory corresponding to the second stage.

[0026] One or more non-volatile computer-readable storage media, wherein the storage media store one or more computer programs, the computer programs including computer-executable instructions, wherein when the computer-executable instructions are individually or collectively executed by one or more processors of an electronic device, the electronic device can obtain a noise signal, input a plurality of audio samples constituting the noise signal into a filter including a plurality of stages, and generate an anti-noise signal for attenuating the noise signal using data output from the plurality of stages.

[0027] According to an embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for causing an electronic device to perform active noise cancellation, one of the above-described and below-described methods.

[0028] Other aspects, advantages and key features of the present disclosure will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings, in which various embodiments of the present disclosure are described.

[0029] Advantages, features and aspects of specific embodiments of the present disclosure may become apparent from the accompanying drawings and the description below.

[0030] FIG. 1 is a diagram for explaining an audio signal processing system according to an embodiment of the present disclosure.

[0031] FIG. 2 and FIG. 3 are drawings illustrating noise removal according to one or more embodiments of the present disclosure.

[0032] FIG. 4 is a block diagram illustrating the configuration of an electronic device according to an embodiment of the present disclosure.

[0033] FIG. 5 is a drawing for explaining the operation of a filter module according to an embodiment of the present disclosure.

[0034] FIG. 6 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0035] FIG. 7 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0036] FIG. 8 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0037] FIG. 9 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0038] FIG. 10 is a drawing for explaining the operation of a plurality of modules according to an embodiment of the present disclosure.

[0039] FIG. 11 is a drawing for explaining a method for an electronic device according to an embodiment of the present disclosure to compress a filter.

[0040] FIG. 12 is a diagram illustrating a method for an electronic device according to an embodiment of the present disclosure to input an audio sample into a filter.

[0041] FIGS. 13, 14, 15, and 16 are diagrams illustrating a method for an electronic device according to one or more embodiments of the present disclosure to downsample audio samples and input the downsampled audio samples to each stage of a filter.

[0042] FIG. 17 and FIG. 18 are diagrams showing noise performance according to combinations of filter modules according to various embodiments of the present disclosure.

[0043] FIG. 19 and FIG. 20 are diagrams showing noise performance according to the degree of compression of a filter module according to various embodiments of the present disclosure.

[0044] FIG. 21 is a drawing for explaining a control method of an electronic device according to an embodiment of the present disclosure;

[0045] Throughout the drawings, the same reference numbers may be used to indicate identical or similar components, features and structures.

[0046] The following description, accompanied by the accompanying drawings, may be provided to assist in a comprehensive understanding of various embodiments of the present disclosure defined by the appended claims and their equivalents. While it includes numerous specific details to aid in such understanding, such details may be considered merely exemplary. Accordingly, those skilled in the art will recognize that various changes and modifications may be made to the various embodiments described herein without departing from the spirit and scope of the present disclosure. Furthermore, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0047] The terms and words used in the following description and claims are not limited to their dictionary meanings and can be used by the inventors to ensure a clear and consistent understanding of the invention. Therefore, those skilled in the art will readily understand that the following description of various embodiments of the present disclosure is intended solely for illustrative purposes and is not intended to limit the present disclosure, which is defined by the appended claims and their equivalents.

[0048] Singular forms are understood to include plural references unless the context clearly requires otherwise. For example, a reference to "a surface of a component" may include reference to one or more such surfaces.

[0049]

[0050] In this disclosure, expressions such as “has,” “can have,” “includes,” or “may include” indicate the presence of a corresponding feature (e.g., a component such as a number, function, operation, or part), and do not exclude the presence of additional features.

[0051] In this disclosure, expressions such as “A or B,” “at least one of A and / or B,” or “one or more of A or / and B” can include all possible combinations of the listed items. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” can all refer to (1) including at least one A, (2) including at least one B, or (3) including both at least one A and at least one B.

[0052] The expressions “first,” “second,” “first,” or “second,” etc., used in this disclosure can describe various components, regardless of order and / or importance, and are only used to distinguish one component from another, but do not limit the components.

[0053] When it is said that a component (e.g., a first component) is “(operatively or communicatively) coupled with / to” or “connected to” another component (e.g., a second component), it should be understood that said component may be directly coupled to said other component, or may be coupled via another component (e.g., a third component).

[0054] On the other hand, when it is said that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component), it can be understood that no other component (e.g., a third component) exists between said component and said other component.

[0055] The expression "configured to" used in the present disclosure may be used interchangeably with, for example, "suitable for," "having the capacity to," "designed to," "adapted to," "made to," or "capable of." The term "configured to" may not necessarily mean only "specifically designed to" in terms of hardware.

[0056] Instead, in some contexts, the phrase "a device configured to" may mean that the device is "capable of" doing something in conjunction with other devices or components. For example, the phrase "a processor configured (or set) to perform A, B, and C" may mean a dedicated processor (160) for performing the actions, or a general-purpose processor (160) (e.g., a CPU or application processor) that can perform the actions by executing one or more software programs stored in a memory device.

[0057] In the embodiments, a 'module' or 'part' performs at least one function or operation, and may be implemented as hardware or software, or as a combination of hardware and software. Furthermore, a plurality of 'modules' or 'parts' may be integrated into at least one module and implemented as at least one processor, except for a 'module' or 'part' that needs to be implemented as a specific hardware.

[0058] The present disclosure relates to a method for removing noise by performing an “Active Noise Cancellation” operation.

[0059] In the present disclosure, "active noise cancellation" refers to an operation of canceling out noise by outputting an anti-noise signal with an opposite phase to the noise using one or more filters. In the present disclosure, an electronic device can obtain an anti-noise signal by passing audio samples constituting the noise signal through a filter.

[0060] In the present disclosure, a "filter" refers to a digital filter that generates a fixed-length response to an input signal. The filter may include a certain number of coefficients. When an audio sample is input, the filter may generate an output signal through a convolution operation between the coefficients and the input audio sample. In the present disclosure, the "coefficients" of the filter may be replaced with expressions representing the same or similar concepts, such as a tap of the filter, a "filter coefficient" of the filter, a "weight" of the filter, a "parameter" of the filter, etc.

[0061] In this disclosure, "audio sample" refers to an individual data point converted into discrete digital data through a sampling process of an audio signal. The sampling process refers to the process of measuring an analog audio signal at specific intervals and recording each measured value in digital form. An audio sample is defined by a sampling rate (the rate indicating the number of times an audio sample is measured per second) and a bit depth (the number of bits used to represent the audio sample).

[0062] According to one or more embodiments of the present disclosure, the filter may be a Finite Impulse Response (FIR) filter. According to one or more embodiments of the present disclosure, the filter may be an Infinite Impulse Response (IIR) filter. According to one or more embodiments of the present disclosure, an electronic device may perform active noise removal by combining a plurality of FIR filters. According to one or more embodiments of the present disclosure, an electronic device may perform active noise removal by combining one or more FIR filters and one or more IIR filters.

[0063] In the present disclosure, the "span" of a filter may indicate the number of audio samples required for the filter to perform a calculation. In other words, the length of a filter may indicate how many previous audio samples the filter calculates for an input signal. In the present disclosure, the "length" of a filter may be replaced with expressions representing the same or similar concepts, such as the "order" of the filter, the "size" of the filter, etc.

[0064] In the present disclosure, a filter may include multiple stages. In the present disclosure, a "stage" of a filter may refer to an individual step in which the filter processes input data. Each stage of the filter may sequentially apply a specific operation to the input data. Specifically, each stage of the filter may refer to a unit that performs a convolution operation with audio samples constituting a noise signal. For example, a first group of input audio samples may perform a first convolution operation with a first stage of the filter, and a second group of input audio samples may perform a second convolution operation with a second stage. In the present disclosure, "stage" may be replaced with expressions representing the same / similar concepts, such as "step," "interval," "region," "time interval," "time domain," and "processing unit."

[0065] According to one or more embodiments of the present disclosure, each stage of the filter can be compressed to a different level to reduce the computational resource consumption of the filter while maintaining the length of the filter.

[0066] In the present disclosure, “compression” of a filter means an operation of reducing the computational consumption of a filter by replacing several coefficients of the filter with a single coefficient.

[0067] According to one or more embodiments of the present disclosure, an electronic device may replace an average value of several coefficients with a value of one coefficient. Alternatively, the electronic device may replace a value of a highest coefficient among several coefficients with a value of one coefficient. Alternatively, the electronic device may replace a weighted average value of several coefficients with a value of one coefficient. Alternatively, the electronic device may use statistical techniques to replace a value of a coefficient with a value of a most characteristic coefficient. Alternatively, the electronic device may use an optimization algorithm, such as a least squares method, to remove coefficients with low significance and replace values ​​of coefficients with high significance with a value of one coefficient.

[0068] In the present disclosure, the term “compression” of a filter may be replaced with an expression representing the same / similar concept, such as “coefficient sharing” of a filter.

[0069] In the present disclosure, each stage of the filter can be compressed to a specific "level." The level may indicate the degree to which the coefficients included in each stage of the filter are compressed. A higher compression level may increase the number of multiple coefficients replaced by a single coefficient.

[0070] For example, if the first stage is compressed to the first level, the eight coefficients included in the first stage can be compressed to four coefficients. And, if the second stage is compressed to the second level, the 16 coefficients included in the second stage can be compressed to four coefficients.

[0071] In the present disclosure, “compression level” may be replaced with an expression indicating the same / similar concept, such as “compression degree.”

[0072] Meanwhile, the various elements and areas in the drawings are schematically drawn. Therefore, the technical concept of the present invention is not limited by the relative sizes or spacing depicted in the attached drawings.

[0073] Hereinafter, with reference to the attached drawings, embodiments according to the present disclosure will be described in detail so that a person having ordinary knowledge in the technical field to which the present disclosure pertains can easily implement the present disclosure.

[0074] It can be understood that the blocks and combinations of flowcharts in each flowchart can be performed by one or more computer programs containing instructions. One or more computer programs may be stored entirely in a single memory device, or one or more computer programs may be stored in separate parts in multiple different memory devices.

[0075] The functions or tasks described may be performed by a single processor or a combination of processors. The single processor or processor combination is a circuit that performs processing and may include an application processor (AP, e.g., a central processing unit (CPU)), a communications processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU, e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, a connection chip, a sensor controller, a touch controller, a fingerprint sensor controller, a display driver integrated circuit (IC), an audio codec chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on a chip (SoC), an IC, or similar circuits.

[0076] FIG. 1 is a diagram for explaining an audio signal processing system according to an embodiment of the present disclosure.

[0077] Referring to FIG. 1, an audio signal processing system (10) may include an electronic device (100) and an external device (200).

[0078] The electronic device (100) may be a device for playing audio. According to one or more embodiments of the present disclosure, the electronic device (100) may be an earphone having an active noise canceling function. According to one or more embodiments of the present disclosure, the electronic device (100) may be a mobile device that can be carried by a user, a wearable device that can be worn on a user's body, a smart device having its own audio processing function, a TWS (true wireless) device, a hearable device, intelligent earbuds, intelligent headphones, or an artificial intelligence speaker, and may be implemented in various forms without being limited thereto.

[0079] In the present disclosure, the electronic device (100) can receive an audio signal corresponding to a sound acquired from the outside of the electronic device (100) through a microphone configured as a part of the electronic device (100). The electronic device (100) can be directly connected to an external device (200) through a connection terminal or wirelessly through a wireless communication module (e.g., a Bluetooth communication module) to transmit an audio signal acquired in the electronic device (100) or receive an audio signal from the external device (200). The electronic device (100) can receive a control signal (e.g., a noise removal operation signal received through an input button) related to the audio signal acquired from the external device (200). According to one embodiment, the electronic device (100) can receive information related to processing of an audio signal from the external device (200).

[0080] In the present disclosure, the electronic device (100) may perform various processing on the received audio signal. For example, the electronic device (100) may perform noise processing (e.g., noise or echo reduction), application of one or more filters, change of sampling rate, interpolation processing, amplification or attenuation of all or part of a frequency band, channel change (e.g., switching between mono and stereo), mixing, or extraction of a specified signal on one or more audio signals.

[0081] According to one or more embodiments of the present disclosure, one or more audio signal processing functions of the electronic device (100) may be implemented by a Digital Signal Processor (DSP). According to one or more embodiments of the present disclosure, one or more audio signal processing functions of the electronic device (100) may be implemented by a dedicated Neural Processing Unit (NPU).

[0082] In the present disclosure, the electronic device (100) can output an audio signal to the outside of the electronic device (100) through a speaker configured as a part of the electronic device (100).

[0083] In the present disclosure, the external device (200) may be a device for processing audio. According to one or more embodiments of the present disclosure, the external device (200) may be a device capable of controlling the electronic device (100). In various embodiments, the external device (200) may be a mobile device that can be carried by a user. For example, the external device (200) may include at least one of a smartphone, a tablet personal computer (PC), a mobile phone, an e-book reader, a laptop personal computer (PC), a netbook computer, a personal digital assistant (PDA), a portable multimedia player (PMP), and an MP3 player. Of course, the present disclosure is not limited to the above examples.

[0084] In the present disclosure, an external device (200) may be directly connected to an electronic device (100) through a connection terminal or wirelessly through a wireless communication module (e.g., a Bluetooth communication module) to receive an audio signal from the electronic device (100) or transmit an audio signal to the electronic device (100). According to one or more embodiments of the present disclosure, the external device (200) may transmit a control signal (e.g., a noise removal operation signal transmitted through an input button) related to an audio signal transmitted to the electronic device (100). According to one embodiment, the external device (200) may transmit information related to processing of an audio signal to the electronic device (100).

[0085] In the present disclosure, the external device (200) can perform various processing on an audio signal. For example, the external device (200) can perform noise processing (e.g., noise or echo reduction), application of one or more filters, change of sampling rate, interpolation processing, amplification or attenuation of all or part of a frequency band, channel change (e.g., switching between mono and stereo), mixing, or extraction of a specified signal on one or more audio signals.

[0086] In the present disclosure, the audio signal processing system (10) can perform audio signal processing for various purposes. The audio signal processing system (10) can analyze the environment, context, or conditions in which the electronic device (100) or the external device (200) is being used to determine what audio signal processing to perform. For example, the audio signal processing system (10) can process an audio signal to perform at least one of active noise cancellation, sound separation, sound enhancement, selective listening, acoustic echo cancellation, ambient pass-through, beamforming, and selective filtering. For example, the audio signal processing system (10) of the present disclosure can analyze an audio signal to perform at least one of sound event detection, such as voice fingerprinting, wake-up spotters, and emergency sound detection, acoustic scene analysis, and listening target selection.

[0087] In the present disclosure, the electronic device (100) and the external device (200) can be functionally coupled and operate in processing of an audio signal. According to one or more embodiments of the present disclosure, the electronic device (100) and the external device (200) can perform operations for processing the audio signal separately. According to one or more embodiments of the present disclosure, the electronic device (100) and the external device (200) can perform different types of audio signal processing. For example, the electronic device (100) can perform processing that requires few computational resources, and the external device (200) can perform processing that requires many computational resources. For example, the electronic device (100) can perform real-time signal processing or signal processing that requires little latency, and the external device (200) can operate in a relatively long cycle or perform signal processing that does not require much latency.

[0088] In the present disclosure, the electronic device (100) can perform active noise removal using one or more filters.

[0089] FIG. 2 is a diagram for explaining the principle of noise canceling according to one embodiment of the present disclosure.

[0090] An electronic device (100) that performs noise cancellation may include one speaker and two microphones. For example, referring to FIG. 2, the electronic device may include a speaker that outputs sound Y(z) to the external auditory canal of a user wearing the electronic device (100), an external microphone that receives external sound K(z), and an internal microphone that receives external sound L(z) and sound inside the user's external auditory canal.

[0091] Here, the path for the sound of the electronic device (100) may include a primary path and an auxiliary path.

[0092] The fundamental path P(z) is the transmission path between the external microphone and the internal microphone, which represents how the external sound changes when it enters the ear, and can be expressed as P(z)=L(z) / K(z).

[0093] The auxiliary path S(z) is the transmission path between the speaker and the internal microphone, and can be expressed as S(z)Y(z) = D(z).

[0094] In a noise-canceling algorithm, the auxiliary path is measured upon booting of the electronic device (100) and simulated within the noise-canceling algorithm so that the response to a given output (S(z)) can be predicted. This allows for the use of an at least partially adaptive internal model control (IMC) approach in a real-time simulated acoustic system.

[0095] In the present disclosure, booting of an electronic device may mean the point in time when the electronic device is powered on or when the electronic device starts noise canceling.

[0096] Noise cancellation may include calculating the in-ear signal via D(z)=P(z)X(z) and calculating the speaker signal via Y(z)=D(z) / S(z). However, since S(z) has a longer delay time than P(z), Y(z) cannot be perfectly calculated. This limitation may also affect the convergence of the adaptive filter used for estimation.

[0097] To overcome these limitations, a noise removal system according to one or more embodiments of the present disclosure may generate a noise signal by combining various types of filter modules.

[0098] At this time, the performance of the noise removal system may vary depending on the length of the filter.

[0099] FIG. 3 is a diagram illustrating noise removal performance according to the length of a filter according to one embodiment of the present disclosure.

[0100] Specifically, referring to FIG. 3, when using a short filter (a short filter including 384 coefficients) or a long filter (a long filter including 1536 coefficients), noise is reduced compared to when the electronic device (100) is not worn, but when using a long filter, there is an advantage in that low-frequency noise can be effectively removed. However, a long filter has a disadvantage in that it requires a lot of computational resources due to the large amount of computational work. Conversely, a short filter has a disadvantage in that it cannot effectively remove low-frequency noise, but has an advantage in that it requires fewer computational resources.

[0101] The noise removal method according to the present disclosure can increase the consumption of computational resources while maintaining noise cancellation performance by compressing the filter.

[0102] The operation of the electronic device (100) according to the present disclosure to perform active noise cancellation will be described in detail with reference to the drawings below.

[0103] FIG. 4 is a block diagram illustrating a configuration of an electronic device (100) according to one or more embodiments of the present disclosure.

[0104] Referring to FIG. 4, the electronic device (100) may include at least one of a memory (110), a communication interface (120), a user interface (130), a microphone (140), a speaker (150), and one or more processors (160).

[0105] At least one of the above components may be omitted. For example, the electronic device (100) may include a memory (110), a microphone (140), a speaker (150), and one or more processors (160). Alternatively, the electronic device (100) may further include other components in addition to the above components.

[0106] The memory (110) can store at least one instruction regarding the electronic device (100). The memory (110) can store an operating system (O / S) for driving the electronic device (100). In addition, the memory (110) can store various software programs or applications for operating the electronic device (100) according to various embodiments of the present disclosure. In addition, the memory (110) can include a semiconductor memory such as a flash memory (110) or a magnetic storage medium such as a hard disk.

[0107] Specifically, the memory (110) can store various software modules for operating the electronic device (100) according to various embodiments of the present disclosure, and one or more processors (160) can control the operation of the electronic device (100) by executing various software modules stored in the memory (110). That is, the memory (110) is accessed by one or more processors (160), and data reading / recording / modifying / deleting / updating, etc. can be performed by the processors (160).

[0108] Meanwhile, in the present disclosure, the term memory (110) may be used to mean a memory (110), a ROM (not shown), a RAM (not shown) in a processor (160), or a memory card (not shown) (e.g., a micro SD card, a memory stick) mounted on an electronic device (100).

[0109] In the present disclosure, the memory (110) can store information about a filter for performing noise removal.

[0110] In the present disclosure, the memory (110) can store a buffer memory and a cache memory for performing a convolution operation between a filter and an audio sample.

[0111] The communication interface (120) includes circuitry and is a configuration capable of communicating with external devices and servers. The communication interface (120) can communicate with external devices or servers based on a wired or wireless communication method. The communication interface (120) may include a Bluetooth module (not shown), a Wi-Fi module (not shown), an IR (infrared) module, a LAN (Local Area Network) module, an Ethernet module, etc. Here, each communication module may be implemented in the form of at least one hardware chip. In addition to the above-described communication method, the wireless communication module may include at least one communication chip that performs communication according to various wireless communication standards such as Zigbee, USB (Universal Serial Bus), MIPI CSI (Mobile Industry Processor Interface Camera Serial Interface), 3G (3rd Generation), 3GPP (3rd Generation Partnership Project), LTE (Long Term Evolution), LTE-A (LTE Advanced), 4G (4th Generation), 5G (5th Generation), etc. However, this is only one embodiment, and the communication interface (120) can utilize at least one communication module among various communication modules.

[0112] According to one or more embodiments of the present disclosure, the communication interface (120) communicates with an external device (200) and can receive an audio signal for outputting sound.

[0113] According to one or more embodiments of the present disclosure, the communication interface (120) can receive user input to perform active noise cancellation from an external device (200).

[0114] The user interface (130) can acquire user input. The user interface (130) can be implemented as a device such as a button, a touch pad, a mouse, and a keyboard, or as a touch screen capable of performing the above-described display function and operation input function. Here, the button can be a mechanical button, a touch pad, a wheel, or various other types of buttons formed on any area of ​​the body exterior of the electronic device (100), such as the front, side, or back.

[0115] According to one or more embodiments of the present disclosure, the user interface (130) may obtain user input for selecting a noise removal operation mode, etc.

[0116] The microphone (140) is configured to acquire an audio signal. The microphone (140) may include an external microphone (141) and an internal microphone (142).

[0117] An external microphone (141) may be placed on the opposite side of the electronic device (100) worn by the wearer. The external microphone (141) may be a microphone for measuring a noise signal (external noise signal) to be removed. In the present disclosure, the external microphone (141) may be replaced with an expression representing an identical / similar concept, such as a "reference microphone."

[0118] The internal microphone (142) may be placed on the surface of the electronic device worn by the wearer. The internal microphone (142) may be a microphone for measuring the noise control result of the electronic device (100). That is, the internal microphone (142) may be positioned at a target point for noise control. The electronic device (100) according to the present disclosure may perform noise removal so that the noise measured through the internal microphone (142) converges to 0. In the present disclosure, the internal microphone (142) may be replaced with an expression representing the same / similar concept, such as an "error microphone."

[0119] The speaker (150) is configured to output an audio signal. In the present disclosure, the speaker (150) can remove or attenuate noise by outputting an anti-noise signal for removing a noise signal.

[0120] One or more processors (160) can control the overall operation and function of the electronic device (100). Specifically, one or more processors (160) are connected to a configuration of the electronic device (100) including a memory (110), and can control the overall operation of the electronic device (100) by executing at least one command stored in the memory (110) as described above.

[0121] The one or more processors (160) may be implemented in various ways. For example, the one or more processors (160) may be implemented as at least one of an application specific integrated circuit (ASIC), a logic integrated circuit, an embedded processor, a microcomputer (Micom), a microprocessor, hardware control logic, a hardware finite state machine (FSM), and a digital signal processor (160).

[0122] In particular, the one or more processors (160) may include one or more processors. Specifically, the one or more processors may include one or more of a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), an Accelerated Processing Unit (APU), a Many Integrated Core (MIC), a Digital Signal Processor (DSP), a Neural Processing Unit (NPU), a Main Processing Unit (MPU), a hardware accelerator, or a machine learning accelerator. The one or more processors may control one or any combination of other components of the electronic device, and may perform operations related to communication or data processing. The one or more processors may execute one or more programs or instructions stored in a memory. For example, the one or more processors may perform a method according to an embodiment of the present disclosure by executing one or more instructions stored in a memory.

[0123] When a method according to one or more embodiments of the present disclosure includes multiple operations, the multiple operations may be performed by one processor or by multiple processors. That is, when a first operation, a second operation, and a third operation are performed by a method according to one or more embodiments, the first operation, the second operation, and the third operation may all be performed by the first processor, or the first operation and the second operation may be performed by the first processor (160) and the third operation may be performed by the second processor (160).

[0124] One or more processors may be implemented as a single-core processor (160) including one core, or may be implemented as one or more multi-core processors (160) including multiple cores (e.g., homogeneous multi-cores or heterogeneous multi-cores). When one or more processors are implemented as a multi-core processor, each of the multiple cores included in the multi-core processor may include internal processor memory, such as cache memory or on-chip memory, and a common cache shared by the multiple cores may be included in the multi-core processor. In addition, each of the multiple cores (or some of the multiple cores) included in the multi-core processor may independently read and execute a program instruction for implementing a method according to one or more embodiments of the present disclosure, or all (or some) of the multiple cores may be linked to read and execute a program instruction for implementing a method according to one or more embodiments of the present disclosure.

[0125] When a method according to one or more embodiments of the present disclosure includes a plurality of operations, the plurality of operations may be performed by one core among the plurality of cores included in a multi-core processor, or may be performed by the plurality of cores. For example, when a first operation, a second operation, and a third operation are performed by a method according to one or more embodiments, the first operation, the second operation, and the third operation may all be performed by a first core included in the multi-core processor, or the first operation and the second operation may be performed by a first core included in the multi-core processor, and the third operation may be performed by a second core included in the multi-core processor.

[0126] According to one or more embodiments of the present disclosure, the one or more processors (160) may mean a system on a chip (SoC) in which one or more processors and other electronic components are integrated, a single core processor, a multi-core processor, or a core included in a single core processor or a multi-core processor, wherein the core may be implemented as a CPU, a GPU, an APU, a MIC, a DSP, an NPU, a hardware accelerator, or a machine learning accelerator, but embodiments of the present disclosure are not limited thereto.

[0127] The operation of one or more processors (160) to implement various embodiments of the present disclosure may be implemented through multiple modules.

[0128] Specifically, data for a plurality of modules according to the present disclosure can be stored in a memory (110), and one or more processors (160) can access the memory (110) to load the data for the plurality of modules into a memory or buffer within one or more processors (160), and then implement various embodiments according to the present disclosure using the plurality of modules.

[0129] However, at least one of the plurality of modules according to the present disclosure may be implemented in hardware and included in one or more processors (160) in the form of a system on chip.

[0130] Alternatively, at least one of the plurality of modules according to the present disclosure may be implemented as a separate external device, and the electronic device (100) and each module may communicate and perform operations according to the present disclosure.

[0131] Specifically, one or more processors (160) can control the overall operation of the electronic device (100) described below.

[0132] Hereinafter, the operation of the electronic device (100) according to the present disclosure will be described in detail with reference to the attached drawings.

[0133] FIG. 5 is a drawing for explaining the operation of a filter module according to an embodiment of the present disclosure.

[0134] Referring to FIG. 5, the memory (110) can store a filter module (111) including a filter (112).

[0135] An electronic device (100) can obtain a noise signal (20) through a microphone (140). The electronic device (100) can input the obtained noise signal (20) into a filter module (111). Then, the filter module (111) can obtain an anti-noise signal by passing the input noise signal through a filter (112) included in the filter module (111).

[0136] And, the electronic device (100) can output the acquired anti-noise signal (30) through a speaker (150).

[0137] According to one or more embodiments of the present disclosure, the filter module (111) can be implemented in various forms.

[0138] FIG. 6 is a drawing for explaining a filter module (111) according to an embodiment of the present disclosure.

[0139] The filter module (111) of the present disclosure can be implemented in a feed-forward structure.

[0140] Here, a feed-forward structure may mean a structure in which an input signal is processed by being transmitted forward in time, and the input of the filter does not depend on the previous output of the filter.

[0141] Specifically, referring to FIG. 6, the first filter module (111a) may include a filter (112a) and a filter adjustment module (113a). The filter (112a) may be an FIR filter configured to output an anti-noise signal when a noise signal acquired through an external microphone is input. The filter (112a) may perform an operation with audio samples constituting the noise signal to output the anti-noise signal.

[0142] The filter adjustment module (113a) can improve the performance of the filter by using input through the internal microphone (142). Specifically, the filter adjustment module (113a) can increase the noise removal efficiency of the filter (112a) by dynamically adjusting the coefficients of the filter (112a) by using a noise signal acquired through the internal microphone (142).

[0143] FIG. 7 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0144] The filter module of the present disclosure may be implemented with a feedback structure. In the present disclosure, the feedback structure may be replaced with a structure representing an identical / similar concept, such as feed-backward.

[0145] Here, a feedback structure may refer to a structure in which an input signal is input to a filter, processed, and then the output of the filter is input back into the filter. In other words, a feedback structure may refer to a structure in which the input of the filter depends on the previous output of the filter.

[0146] Specifically, referring to FIG. 7, the second filter module (111b) may include a filter (112b), a filter adjustment module (113b), and a feedback (114b) module.

[0147] Since the filter and filter adjustment module have been described through Fig. 7, redundant descriptions are omitted.

[0148] Referring again to FIG. 7, the filter (111b) may be an FIR filter configured to output an anti-noise signal when a noise signal acquired through the internal microphone (142) is input. That is, the filter (111b) illustrated in FIG. 5 is a filter configured to remove noise measured through the internal microphone (142).

[0149] The feedback module (114b) is a module for compensating for the influence of a signal output through the filter (111b) being re-input to the internal microphone (142). That is, a noise signal acquired through the internal microphone (142) is corrected by the feedback module (114b), and the corrected audio signal can be input to the filter (112b).

[0150] FIG. 8 is a drawing for explaining a filter module according to an embodiment of the present disclosure.

[0151] The filter module (111) of the present disclosure can be implemented with a structure including a filter module implemented with a feed-forward structure and a filter module implemented with a feedback structure.

[0152] Specifically, referring to FIG. 8, the filter module (111) may include a first filter module (111a) and a second filter module (111b). The first filter module (111a) has been described with reference to FIG. 4, and the second filter module (111b) has been described with reference to FIG. 5, so redundant descriptions will be omitted.

[0153] The electronic device (100) can generate an anti-noise signal by adding a signal output through a filter (112a) of a first filter module (111a) and a signal output through a filter (112b) of a second filter module (111b). In addition, the electronic device (100) can output the generated anti-noise signal through a speaker.

[0154] Meanwhile, the filter module illustrated in FIG. 8 in the present disclosure may be referred to as an “adaptive hybrid ANC module.”

[0155] FIG. 9 is a drawing illustrating a filter module according to one or more embodiments of the present disclosure.

[0156] The filter module (111) of the present disclosure can be implemented with a structure including an adaptive hybrid ANC module and a filter module of a fixed feedback structure.

[0157] Here, the fixed feedback structure may mean a structure in which the filter adjustment module that dynamically adjusts the coefficients of the filter is excluded from the filter of the feedback structure described through FIG. 7.

[0158] That is, a fixed feedback structure can filter an input signal based on fixed coefficients. Furthermore, the input of a fixed feedback filter can be a structure that depends on the previous output of the fixed feedback filter.

[0159] Referring to FIG. 9, the filter module (111) may include a first filter module (111a), a second filter module (111b), and a third filter module (111c). The first filter module (111a) has been described with reference to FIGS. 4 and 6, and the second filter module (111b) has been described with reference to FIGS. 5 and 6, so redundant descriptions will be omitted.

[0160] At this time, the third filter module (111c) may be implemented with a fixed feedback structure. Specifically, the third filter module (111c) may include a filter (112c) and a feedback module (113c).

[0161] At this time, the filter (112c) may be a fixed IIR filter. A fixed IIR filter has fixed coefficients, which allows for consistency in signal processing. Furthermore, a fixed IIR filter can provide low delay time and high signal processing efficiency.

[0162] The electronic device (100) can obtain an internal noise signal through an internal microphone (142). Then, the electronic device (100) can input the internal noise signal to a filter (112c).

[0163] The electronic device (100) can exclude the signal output from the filter (112c) from the signal input to the first filter module (111a) and the second filter module (111b) through the feedback module (113c).

[0164] Meanwhile, the combination of the filter modules (111) described above is only one embodiment, and the filter modules (111) of the present disclosure can be combined in various forms.

[0165] For example, the filter module (111) may include only the third filter module (111c). Alternatively, the filter module (111) may include only the first filter module (111a) and the third filter module (111c). Alternatively, the filter module (111) may include only the second filter module (111b) and the third filter module (111c).

[0166] FIG. 10 is a drawing for explaining the operation of a plurality of modules according to an embodiment of the present disclosure.

[0167] Referring to FIG. 10, the memory (110) may include an auxiliary path acquisition module (1010), a third filter personalization module (1020), a third filter module (1030), an adaptive hybrid ANC module (1040), an IMC decoupling module (1050), and a noise removal module (1060).

[0168] When the electronic device boots up, the auxiliary path acquisition module (1010) can acquire an auxiliary path. Specifically, the auxiliary path acquisition module (1010) can acquire an auxiliary path S(z), which is a transmission path between the speaker (150) and the internal microphone (142), through an audio signal acquired through the output of the speaker (150) and the internal microphone (142).

[0169] Here, booting of the electronic device (100) may mean the point in time when the electronic device is powered on or when the electronic device (100) begins to start noise canceling.

[0170] The third filter personalization module (1020) can obtain a personalized third filter using an auxiliary path. Specifically, the third filter personalization module (1020) can determine the coefficient of the third filter using an auxiliary path. That is, the auxiliary path can be obtained differently depending on the shape of the individual's external auditory canal, etc., and the third filter personalization module (1020) can determine the coefficient of the third filter module (1030) using the auxiliary path obtained according to the shape of the user's external auditory canal, thereby personalizing the third filter module (1030).

[0171] Accordingly, the personalized third filter module (1030) can provide an optimized noise removal environment to the user.

[0172] The adaptive hybrid filter module (1040) has been described with reference to FIG. 8, so any duplicate description is omitted.

[0173] In order to reduce the booting delay of the electronic device (100) according to the present disclosure, the electronic device (100) can start noise removal through the adaptive hybrid filter module (1040) while the third filter personalization module (1020) personalizes the third filter module (1030).

[0174] The IMC decoupling module (1050) is a module for minimizing the interdependence between the feed forward filter module and the feedback filter module in the adaptive hybrid filter module (1040).

[0175] When a personalized third filter module (1030) is obtained by the third filter personalization module (1020), the electronic device (100) can perform noise removal by combining the adaptive hybrid filter module (1040) and the third filter module.

[0176] The filter module combining the adaptive hybrid filter module (1040) and the third filter module (1030) has been described with reference to FIG. 9, so a duplicate description will be omitted.

[0177] The noise removal module (1060) can perform noise removal using data output from the adaptive hybrid filter module (1040) and the third filter module (1030).

[0178] Meanwhile, although not shown in the drawing, the operation of the third filter personalization module (1020) may be omitted. That is, information about the third filter may be pre-stored in the memory (110), and the electronic device (100) may perform a noise removal operation using the third filter pre-stored in the memory (110).

[0179] According to one or more embodiments of the present disclosure, the filter may be a coefficient-compressed filter. For example, the filters included in the first filter module and the second filter module illustrated in FIG. 6 may be compressed filters.

[0180] The electronic device (100) of the present disclosure can compress the filter differently for each of a plurality of stages.

[0181] FIG. 11 is a diagram illustrating a method for an electronic device according to an embodiment of the present disclosure to compress a filter. Here, the filter to be compressed may be, but is not limited to, an FIR filter.

[0182] The memory (110) can store information about the uncompressed original filter.

[0183] The electronic device (100) can divide the original filter into multiple stages and compress each of the multiple stages to a different level. In this case, the larger the stage, the greater the compression level. This is because the earlier the response in the filter, the more important it is and the greater the impact it has on the input signal.

[0184] Specifically, the electronic device (100) can divide the filter into multiple stages based on the input order of the coefficients. Here, the input order may refer to the order in which the coefficients of the filter are applied to the input signal. In other words, the electronic device (100) can divide the original filter into multiple sections based on the degree of delay of the input processed by the coefficients constituting the filter.

[0185] For example, the electronic device (100) inputs the original filter in the order of 2 k1 The first stage (1111) including coefficients less than or equal to the second, the input order is 2 k1 Exceeds the second and k2 The second stage (1112) including coefficients less than or equal to the second, the input order being 2 k2 Exceeds the second and the input sequence is 2 k3 It can be divided into a third stage (1113) including coefficients less than the second. In the present disclosure, k can mean any natural number. Meanwhile, the number and length of the stages are not limited thereto and can be implemented in various forms.

[0186] In addition, the electronic device (100) can compress each of the plurality of stages to a compression level corresponding to each of the plurality of stages. At this time, the electronic device (100) can compress each of the plurality of stages so that each of the plurality of stages includes the same number of coefficients. In other words, the electronic device (100) can compress each stage to a higher compression level as the number of coefficients included in the stage increases.

[0187] Specifically, stages containing coefficients with early input order can be uncompressed or compressed to a low level. Furthermore, stages containing high coefficients with late input order can be compressed to a high level. In other words, stages with lower input delay can be uncompressed or compressed to a low level. In other words, stages with greater input delay can be compressed to a high level.

[0188] For example, the electronic device (100) may not compress the first stage (1111). And, the electronic device (100) may compress the second stage (1112) to the first compression level. At this time, the electronic device (100) may compress the second stage (1112) so that the number of coefficients is 2 of the original coefficients. -1 This allows the coefficients included in the second stage to be compressed.

[0189] And, the electronic device (100) can compress the third stage (1113) to a second compression level that is greater than the first compression level. At this time, the electronic device (100) can compress the third stage (1113) to a second compression level that is greater than the first compression level. -2 This can be compressed to make it so.

[0190] For example, referring to FIG. 11, the electronic device may not compress four coefficients belonging to the first stage (1111). In addition, the electronic device may compress eight coefficients belonging to the second stage (1112) into four coefficients. In addition, the electronic device may compress 16 coefficients belonging to the third stage (1113) into four coefficients.

[0191] Accordingly, adjacent audio samples input to each stage can be operated on by the same coefficients.

[0192] Meanwhile, the electronic device (100) according to the present disclosure can compress the filter as described above, but this is only one embodiment, and the electronic device (100) may pre-store information about the compressed filter in the memory (110).

[0193] Additionally, the electronic device may perform a noise removal operation by loading a pre-compressed filter stored in the memory (110).

[0194] An electronic device (100) according to the present disclosure can input a plurality of audio samples into one of a plurality of stages.

[0195] Referring to FIG. 11, the electronic device (100) can perform a convolution operation on audio samples constituting a noise signal with each of the first stage (1111), the second stage (1112), and the third stage (1113) of the filter in time sequence.

[0196] At this time, the electronic device (100) can input a first audio sample group (1121) including the most recently input audio sample into the first stage (1111).

[0197] Specifically, the electronic device (100) can input a first audio sample group (1121) among audio samples constituting a noise signal to a first stage (1111) of a filter. That is, the electronic device (100) can perform a convolution operation between the first audio sample group (1121) and coefficients of a filter constituting the first stage. At this time, the electronic device (100) can input the first audio sample group (1121) to the first stage (1111) at a first sampling rate.

[0198] And, the electronic device (100) can input a second audio sample group (1122) among the audio samples constituting the noise signal to the second stage (1112) of the filter. That is, the electronic device (100) can perform a convolution operation between the second audio sample group (1122) and the coefficients of the filter constituting the second stage (1112). At this time, the electronic device (100) can input the second audio sample group (1122) to the second stage (1112) at a second sampling rate lower than the first sampling rate.

[0199] For example, the electronic device (100) can input a signal obtained by downsampling the second audio sample group (1122) by 1 / 2 from the first sampling rate to the second stage (1112).

[0200] And, the electronic device (100) can input a third audio sample group (1123) among the audio samples to the third stage (1113) of the filter. That is, the electronic device (100) can perform a convolution operation between the coefficients of the filter constituting the third audio sample group (1123) and the third stage (1113). At this time, the electronic device (100) can input the third audio sample group (1123) to the third stage (1113) at a third sampling rate lower than the second sampling rate.

[0201] For example, the electronic device (100) can input a signal down-sampled by 1 / 2 from the second sampling rate (i.e., a signal down-sampled by 1 / 4 from the first sampling rate) of the third audio sample group (1123) to the third stage (1113).

[0202] A method for an electronic device (100) to input multiple audio sample groups into each of multiple stages at different sampling rates will be described with reference to FIG. 12 below.

[0203] FIG. 12 is a diagram for explaining a method for an electronic device (100) according to an embodiment of the present disclosure to input an audio sample into a filter.

[0204] Referring to FIG. 12, the electronic device (100) can input k audio samples in a recently acquired order from audio samples (1210) to the first stage (1111) of the filter. At this time, the electronic device (100) can input k audio samples recently acquired at a first sampling rate to the first stage (1111).

[0205] At this time, the first sampling rate may be the same as the sampling rate at which the audio sample was acquired, but is not limited thereto, and the electronic device (100) may downsample the audio sample to the first sampling rate and input the downsampled audio sample to the first stage (1111).

[0206] The electronic device (100) can input audio samples constituting a noise signal, in a number of audio samples equal to the number of coefficients (k) of the first stage, starting from the most recent order, into the first stage (1111). That is, the electronic device (100) can perform a convolution operation between the obtained k audio samples and the coefficients of the first stage (1111) of the filter.

[0207] In addition, the electronic device (100) can delay k samples from the audio sample (S1210) and downsample subsequent audio samples by half (S1220). That is, the electronic device (100) can downsample the remaining audio samples except for the audio samples input to the first stage (1110) from the audio sample (1210) by half.

[0208] And, the electronic device (100) can input k audio samples among the downsampled audio samples to the second stage (1112). That is, the electronic device (100) can perform a convolution operation between the obtained k audio samples and the coefficients of the second stage (1112) of the filter.

[0209] Thereafter, the electronic device (100) can delay k samples from the audio sample again (S1230) and downsample the subsequent audio sample by half (S1240). Then, the electronic device (100) can input k audio samples from the downsampled audio samples to the third stage (1112) of the filter. That is, the electronic device (100) can perform a convolution operation between the obtained k audio samples and the coefficients of the third stage (1112) of the filter.

[0210] And, the electronic device (100) can obtain a filtered audio sample (1220) by adding data output from each stage of the filter.

[0211] Additionally, the electronic device (100) can generate anti-noise using the filtered audio sample (1220).

[0212] A more detailed method of downsampling audio samples by an electronic device (100) and inputting the downsampled audio samples into each stage of a filter will be described with reference to FIGS. 13 to 16 below.

[0213] FIGS. 13, 14, 15 and 16 are diagrams illustrating how an electronic device downsamples audio samples and inputs the downsampled audio samples to each stage of a filter according to various embodiments of the present disclosure.

[0214] Referring to FIG. 13, the electronic device (100) can store audio samples constituting a noise signal in a buffer memory (110). Specifically, the electronic device (100) can store audio samples for performing operations with each stage of the filter in the buffer memory.

[0215] Meanwhile, in the present disclosure, the buffer memory in which audio samples are stored may mean a buffer memory within one or more processors (160), but this is only one embodiment, and the buffer memory in which audio samples are stored may mean a buffer memory within the memory (110).

[0216] Specifically, the electronic device (100) can store audio samples in a buffer within one or more processors (160). At this time, the buffer memory in which the audio samples are stored can be divided into a plurality of areas (1311, 1312, 1313, 1314) corresponding to a plurality of stages included in the filter. In other words, if the filter includes k stages, the buffer in which the audio samples are stored can be divided into k areas.

[0217] At this time, each area of ​​the buffer memory (110) where audio samples are stored can store a number of audio samples corresponding to the number of weights per stage of the filter. In other words, if the number of weights per stage of the filter is k, the number of audio samples stored in one buffer memory area can be k.

[0218] And, the electronic device (100) can perform an operation between the audio sample stored in the kth buffer memory area and the kth stage of the filter.

[0219] As audio samples are continuously acquired, newly acquired audio samples (1301) can be input into a buffer memory area. Then, the electronic device (100) can perform operations using the buffer into which new audio samples are input.

[0220] Specifically, when a new audio sample (1301) is acquired, the electronic device (100) can input the acquired audio sample (1301) into the first buffer memory area (1311).

[0221] Accordingly, referring to FIG. 14, the electronic device (100) may move the oldest audio sample (1303) among the audio samples stored in the first buffer memory area (1311) from the first buffer memory area (1311) to the first cache memory area (1321). That is, the electronic device (100) may remove the oldest audio sample (1303) from the first buffer memory area (1311) and store the audio sample removed from the first buffer memory area (1311) in the first cache memory area (1321). In the present disclosure, the cache memory area (1360) may mean a memory space for storing audio samples for downsampling. At this time, the number of cache memory areas may be equal to the number of buffer memory areas. Audio samples removed from the k buffer memory area (1311, 1312, 1313) can be moved to the k cache memory area (1321, 1322, 1323).

[0222] Meanwhile, in the present disclosure, the cache memory (1320) in which audio samples are stored may refer to a cache memory (1320) within one or more processors (160), but this is only one embodiment, and the buffer memory in which audio samples are stored may refer to a buffer memory within the memory (110).

[0223] In the present disclosure, “buffer memory” or “cache memory” may be replaced with expressions indicating the same / similar concept, such as “memory within one or more processors (160)” or “memory (110).”

[0224] In the present disclosure, the “region” of the buffer memory or the “region” of the cache memory may be replaced with an expression representing the same / similar concept, such as “group” or “portion”.

[0225] After the audio sample (1303) is moved from the first buffer memory area (1311) to the first cache memory area (1321), referring to FIG. 15, if a new audio sample (1302) is additionally input into the first buffer memory area (1311), the electronic device (100) can move the oldest audio sample (1304) in the first buffer memory area (1311) to the first cache memory area (1321).

[0226] Hereafter, referring to FIG. 16, when two audio samples (1303, 1304) are stored in the first cache memory area (1321), the electronic device (100) can down-sample the two audio samples (1303, 1304) into one audio sample (1305). At this time, the electronic device (100) can perform down-sampling using an average value of the bit values ​​of the two audio samples (1303, 1304), but is not limited thereto. At this time, the bit value of the down-sampled one audio sample (1305) can be an average value of the bit values ​​of the two audio samples (1303, 1304). According to one or more embodiments of the present disclosure, the electronic device (100) can also perform down-sampling by selecting one audio sample among the two audio samples or using a higher value among the two audio samples.

[0227] And, when a down-sampled audio sample (1305) is generated from two audio samples stored in the first cache memory area (1321), the electronic device (100) can remove the audio samples (1321, 1322) stored in the first cache memory area (1321).

[0228] And, the electronic device (100) can input one down-sampled audio sample (1305) into the second buffer memory area (1312). When the audio sample (1305) is input into the second buffer memory area (1312), the electronic device (100) can perform a convolution operation between the audio sample stored in the second buffer memory area (1312) and the weight of the filter.

[0229] As described with reference to the first buffer memory area (1311), when one audio sample (1305) is input into the second buffer memory area (1312), the electronic device (100) can move the oldest audio sample among the audio samples stored in the second buffer memory area (1312) from the second buffer memory area (1312) to the second cache memory area (1322). That is, the electronic device (100) can remove the oldest audio sample from the second buffer memory area (1312) and store the audio sample removed from the second buffer memory area (1312) in the second cache memory area (1322).

[0230] In this way, when two audio samples are input into the second buffer memory area (1312), the two audio samples can be stored in the second cache memory area (1322).

[0231] When two audio samples are stored in the second cache memory area (1322), the electronic device (100) can downsample the two audio samples stored in the second cache memory area (1322) into one audio sample. At this time, the method by which the electronic device (100) downsamples may be the same as the method described above.

[0232] And, the electronic device (100) can input one down-sampled audio sample into the third buffer memory area (1313). In other words, if four audio samples are input into the first buffer memory area (1311), one audio sample can be input into the third buffer memory area (1313).

[0233] As described above, as audio samples are acquired, audio samples may be added to at least one buffer memory area. When audio samples are added to a buffer memory area, the electronic device (100) may input the audio samples contained in the buffer memory area to which the audio samples are added to a filter stage corresponding to the buffer memory area.

[0234] Therefore, the first stage of the filter can perform one operation each time an audio sample is acquired. And, 2 1 The second stage of the filter can perform one operation each time an audio sample is acquired. And, 2 2 The third stage of the filter can perform one operation each time an audio sample is acquired. Similarly, 2 3 Each time an audio sample is acquired, the fourth stage of the filter can perform one operation.

[0235] Accordingly, the electronic device (100) according to the present disclosure can have a preset number of stages (e.g., up to two) perform calculations among a plurality of stages each time an audio sample is acquired. That is, since not all filter stages perform calculations each time an audio sample is acquired, the consumption of computational resources can be effectively reduced.

[0236] FIG. 17 and FIG. 18 are graphs showing noise performance according to combinations of filter modules according to various embodiments of the present disclosure.

[0237] Referring to FIGS. 17 and 18, noise can be effectively removed when the first filter, the second filter, and the third filter are used together (Type 3) rather than when only the third filter of the present disclosure is used alone (Type 1) or when only the first and second filters are used alone (Type 2).

[0238] Referring to Fig. 18, a combination of filter modules according to Type 3 shows a higher attenuation value than a combination of filter modules according to Type 1 or Type 2.

[0239] FIGS. 19 and 20 are graphs showing noise performance according to the degree of compression of a filter module according to one or more embodiments of the present disclosure.

[0240] Referring to FIGS. 19 and 20, the noise removal performance of the filter in the present disclosure, in which the number of stages that do not perform filter compression is 1, and the filters in which the number of stages that perform filter compression are 4 and 6, can both effectively remove noise.

[0241] At this time, as illustrated in FIG. 20, the number of taps of the filter that performed filter compression is smaller than the number of taps of the filter that did not perform compression. Therefore, compared to a filter with one stage, a filter with six stages has the effect of reducing computational consumption by approximately 1 / 30. In other words, the noise removal method according to the present disclosure has the effect of effectively removing noise while efficiently reducing computational resources.

[0242] FIG. 21 is a drawing for explaining a control method of an electronic device according to an embodiment of the present disclosure.

[0243] Referring to FIG. 21, the electronic device (100) can obtain a noise signal (S2110). The electronic device (100) can obtain the noise signal through at least one microphone included in the electronic device (100).

[0244] An electronic device (100) according to the present disclosure can input a plurality of audio samples constituting a noise signal into a filter including a plurality of stages (S2120). At this time, the electronic device (100) can input the plurality of audio samples into each of the plurality of stages at different sampling rates.

[0245] Meanwhile, a filter comprising multiple stages may be a filter in which the original filter is compressed to a different level in each of the multiple stages. Furthermore, each of the multiple stages may be a compressed filter that includes the same number of coefficients.

[0246] The electronic device (100) can input the same number of audio samples to each of the multiple stages.

[0247] Meanwhile, the electronic device (100) can downsample adjacent audio samples into one audio sample and input the downsampled audio sample into one of the multiple stages.

[0248] Meanwhile, the filter according to the present disclosure may include a first filter configured to filter an external noise signal acquired through an external microphone, a second filter configured to generate a first feedback signal from an internal noise signal acquired through an internal microphone and having a coefficient dynamically adjusted, and a third filter configured to generate a second feedback signal from an internal noise signal acquired through an internal microphone and having a fixed coefficient.

[0249] An electronic device (100) according to the present disclosure can generate an anti-noise signal for attenuating a noise signal using data output from a plurality of stages (S2130).

[0250] Although various embodiments have been described above, each embodiment is not necessarily implemented individually, and may be implemented together in a single product by being combined in whole or in part with at least one other embodiment.

[0251] Meanwhile, the terms "part" or "module" used in the present disclosure include units composed of hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A "part" or "module" may be an integrally composed component, a minimum unit performing one or more functions, or a portion thereof. For example, a module may be composed of an application-specific integrated circuit (ASIC).

[0252] Various embodiments of the present disclosure may be implemented as software including instructions stored in a machine-readable storage medium that can be read by a machine (e.g., a computer). The device, which is a device capable of calling instructions stored in the storage medium and operating according to the called instructions, may include an electronic device (100) according to the disclosed embodiments. When the instructions are executed by a processor, the processor may directly or under the control of the processor perform a function corresponding to the instructions using other components. The instructions may include code generated or executed by a compiler or interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, "non-transitory" means that the storage medium does not contain signals and is tangible, but does not distinguish between data being stored semi-permanently or temporarily in the storage medium.

[0253] According to one or more embodiments, the methods according to the various embodiments disclosed herein may be provided as a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)) or online through an application store (e.g., Play Store™). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0254] Each component (e.g., a module or a program) according to various embodiments may be composed of one or more entities, and some of the aforementioned sub-components may be omitted, or other sub-components may be further included in various embodiments. Alternatively or additionally, some components (e.g., a module or a program) may be integrated into a single entity, which may perform the same or similar functions as those performed by each of the respective components prior to integration. Operations performed by a module, program, or other component according to various embodiments may be executed sequentially, in parallel, iteratively, or heuristically, or at least some operations may be executed in a different order, omitted, or other operations may be added.

[0255] The various embodiments of the present disclosure described in the claims and specification may be implemented in hardware, software, or a combination of hardware and software.

[0256] Such software may be stored on a nonvolatile computer-readable storage medium. The nonvolatile computer-readable storage medium stores one or more computer programs (software modules), which, when individually or collectively executed by one or more processors of an electronic device, may include computer-executable instructions that cause the electronic device to perform the methods of the present disclosure.

[0257] Such software may be stored in the form of a storage device, such as, for example, read-only memory (ROM), whether or not the device is erasable or rewritable, or in the form of, for example, random access memory (RAM), a memory chip, a device, or an integrated circuit. Furthermore, the software may be stored in the form of an optically or magnetically readable medium, such as, for example, a compact disc (CD), a digital video disc (DVD), a magnetic disk, or a magnetic tape. It will be appreciated that the storage device and the storage medium are various embodiments of non-volatile machine-readable storage media suitable for storing a computer program or computer programs including instructions. Accordingly, various embodiments may provide a program including code for implementing an apparatus or method as claimed in any of the claims of the present specification, and a non-volatile machine-readable storage medium storing such a program.

[0258] While the present disclosure has been described and shown with reference to various embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method for controlling an electronic device for active noise cancellation, Step of acquiring a noise signal; A step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages; and A control method comprising: a step of generating an anti-noise signal for attenuating the noise signal by using data output from the plurality of stages.

2. In paragraph 1, The step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages is: A control method for inputting the plurality of audio samples into each of the plurality of stages at different sampling rates.

3. In paragraph 1, The above control method is, A control method further comprising the step of compressing the original filter to a different level in each of the plurality of stages.

4. In paragraph 1, A control method, wherein each of the above plurality of stages includes the same number of coefficients.

5. In paragraph 1, The step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages is: A control method for inputting the same number of audio samples into each of the above plurality of stages.

6. In paragraph 1, The step of inputting a plurality of audio samples constituting the above noise signal into a filter divided into a plurality of stages is: Downsample adjacent audio samples into a single audio sample, A control method for inputting a single downsampled audio sample into one of the plurality of stages.

7. In paragraph 1, The above filter comprises a first stage and a second stage, The step of inputting a plurality of audio samples constituting the above noise signal into a filter divided into a plurality of stages is: Input two audio samples into the first buffer memory corresponding to the first stage, When the above two audio samples are input into the first buffer memory, the two audio samples in the oldest order among the audio samples stored in the first buffer memory are down-sampled into one audio sample, A control method for inputting the downsampled single audio sample into a second buffer memory corresponding to the second stage.

8. In paragraph 7, The above control method is, A control method further comprising the step of inputting a plurality of audio samples stored in the first buffer memory into a first stage of the filter.

9. In paragraph 1, The above filter is, A first filter configured to filter an external noise signal acquired through an external microphone; A first feedback signal is generated from an internal noise signal acquired through an internal microphone, and a second filter whose coefficient is dynamically adjusted; and A control method comprising: generating a second feedback signal from the internal noise signal acquired through the internal microphone; and further including a third filter with a fixed coefficient.

10. In paragraph 9, The third filter above is, A control method further comprising a feedback module for excluding the output of the third filter from the internal noise signal acquired through the internal microphone.

11. In paragraph 9, The above control method is, A step of identifying the path by which sound output from the speaker reaches the internal microphone located inside the electronic device; and A control method further comprising: a step of determining a coefficient of the third filter using the identified path.

12. In paragraph 11, The step of inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages is: A control method wherein the noise signal is input to the first filter and the second filter while determining the coefficients of the second feedback filter.

13. In an electronic device performing active noise cancellation, At least one microphone; speaker; A memory storing one or more computer programs; and a processor collectively connected to at least one microphone, the speaker and the memory; The one or more computer programs, when individually or collectively executed by the one or more processors, cause the electronic device to: To obtain a noise signal through at least one microphone, Inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages, An electronic device that controls the speaker to output an anti-noise signal for attenuating the noise signal by using data output from the plurality of stages.

14. In paragraph 13, The one or more computer programs, when individually or collectively executed by the one or more processors, cause the electronic device to: An electronic device that inputs the plurality of audio samples to each of the plurality of stages at different sampling rates.

15. One or more nonvolatile computer-readable storage media, The storage medium stores one or more computer programs, wherein the computer programs include computer execution instructions, When the above computer execution instructions are individually or collectively executed by one or more processors of the electronic device, the electronic device, Acquire the noise signal, Inputting a plurality of audio samples constituting the above noise signal into a filter including a plurality of stages, A computer-readable storage medium that generates an anti-noise signal for attenuating the noise signal by using data output from the plurality of stages.

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