Apparatus and method for sensor-based control of audio signals

Abstract

An audio device according to an embodiment may include at least one processor, at least one speaker, at least one microphone, a filter circuit, and at least one sensor. The at least one processor may output a first audio signal through the at least one speaker. The at least one processor may receive a noise signal through the at least one microphone. The at least one processor may generate a tuning signal based on the noise signal. The at least one processor may output a second audio signal through the at least one speaker, the second audio signal having the generated tuning signal and the first audio signal combined with each other. The at least one processor may detect an external input through the at least one sensor. The at least one processor may vary a gain of the filter circuit in response to an external input.

Description

Technical Field

[0001] The following description relates to apparatus and methods for sensor-based control of audio signals. Background Art

[0002] In order to output the sound signal, an audio device (e.g., earplugs) may be used. In order to remove the ambient noise while outputting the sound signal, the audio device may perform a noise cancellation (e.g., active noise cancellation (ANC)) function through a microphone and a speaker. In addition, in order to more accurately obtain the ambient sound, the audio device may perform an ambient sound enabling function or a personal sound amplification product (PSAP) function for hearing the ambient sound by using a microphone.

[0003] The above information may be provided as prior art to assist in understanding the present disclosure. No claim or determination is made as to whether any of the above information may be applied as prior art related to the present disclosure. Summary of the invention

[0004] According to an embodiment, the audio device may include at least one processor, at least one speaker, at least one microphone, a filter circuit and at least one sensor. At least one processor may be configured to output a first audio signal through at least one speaker. At least one processor may be configured to receive a noise signal through at least one microphone. At least one processor may be configured to generate a tuning signal based on the noise signal. At least one processor may be configured to output a second audio signal through at least one speaker, in which the generated tuning signal and the first audio signal are combined. At least one processor may be configured to detect an external input through at least one sensor. At least one processor may be configured to change the gain of the filter circuit in response to the external input. At least one processor may be configured to pass the second audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. At least one processor may be configured to output an output signal through at least one speaker.

[0005] According to an embodiment, the audio device may include at least one processor, at least one speaker, at least one microphone, a filter circuit and at least one sensor. At least one processor may be configured to receive an external signal through at least one microphone. At least one processor may be configured to generate a tuning signal based on the external signal. At least one processor may be configured to output the generated tuning signal through at least one speaker. At least one processor may be configured to detect an external input through at least one sensor. At least one processor may be configured to change the gain of the filter circuit in response to the external input. At least one processor may be configured to pass an audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. At least one processor may be configured to output an output signal through at least one speaker.

[0006] According to an embodiment, the method performed by the audio device may include outputting a first audio signal through at least one speaker. The method may include receiving a noise signal through at least one microphone. The method may include generating a tuning signal based on the noise signal. The method may include outputting a second audio signal through at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal. The method may include detecting an external input through at least one sensor. The method may include changing the gain of a filter circuit in response to the external input. The method may include passing a second audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. The method may include outputting the output signal through at least one speaker.

[0007] According to an embodiment, a non-transitory computer-readable medium is provided. When the non-transitory computer-readable medium is executed by one or more processors, program instructions may be provided, which perform the following functions: output a first audio signal through at least one speaker, receive a noise signal through at least one microphone, generate a tuning signal based on the noise signal, output a second audio signal through at least one speaker, the second audio signal is a combination of the generated tuning signal and the first audio signal, detect an external input through at least one sensor, and change the gain of a filter circuit in response to the external input; pass the second audio signal received through at least one microphone through the filter circuit whose gain has been changed to generate an output signal; and output the output signal through the at least one speaker.

[0008] According to an embodiment, when a non-transitory computer-readable medium is executed by one or more processors, it may be provided with program instructions that perform the following functions: receive an external signal through at least one microphone, generate a tuning signal based on the external signal, output a second audio signal through at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal, detect an external input through at least one sensor, change the gain of a filter circuit in response to the external input, pass the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to generate an output signal, and output the output signal through at least one speaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 An example of a state in which an audio device according to an embodiment is close to a user's body is shown.

[0010] Figure 2 An example of a state in which an audio device according to an embodiment is connected to a power supply device is shown.

[0011] Figure 3 is a block diagram illustrating components of an audio device according to an embodiment.

[0012] Figure 4 An example of a wearable audio device according to an embodiment is shown.

[0013] Figure 5 An example of movement of an audio device according to an embodiment is shown.

[0014] Figure 6a An example of the signal inflow characteristics through the secondary path according to the blocking amount of the speaker port is shown.

[0015] Figure 6b An example of signal inflow characteristics according to the volume of the external auditory canal is shown.

[0016] Figure 7 A functional configuration of an audio device according to an embodiment is shown.

[0017] Figure 8a An example of a functional configuration of an audio device including a filter circuit combination unit according to an embodiment is shown.

[0018] Figure 8b An example of a functional configuration of an audio device including a portion of a filter circuit according to an embodiment is shown.

[0019] Figure 8c An example of a functional configuration of an audio device including a filter circuit combination unit according to an embodiment is shown.

[0020] Fig. 9 An example of a functional configuration of an audio device for controlling filter characteristics without a microphone according to an embodiment is shown.

[0021] Fig.10 is a flowchart for illustrating an operation of an audio device for controlling an audio signal when active noise cancellation (ANC) is performed according to an embodiment.

[0022] Fig.11 is a flowchart for illustrating an operation of an audio device for controlling an audio signal when an ambient sound enabling function or a personal sound amplification product (PSAP) function for hearing ambient sounds is performed according to an embodiment. DETAILED DESCRIPTION

[0023] The terms used in the present disclosure are only used to describe specific embodiments, and may not be intended to limit the scope of another embodiment. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. The terms used herein (including technical terms or scientific terms) may have the same meaning as the meanings generally understood by those of ordinary skill in the art described in the present disclosure. Among the terms used in the present disclosure, the terms defined in the general dictionary may be interpreted as the same or similar meanings as the contextual meanings of the relevant technology, and unless clearly defined in the present disclosure, are not interpreted as ideal or overly formal meanings. In some cases, even the terms defined in the present disclosure may not be interpreted as excluding embodiments of the present disclosure.

[0024] In various embodiments of the present disclosure described below, a hardware method will be described as an example. However, since various embodiments of the present disclosure include techniques using both hardware and software, various embodiments of the present disclosure do not exclude a software-based method.

[0025] For ease of explanation, terms related to feedback microphones (e.g., feedback microphones, error microphones, first microphones), terms related to reference microphones (e.g., reference microphones, feedforward microphones, second microphones), and terms related to audio equipment (e.g., audio devices, audio output equipment, true wireless stereo headphones) used in the following description are exemplified. Therefore, the present disclosure is not limited to the terms to be described below, and another term with an equivalent technical meaning may be used. In addition, terms such as "...unit", "...device", "...material", and "...structure" used below may mean at least one shape structure or may mean a unit of a processing function.

[0026] In addition, in the present disclosure, the term "greater than" or "less than" can be used to determine whether a specific condition is met or achieved, but this is merely a description of an example, and does not exclude the description of "greater than or equal to" or "less than or equal to". The case described as "greater than or equal to" can be replaced by "greater than", the case described as "less than or equal to" can be replaced by "less than", and the case described as "greater than or equal to and less than" can be replaced by "greater than and less than or equal to". In addition, hereinafter, "A to B" refers to at least one of the elements from A (including A) to B (including B). hereinafter, "C" and / or "D" refers to at least one of "C" or "D", that is, {"C", "D" and "C" and "D"}.

[0027] Before describing the embodiments of the present disclosure, terms necessary for describing the operation of the audio device according to the embodiments are defined. An audio device may mean an electronic device including a speaker for outputting an audio signal. An audio signal may mean a sound wave output from an audio device. A first microphone as a feedback microphone may mean a microphone disposed on a surface of a housing including a protruding unit. A second microphone as a feedforward microphone may mean a microphone disposed on a surface of a housing including a sensor. A signal inflow characteristic may mean a measure of how much an audio signal of a speaker flows into a microphone.

[0028] Hereinafter, various embodiments disclosed in this document will be described with reference to the accompanying drawings. For the convenience of description, the components shown in the accompanying drawings may be exaggerated or minimized, and the present invention is not necessarily limited thereto.

[0029] Figure 1 An example of a state in which an audio device according to an embodiment is close to a user's body is shown.

[0030] Reference Figure 1, when the audio device 100 is not used, the audio device 100 can be accommodated and stored in the power supply device 200, and when the audio device 100 is used, the audio device 100 can be worn on a part of the user's body (e.g., ear) and close to the part of the user's body (e.g., ear). According to an embodiment, the audio device 100 can be configured as a pair to be worn on both ears of the user and close to both ears of the user. For example, the audio device 100 may include a right audio device 100a that can be worn on the right ear of the user and close to the right ear of the user, and a left audio device 100b that can be worn on the left ear of the user and close to the left ear of the user. According to an embodiment, the audio device 100 can output an audio signal in a state of being worn on a part of the user's body and close to a part of the user's body. According to an embodiment, at least one of the right audio device 100a and the left audio device 100b can output an audio signal using wireless data transmission / reception performed with an electronic device. For example, the path of wireless data transmission / reception may include a path for a Bluetooth communication scheme, a path for a Bluetooth low energy communication scheme, a path for an ultra-wideband communication scheme, a path for a wireless fidelity (Wi-Fi) direct communication scheme, and at least one of a path for a mobile communication scheme (e.g., a long term evolution (LTE) side link). According to an embodiment, only one of the paired audio devices 100a and 100b can generate a communication path with an electronic device. For example, an electronic device may be connected to a right audio device 100a among paired audio devices 100a and 100b. The right audio device 100a may output an audio signal based on audio data of the electronic device received through the communication path. In the case where the electronic device is connected to the right audio device 100a, the electronic device or the right audio device 100a may provide information about the communication path to the left audio device 100b so that the left audio device 100b may output an audio signal. The left audio device 100b may receive or sniff data sent to the right audio device 100a based on the information about the communication path, and output an audio signal. For example, the left audio device 100b can receive data sent to the right audio device 100a by monitoring the information on the communication path. According to an embodiment, the right audio device 100a connected to the electronic device can be referred to as a master device, and the left audio device 100b not connected to the electronic device can be referred to as a slave device. According to an embodiment, the master device and the slave device among the paired audio devices 100a and 100b can be switched. According to an embodiment, at least one of the paired audio devices 100a and 100b can send data to the electronic device. For example, the data may include information (e.g., information on playing a sound source, information on pausing a sound source, information on stopping a sound source, information on controlling the volume (e.g., volume up, volume down), and information on selecting a sound source).

[0031] Figure 2 An example of a state in which an audio device according to an embodiment is connected to a power supply device is shown.

[0032] Reference Figure 2 , the power supply device 200 may have an openable and closable structure. According to an embodiment, in response to an operation of turning on the power supply device 200, the power supply device 200 may perform a trigger operation for Bluetooth pairing with the audio device 100. According to an embodiment, the audio device 100 may generally include a small and rechargeable battery to provide mobility. Therefore, the audio device 100 may be connected to a separate power supply device 200 and stored in the separate power supply device 200 to prevent loss when the audio device 100 is not in use. According to an embodiment, the audio device 100 may charge the battery while being connected to the power supply device 200 and stored in the power supply device 200. According to an embodiment, although in Figure 2 Although not shown in the figure, the audio device 100 may include a detectable member corresponding to the sensor of the power supply device 200. For example, the power supply device 200 may include a Hall sensor (or a Hall IC), and the audio device 100 may include a magnet. According to an embodiment, in a case where the audio device 100 is accommodated in the power supply device 200, the Hall sensor of the power supply device 200 may recognize the magnet installed in the audio device 100 and output a signal related to the combination of the power supply device 200 and the audio device 100. According to an embodiment, although in Figure 2 Although not shown in the figure, the audio device 100 may include at least one conductive pin pad outside the audio device 100. Figure 2 Although not shown in the figure, the power supply device 200 may include at least one conductive pin (e.g., a conductive terminal) outside the power supply device 200. The conductive pin pad included in the audio device 100 and the conductive pin included in the power supply device 200 may be arranged to be in physical contact with each other in a state where the audio device 100 is connected to the power supply device 200. According to an embodiment, in a case where the audio device 100 is connected to the power supply device 200, the conductive pin of the audio device 100 and the conductive pin of the power supply device 200 may be in contact with each other to be electrically connected. According to an embodiment, the audio device 100 or the power supply device 200 may determine the connection state between the audio device 100 and the power supply device 200 by recognizing the contact of the conductive pin.

[0033] According to an embodiment, although Figure 2Although not shown in the figure, the audio device 100 can determine whether the audio device 100 is connected to the power supply device 200 by sensing the amount of light reflected from the power supply device 200 by the proximity sensor. According to an embodiment, by processing the reflective structure of the power supply device 200 with a color having a high reflectivity, the accuracy of sensing an object approaching the audio device 100 can be improved. According to an embodiment, in the case where the power supply device 200 is configured with various colors, the power supply device 200 can be configured so that the color of the power supply device 200 and the color of the reflective structure of the power supply device 200 are visually the same or similar by adjusting the transmittance of the filter. According to an embodiment, the audio device 100 can distinguish the sensing result values ​​of the power supply device 200 and the user by adjusting the power of the proximity sensor of the audio device 100 and performing proximity sensing.

[0034] Figure 3 is a block diagram illustrating components of an audio device according to an embodiment. Figure 3 The configuration example in can be understood as Figure 1 The configuration of the audio device mentioned in (eg, the right audio device 100a or the left audio device 100b).

[0035] Reference Figure 3 , the audio device 300 (eg Figure 1 The audio device 100, the left audio device 100a and the right audio device 100b) may include a speaker 301, a filter circuit 303, a processor 305, a sensor 307, a first microphone 309 and a second microphone 311. According to an embodiment, the audio device 300 may include a plurality of electronic components arranged in the internal space. For example, the audio device 300 may include a speaker 301, a filter circuit 303, a processor 305, a sensor 307, a first microphone 309 and a second microphone 311. However, the present invention is not limited thereto and may further include electronic components other than electronic components. According to an embodiment, the audio device 300 may be an electronic device for outputting an audio signal. For example, the audio device 300 may be a wired headset. For example, the audio device 300 may be a true wireless stereo (TWS) headset.

[0036] According to an embodiment, the audio device 300 may include a speaker 301. The speaker 301 may output an audio signal. The speaker 301 may receive an electrical signal. The speaker 301 may include an element for obtaining the electrical signal. The speaker 301 may convert the electrical signal into a sound wave signal. The speaker 301 may include an element for converting the electrical signal into a sound wave signal. The speaker 301 may output an audio signal including the converted sound wave signal. The speaker 301 may include an element for outputting an audio signal.

[0037] According to an embodiment, the filter circuit 303 may be an element that adjusts the strength of the output signal according to the frequency of the input signal. The ratio of the strength of the input signal to the strength of the output signal may be determined based on the gain of the filter circuit 303. Therefore, the strength of the output signal may be determined based on the gain of the filter circuit 303. Since the gain of the filter circuit may vary according to the frequency of the input signal, the strength of the output signal may vary according to the frequency. According to an embodiment, at least one processor 305 may change the gain of the filter circuit 303 by changing the characteristics of multiple partial filter circuits of the filter circuit 303. The filter circuit 303 may include multiple partial circuits. According to an embodiment, in order to change the gain of the filter circuit 303 according to the frequency, at least one processor may activate at least one partial filter circuit of the multiple partial filter circuits and deactivate at least another partial filter circuit. According to an embodiment, in order to change the gain of the filter circuit 303 according to the frequency, at least one processor may change the weight of each of the multiple partial filter circuits. In the following, Figure 8a , Figure 8b and Figure 8c A method of changing the gain of a filter circuit based on changes in characteristics of multiple partial filter circuits is shown.

[0038] According to an embodiment, the audio device 300 may include a processor 305. The processor 305 may be implemented with one or more integrated circuit (IC) chips, and may perform various data processing. For example, the processor 305 may be implemented as a system on chip (SoC). The processor 305 may include a central processing unit (CPU), a graphics processing unit (GPU), a neural processing unit (NPU), an image signal processor (ISP), a display controller, a memory controller, a storage controller, an application processor (AP), a communication processor (CP) and / or a subcomponent including a sensor interface. The subcomponents are exemplary only. For example, the processor 305 may also include other subcomponents. For example, some subcomponents may be omitted from the processor 305.

[0039] According to an embodiment, the processor 305 may detect a wearing state through a sensor 307 described later. The processor 305 may control components according to the wearing state of the audio device 300. The processor 305 may output an audio signal through the speaker 301. According to an embodiment, the processor 305 may receive audio data from an external device (e.g., a server, a smart phone, a PC, a PDA, or an access point). The processor 305 may be designed to store the received audio data in a memory (not shown). For example, the processor 305 may receive non-volatile audio data (or download audio data) from an external device. The processor 305 may store the received non-volatile audio data in a non-volatile memory. In addition, for example, the processor 305 may receive volatile audio data (or streaming audio data) from an external device. The processor 305 may store the received volatile audio data in a volatile memory. The processor 305 may reproduce the audio data (e.g., non-volatile audio data or volatile audio data) stored in the memory and output the audio data through the speaker 301. The processor 305 may obtain an audio signal by decoding the audio data (audio data reproduction), and output the obtained audio signal through the speaker 301 .

[0040] According to an embodiment, the audio device 300 may include a sensor 307. The sensor 307 may receive physical data related to the audio device 300. For example, the sensor 307 may receive data related to the wearing state of the audio device 300. For example, the sensor 307 may identify the presence or absence of a touch input input to the audio device 300. For example, the sensor 307 may identify the pressure of the touch input input to the audio device 300. The sensor 330 may convert the measured or detected information into an electrical signal. The sensor 307 may provide various information to the processor 305 according to the type of the sensor. According to an embodiment, the sensor 307 may include a touch sensor. The sensor 307 may detect the touch input of the user. The sensor 307 may provide the processor 305 with the result of detecting the touch input. According to an embodiment, the sensor 307 may include a grip detection sensor. The sensor 307 may detect the grip of the user. The sensor 307 may provide the processor 305 with the result of detecting the grip. According to an embodiment, the sensor 307 may include a pressure sensor. The sensor 307 may detect the pressure caused by the user or an external object. The sensor 307 may provide the processor 305 with the result of detecting the pressure.

[0041] The information provided by the sensor 307 may be used by the processor 305 to perform various operations. The processor 305 may recognize whether the audio device 300 is connected to the power supply device 200 based on the information obtained from the sensor 307. According to an embodiment, the processor 305 may recognize whether the audio device 300 is worn on a part of the user's body and close to a part of the user's body based on the information obtained from the sensor 307. According to an embodiment, the processor 305 may recognize whether the wearing state of the audio device 300 has changed based on the information obtained from the sensor 307.

[0042] According to an embodiment, the audio device 300 may include a first microphone 309 and a second microphone 311. The audio device 300 may include the first microphone 309. For example, the first microphone 309 may be provided in the region of the protruding unit of the audio device 300. The first microphone 309 may be referred to as a feedback microphone because the audio device 300 is provided adjacent to the speaker when the user wears it. In addition, the first microphone 309 may be referred to as an error microphone. The audio device 300 may include a second microphone 311. In addition, for example, the second microphone 311 may be provided in the region of the housing including the sensor (e.g., sensor 307) of the audio device 300. The second microphone 311 may be referred to as a feedforward microphone because the audio device 300 is provided toward the outside when the user wears it. In addition, the second microphone 311 may be referred to as a reference microphone.

[0043] The first microphone 309 may receive a noise signal to adjust the audio signal. The second microphone 311 may receive an external signal to adjust the audio signal. For example, the first microphone 309 may be used in an active noise cancellation (ANC) function for removing external noise. For example, the second microphone 311 may be used in an active noise cancellation (ANC) function for removing external noise. In order to eliminate the noise signal received from the first microphone 309 or the second microphone 311, at least one processor (e.g., processor 305) may generate a tuning signal. The tuning signal may be generated based on the second phase information of the first phase information for eliminating the noise signal. For example, the second microphone 311 may be used in an ambient sound enabling function or a personal sound amplification product (PSAP) function for listening to ambient sound. In order to amplify the external signal received from the second microphone, at least one processor 305 may generate a tuning signal. The tuning signal may be generated based on the second phase information of the first phase information for amplifying the external signal. According to the degree of amplification of the external signal received from the second microphone, the ambient sound enabling function and the PSAP function may be distinguished from each other. The ambient sound enabling function may include a surrounding sound listening function, an environment function, a transparency function, and the like. In the case of operating the ambient sound enabling function, the at least one processor 305 may amplify the external signal received from the second microphone to the strength of the signal received by the user when the earplug is not worn. In the case of operating the PSAP function, the at least one processor 305 may amplify the external signal received from the second microphone to the strength of the signal received by the user when the earplug is not worn.

[0044] Figure 4 An example of a wearable audio device according to an embodiment is shown.

[0045] Reference Figure 4 The audio device 401 (eg, the audio device 100 or the audio device 300) may be an electronic device for outputting an audio signal. The protrusion unit 403 may be a device for outputting an audio signal through a speaker (eg, Figure 3 The speaker 301 of the embodiment of the present invention may be a protruding structure for outputting an audio signal. The touch sensor 405 may detect a touch input of a user. The external auditory canal 407 may be a channel through which the audio signal is transmitted when the audio device 401 is worn. The speaker port 409 may be a vent for improving the performance of the speaker 301 by adjusting the air pressure. The audio signal may also be transmitted through the speaker port 409. The first microphone 411 (e.g. Figure 3 The first microphone 309 of the embodiment of the present invention can be a feedback microphone. The first microphone 411 can be called an error microphone. The second microphone 413 (e.g., Figure 3The second microphone 311 of the embodiment may be a feed-forward microphone. The second microphone 413 may be referred to as a reference microphone. The charging terminal 415 may be connected to a power supply device (e.g., Figure 2 A conductive pad corresponding to a conductive pin (eg, a conductive terminal) of the power supply device 200 .

[0046] The processor (e.g., processor 305) may recognize a touch input by a user through touch sensor 405. Processor 305 may control the operation of audio device 401 based on the touch input. For example, in the case where touch input is input once to touch sensor 405, processor 305 may pause the audio signal being played. For example, in the case where touch input is input twice to touch sensor 405, processor 305 may play the paused audio signal again.

[0047] The speaker port 409 may be a vent for improving the performance of the speaker 301 by adjusting the air pressure. According to an embodiment, since the performance of the speaker 301 varies depending on the degree to which the speaker port 409 is blocked, howling may occur when an active noise cancellation (ANC) function for removing external noise is used. According to an embodiment, since an audio signal may also be transmitted through the speaker port 409, howling may occur when an ambient sound allowing function or a personal sound amplification product (PSAP) function for hearing ambient sounds is used. This is because the audio signal output from the speaker port 409 may flow back into the second microphone 413, and resonance may occur. Figure 5 The cause of howling in each function is described in.

[0048] The first microphone 411 may be a feedback microphone disposed on a surface of the housing to which the protruding unit is coupled. According to an embodiment, the first microphone 411 may be used in an active noise cancellation (ANC) function for removing external noise. In order to eliminate the noise signal received from the first microphone 411, the processor 305 may generate a tuning signal. The tuning signal may be generated based on the second phase information of the first phase information for eliminating the noise signal. For example, the first phase information may be the phase of the noise signal. The second phase information may be the phase of the tuning signal. The phase of the tuning signal may be opposite to the phase of the noise signal.

[0049] The second microphone 413 may be a reference microphone disposed on a surface of the housing to which the touch sensor 405 is coupled. According to an embodiment, the second microphone 413 may be used in an active noise cancellation (ANC) function for removing external noise. In order to eliminate the noise signal received from the second microphone 413, the processor 305 may generate a tuning signal. The tuning signal may be generated based on the second phase information of the first phase information for eliminating the noise signal. For example, the first phase information may be the phase of the noise signal. The second phase information may be the phase of the tuning signal. The phase of the tuning signal may be opposite to the phase of the noise signal. According to an embodiment, the second microphone 413 may be used in an ambient sound allowing function or a personal sound amplification product (PSAP) function for hearing ambient sound. In order to amplify the external signal received from the second microphone 413, the processor 305 may generate a tuning signal. The tuning signal may be generated based on the second phase information of the first phase information for amplifying the external signal. For example, the first phase information may be the phase of the external signal. The second phase information may be the phase of the tuning signal. The phase of the tuning signal may be the same as the phase of the external signal.

[0050] The charging terminal 415 may be connected to a power supply device (eg, Figure 2 The audio device 401 may include at least one external conductive pin pad. The power supply device 200 may include at least one external conductive pin (e.g., conductive terminal). The conductive pin pad included in the audio device 401 and the conductive pin included in the power supply device 200 may be arranged to be in physical contact with each other in a state where the audio device 401 is connected to the power supply device 200. In the case where the audio device 401 is connected to the power supply device 200, the conductive pad of the audio device 401 and the conductive pin of the power supply device 200 may be in contact with each other to be electrically connected. By identifying the conductive pin contact, the audio device 401 or the power supply device 200 can determine the state where the audio device 401 is connected to the power supply device 200.

[0051] Figure 5 An example of movement of an audio device according to an embodiment is shown. When an audio device (e.g., audio device 100, audio device 300, and audio device 401) moves, an audio signal output from a speaker (e.g., speaker 301) may be input to a microphone. For example, in the case where a signal output for an ANC function, an ambient sound enabling function, or a PSAP function is re-input through a microphone, a delayed signal may cause undesirable constructive interference. Constructive interference may cause howling.

[0052] Reference Figure 5The audio device 501 (eg, the audio device 300 and the audio device 401) may be an electronic device for outputting an audio signal. The speaker port 503 (eg, Figure 4 The speaker port 409 of the speaker 501 may be a vent hole for improving the performance of the speaker 301 by adjusting the air pressure. The audio signal of the audio device 501 may be emitted through the speaker port 503. The protruding unit 505 (eg, Figure 4 The protruding unit 403) may be a protruding structure for a user to wear and transmit an audio signal.

[0053] The audio device 501 may include a first microphone 507 (eg, Figure 3 The first microphone 309 and Figure 4 The first microphone 507 may be provided on the surface of the protruding unit 505 of the housing including the audio device 501. The first microphone 507 may be referred to as a feedback microphone or an error microphone. The first microphone 507 may be used as an active noise cancellation (ANC) function for removing external noise. The audio device 501 may include a second microphone 509 (e.g., Figure 3 The second microphone 311 and Figure 4 The second microphone 509 may be disposed on a surface of the housing including the sensor of the audio device 501. The second microphone 509 may be referred to as a feedforward microphone or a reference microphone. The second microphone 509 may be used for an ANC function, an ambient sound enabling function, or a personal sound amplification product (PSAP) function.

[0054] According to an embodiment, the first microphone 507 may cause howling. At least one processor (e.g., the processor 305) may receive an audio signal output from a speaker in the protruding unit 505 or an audio signal output from the speaker port 503 through the first microphone 507. The processor 305 may reduce the influence of howling by using a filter circuit. Howling may occur when an audio signal from a speaker flows into the microphone. The signal inflow characteristic may indicate the degree to which the audio signal from the speaker flows into the microphone. If the signal inflow characteristic changes, the setting of the filter circuit for reducing the influence of howling is changed. The changed setting of the filter circuit may cause howling again.

[0055] For example, an audio signal may be output from a speaker in the protruding unit 505. The audio signal may be input to the first microphone 507. In order to reduce the howling caused by the input of the audio signal, the processor 305 may determine the characteristics of the filter circuit optimized according to the signal inflow characteristics. Through the filter circuit, the processor 305 may reduce the intensity of the signal of the frequency at which howling is likely to occur. The characteristics of the filter circuit may be a gain according to the frequency. Therefore, in a general wearing state, even if the audio signal output from the speaker in the protruding unit 505 is input to the first microphone 507, howling may not occur. However, if the wearing state changes, howling may occur. For example, in the case where a user's touch input is detected in the audio device 501, the amount of blockage of the speaker port may change. Due to the change in the amount of blockage of the speaker port, the air pressure in the audio device 501 may change. The change in air pressure may change the signal inflow characteristics of the microphone. In addition, for example, in the case where a user's touch input is detected in the audio device 501, a change in the volume of the external auditory canal may occur. In addition, for example, if pressure caused by the user's grip or an external object is detected in the audio device 501, the amount of blockage of the speaker port may change. The signal inflow characteristic may change due to a change in the amount of blockage of the speaker port. In addition, for example, if pressure caused by the user's grip or an external object is detected in the audio device 501, a change in the volume of the external auditory canal may occur. The signal inflow characteristic may change due to a change in the volume of the external auditory canal. When the signal inflow characteristic changes, it is difficult to reduce the howling of the audio device 501 in which the wearing state has changed, depending on the setting of the filter circuit before the wearing state changes. Therefore, if the wearing state changes, howling may occur again due to a change in the amount of blockage of the speaker port or the volume of the external auditory canal.

[0056] For example, an audio signal may be emitted from the speaker port 503. The audio signal may be introduced into the first microphone 507. In order to reduce the howling caused by the input of the audio signal, the processor 305 may determine the characteristics of the filter circuit optimized according to the signal inflow characteristic. Through the filter circuit, the processor 305 may reduce the intensity of the signal of the frequency at which howling is likely to occur. The characteristic of the filter circuit may be a gain according to the frequency. Therefore, in a general wearing state, even if the audio signal output from the speaker port 503 is input to the first microphone 507, howling may not occur. However, if the wearing state changes, howling may occur. For example, in the case where a user's touch input is detected in the audio device 501, the amount of blockage of the speaker port may change. The signal inflow characteristic may change due to a change in the amount of blockage of the speaker port. In addition, for example, if pressure caused by the user's grip or an external object is detected in the audio device 501, the amount of blockage of the speaker port may change. Due to the change in the amount of blockage of the speaker port, the signal inflow characteristic may change. When the signal inflow characteristic changes, it is difficult to reduce the howling of the audio device 501 in which the wearing state has changed, depending on the setting of the filter circuit before the wearing state changes. Therefore, if the wearing state changes, howling may occur again due to the change in the amount of blockage of the speaker port or the volume of the external auditory canal. Figure 6a In the following, the relationship between the amount of speaker port blocking and the signal inflow characteristics will be described. Figure 6b In this article, the relationship between the external auditory canal volume and the signal inflow characteristics will be described.

[0057] According to an embodiment, howling may occur in the second microphone 509. As with the first microphone 507, if an audio signal output from the speaker in the protruding unit 505 or an audio signal output from the speaker port 503 is input to the second microphone 509, howling may occur. Howling may occur when an audio signal from the speaker flows into the microphone. The signal inflow characteristic may indicate the degree to which the audio signal from the speaker flows into the microphone. If the signal inflow characteristic changes, the setting of the filter circuit for reducing the influence of the howling is changed. The changed setting of the filter circuit may cause howling again.

[0058] According to an embodiment, due to the structure of the audio device 501, the audio signal output from the speaker in the protruding unit 505 is difficult to be input to the second microphone 509. Therefore, howling may not occur in a general wearing state. However, in the case of adjusting the wearing state of the audio device 501 or touching the audio device 501 for touch input, the coverage degree of the speaker changes, so the signal inflow characteristic may change. In the case of adjusting the wearing state of the audio device 501, the signal inflow characteristic may change. That is, the audio signal output from the speaker in the protruding unit 505 is input to the second microphone 509, and therefore howling may occur.

[0059] According to an embodiment, due to the structure of the audio device 501, the audio signal output from the speaker port 503 is difficult to be input to the second microphone 509. Therefore, howling may not occur in a general wearing state. However, if the wearing state changes, howling may occur. For example, in the case where a user's touch input is detected in the audio device 501, the coverage amount of the speaker port may change.

[0060] In the case of adjusting the wearing state of the audio device 501 or touching the audio device 501 for touch input, the signal inflow characteristics may change due to the change in the coverage degree of the speaker port 503. In the case of adjusting the wearing state of the audio device 501, the signal inflow characteristics may change. That is, the audio signal output from the speaker port 503 is input to the second microphone 509, and thus howling may occur.

[0061] Figure 6a An example of the signal inflow characteristics through the secondary path according to the blocking amount of the speaker port is shown.

[0062] Reference Figure 6a , graph 600 may represent the speaker port (e.g., Figure 4 The speaker port 409 and Figure 5 The horizontal axis of graph 600 represents frequency (unit: Hertz (Hz)), and the vertical axis of graph 600 represents gain (unit: decibel (dB)). The air pressure in the audio device 501 may change due to the change in the amount of blockage of the speaker port. The change in air pressure can change the signal inflow characteristics of the microphone. For example, the signal inflow characteristics through the secondary path can be obtained based on the ratio of the strength of the received signal to the strength of the transmitted signal.

[0063] The signal inflow characteristic through the main path may be a result of comparing a signal received through the first microphone and a signal received through the second microphone. The signal inflow characteristic through the secondary path may be obtained by inputting the audio signal of the speaker into the first microphone. Hereinafter, the signal inflow characteristic refers to the signal inflow characteristic through the secondary path.

[0064] Data 601 is a signal inflow characteristic according to a frequency measured when the speaker port blocking amount is approximately 100%. Data 602 is a signal inflow characteristic according to a frequency measured when the speaker port blocking amount is approximately 90%. Data 603 is a signal inflow characteristic according to a frequency measured when the speaker port blocking amount is approximately 70%. Data 604 is a signal inflow characteristic according to a frequency measured when the speaker port blocking amount is a default value (e.g., 10%).

[0065] As the amount of speaker port blocking increases, it can be confirmed that the signal inflow characteristics of the frequency segment 605 increase. Higher frequencies have shorter wavelengths, and therefore the influence caused by the time delay of the incoming signal increases. Therefore, it may be difficult to remove external noise by the active noise cancellation (ANC) function. In particular, at frequencies above 1000Hz, it is difficult to remove external noise by the ANC function, and howling may occur. As the amount of speaker port blocking increases, the audio device (e.g., the audio device 501) can reduce the howling by filtering the audio signal in the frequency segment 605 via a filter circuit. For example, as the amount of speaker port blocking increases, the audio device 501 can reduce the gain of the input signal in a specific frequency range (e.g., approximately 1000Hz to 3000Hz) at the frequency segment 605 through a filter circuit.

[0066] In the case where the wearing state of the audio device 501 is adjusted or the audio device 501 is touched for touch input, the speaker port blocking amount may be changed. Figure 4 In the case where the touch detection sensor 405 of the audio device 501 recognizes a touch input, the audio device 501 can recognize it as a change in the amount of blocking of the speaker port. Therefore, the audio device 501 can reduce the gain of the filter circuit at the frequency segment 605.

[0067] Figure 6b An example of signal inflow characteristics according to the volume of the external auditory canal is shown.

[0068] Reference Figure 6b , the graph 650 may represent the external auditory canal (e.g., Figure 4The signal inflow characteristic of the volume of the external auditory canal 407 is shown in FIG650 . The horizontal axis of graph 650 represents frequency (unit: Hertz (Hz)), and the vertical axis of graph 650 represents signal inflow characteristic (unit: decibel (dB)). If the volume of the external auditory canal changes, the resonant frequency of the audio device 501 may change. For example, if the volume of the external auditory canal increases, the resonant frequency may also increase. A change in the resonant frequency may change the signal inflow characteristic. For example, the signal inflow characteristic may be obtained based on the ratio of the strength of the received signal to the strength of the transmitted signal.

[0069] Data 651 is a signal inflow characteristic according to a frequency measured when the volume of the external auditory canal is the largest. Data 651, data 652, data 653, data 654, data 655, data 656, data 657, data 658, and data 659 are, in order, signal inflow characteristics according to frequencies measured when the volume of the external auditory canal is large. Data 659 is a signal inflow characteristic according to a frequency measured when the volume of the external auditory canal is the smallest. It can be confirmed that the signal inflow characteristic of the frequency segment 665 increases as the volume of the external auditory canal decreases. The higher the frequency, the shorter the wavelength, which is greatly affected by time delay, and therefore, it may be difficult to remove external noise by using the ANC function. In particular, at frequencies higher than 1000Hz, it is difficult to remove external noise by the ANC function, and howling is likely to occur. Therefore, as the volume of the external auditory canal decreases, the audio device 501 can reduce howling by filtering the audio signal of the frequency range 665 through the filter circuit. For example, as the volume of the external auditory canal decreases, the audio device 501 may reduce the gain of the input signal in a specific frequency range (eg, approximately 1000 Hz to 3000 Hz) at the frequency range 665 through a filter circuit.

[0070] When the wearing state of the audio device 501 is adjusted or the audio device 501 is touched for touch input, the volume of the external auditory canal may be changed. In particular, when touch input occurs, the audio device 501 is pushed into the external auditory canal, so the volume of the external auditory canal may be reduced. Therefore, in order to prevent whistling, when the wearing detection sensor (e.g. Figure 4 When the touch detection sensor 405 of the audio device 501 recognizes the touch input, the audio device 501 can recognize that the volume of the external auditory canal has changed. Therefore, when the touch input is recognized, the audio device 501 can reduce the gain of the filter circuit at the frequency range 665.

[0071] As described above, howling may occur due to a change in the signal inflow characteristics by an operation such as receiving a touch input or adjusting a wearing state. In order to reduce the influence of howling even if the signal inflow characteristics are changed, the audio device 501 according to the embodiment may change the setting of the filter circuit to reduce the signal gain in the frequency range causing howling. Figure 7 , Figure 8a and Figure 8b A method of changing the settings of the filter circuit is described in .

[0072] Figure 7 A functional configuration of an audio device according to an embodiment is shown.

[0073] Reference Figure 7 , an audio device (e.g., audio device 501) may include a first microphone 701, a second microphone 703, and a speaker 711. The first microphone 701 may receive noise for ANC in the audio device 501. In addition, the first microphone 701 may be positioned adjacent to the speaker 711 of the audio device 501 to receive the output of the speaker 711. The first microphone 701 may be referred to as a feedback microphone or an error microphone. The second microphone 703 may receive noise for ANC or receive ambient sound for an ambient sound enabling function or a PSAP. In addition, the second microphone 703 may be positioned adjacent to a sensor of the audio device 501 to receive a signal from outside the audio device 501. The second microphone 703 may be referred to as a feedforward microphone or a reference microphone. The speaker 711 may send an audio signal.

[0074] The audio device 501 may include a codec 705. The codec 705 refers to a component (e.g., encoder, decoder) for converting a digital signal into a voice signal or converting a voice signal into a digital signal. The codec 705 may change the setting of a filter of the codec 705 based on a control signal from the processor 707.

[0075] The audio device 501 may include a processor 707. The processor 707 may send a control signal for changing the filter setting to the codec 705 based on the detection result from the sensor 709. The audio device 501 may include a sensor 709. According to an embodiment, the sensor 709 may be a sensor for detecting a touch input. The processor 707 may recognize a change in a wearing state of the audio device based on the touch input. In addition, according to an embodiment, the sensor 709 may be a sensor for detecting a user's grip. The processor 707 may recognize a change in a wearing state of the audio device based on the grip. In addition, according to an embodiment, the sensor 709 may be a sensor for measuring external pressure. The processor 707 may recognize a change in a wearing state of the audio device based on the external pressure.

[0076] In the case where the audio signal output from the speaker 711 is input to the first microphone 701 or the second microphone 703 and output again through the speaker 711, howling may occur. Therefore, in order to prevent the howling, the processor 707 may adjust the signal sent to the speaker 711 based on the change in the wearing state. The processor 707 may adjust the signal sent to the speaker 711 through the codec 705. The codec 705 adjusts the signal sent to the speaker 711 by changing the gain of the filter circuit included in the codec 705.

[0077] like Figure 6a and Figure 6b As described above, in the case of a change in the wearing state based on touch input recognition, the intensity of the audio signal in the frequency segment susceptible to howling can be increased. Therefore, by reducing the gain of the signal received by the microphone in the frequency range susceptible to howling, howling can be prevented. Figure 8a , Figure 8b and Figure 8c A method of changing the settings of the filter circuit to reduce the gain of the signal in this frequency range is described.

[0078] Figure 8a An example of a functional configuration of an audio device including a filter circuit combination unit according to an embodiment is shown.

[0079] refer to Figure 8a , the audio device (eg, the audio device 501) may include a first microphone 701, a second microphone 703, and a speaker 711. For the first microphone 701, the second microphone 703, and the speaker 711, reference may be made to Figure 7 Description.

[0080] The audio device 501 may filter the audio signal according to the frequency. For example, the codec (e.g., Figure 7 The codec 705 ) may include a first filter circuit unit 801 and a second filter circuit unit 803 .

[0081] The audio device 501 may include a first filter circuit unit 801. The first filter circuit unit 801 may include a first amplifier 801a and a first filter circuit 801b. The first amplifier 801a may control the gain of the input signal. For example, the first amplifier 801a may reduce the gain of the signal. The first filter circuit 801b may filter the signal within a specific frequency range from the signal. The first filter circuit 801b may perform filtering so as to reduce the intensity of the signal within a specified range of expected howling. When performing an ANC function, an ambient sound allowing function, or a PSAP function, the first filter circuit unit 801 may filter the audio signal received through the second microphone 703 according to the frequency. Since the signal is filtered at a specific frequency, the howling can be reduced.

[0082] The audio device 501 may include a second filter circuit unit 803. The second filter circuit unit 803 may include a second amplifier 803a and a second filter circuit 803b. The second amplifier 803a may control the gain of the input signal. For example, the second amplifier 803a may reduce the gain of the signal. The second filter circuit 803b may filter a signal within a specific frequency range from the signal. For example, the second filter circuit 803b may perform filtering to reduce the intensity of the signal within a specified range of expected howling. When performing an active noise cancellation (ANC) function, the second filter circuit unit 803 may filter the audio signal received by the first microphone 701 according to the frequency. Since the signal is filtered at a specific frequency, the howling can be reduced.

[0083] According to an embodiment, the processor 707 may receive the detection result through the sensor 709. According to an embodiment, the sensor 709 may detect a touch input of the user through a touch sensor. According to an embodiment, the sensor 709 may detect gripping through a grip detection sensor. According to an embodiment, the sensor 709 may detect pressure of an external object or a user through a pressure sensor.

[0084] The processor 707 may recognize a change in the wearing state of the audio device 501 based on the detection result. When the wearing state of the audio device 501 changes, the signal inflow characteristic may change. Due to the changed signal inflow characteristic, the audio signal output from the speaker 711 may be input to the first microphone 701 or the second microphone 703. When the input audio signal is output again through the speaker 711, howling may occur. Therefore, in order to prevent howling, the processor 707 may adjust the characteristics of the audio signal output again through the speaker 711 based on the change in the wearing state.

[0085] According to an embodiment, the processor 707 may change the gain of the first filter circuit unit 801 as a whole. The processor 707 may change the gain of the first filter circuit unit 801 as a whole, regardless of the frequency. For example, the processor 707 may reduce the gain of the first filter circuit unit 801 as a whole. According to an embodiment, the processor 707 may change the gain of the first filter circuit unit 801 according to the frequency. For example, the processor 707 may reduce the gain of the first filter circuit unit 801 within a specific frequency range.

[0086] According to an embodiment, the processor 707 may change the gain of the second filter circuit unit 803 as a whole. The processor 707 may change the gain of the second filter circuit unit 803 as a whole, regardless of the frequency. For example, the processor 707 may reduce the gain of the second filter circuit unit 803 as a whole. According to an embodiment, the processor 707 may change the gain of the second filter circuit unit 803 according to the frequency. For example, the processor 707 may reduce the gain of the second filter circuit unit 803 within a specific frequency range.

[0087] Figure 8b An example of a functional configuration of an audio device including a portion of a filter circuit according to an embodiment is shown. Figure 8a Differently, the gain of a signal can be controlled by selecting a portion of a filter circuit of a filter circuit unit rather than changing the gain of the entire filter circuit.

[0088] Reference Figure 8b , the audio device (eg, the audio device 501) may include a first microphone 701, a second microphone 703, and a speaker 711. For the first microphone 701, the second microphone 703, and the speaker 711, reference may be made to Figure 7 Description.

[0089] The audio device 501 may filter the audio signal according to the frequency. For example, the codec (e.g., Figure 7 The codec 705 ) may include a first filter circuit unit 851 and a second filter circuit unit 853 .

[0090] The audio device 501 may include a first filter circuit unit 851. The first filter circuit unit 851 may include a first switch 851a and a partial filter circuit. The partial filter circuit may include a first partial filter circuit 851b, a second partial filter circuit 851c ... nth partial filter circuit 851d. The first switch 851a may connect one of the partial filter circuits. The first switch 851a may change the currently connected partial filter circuit among the partial filter circuits to another partial filter circuit based on a control command from the processor 707. For example, the first switch 851a may change the connected partial filter circuit from the second partial filter circuit 851c to the first partial filter circuit 851b based on a control command from the processor 707. When the ANC function, the ambient sound allowing function, or the PSAP function is performed, the first filter circuit unit 851 may filter the audio signal received by the second microphone 703 according to the frequency. When the signal is filtered at a specific frequency, howling can be reduced.

[0091] The audio device 501 may include a second filter circuit unit 853. The second filter circuit unit 853 may include a second switch 853a and a partial filter circuit. The partial filter circuit may include a first partial filter circuit 853b, a second partial filter circuit 853c ... nth partial filter circuit 853d. The first switch 853a may connect one of the partial filter circuits. The first switch 853a may change the currently connected partial filter circuit among the partial filter circuits to another partial filter circuit based on the control command of the processor 707. For example, the first switch 853a may change the connected partial filter circuit from the second partial filter circuit 853c to the first partial filter circuit 853b based on the control command of the processor 707. When the ANC function is performed, the second filter circuit unit 853 may filter the audio signal received by the first microphone 701 according to the frequency. When the signal is filtered at a specific frequency, howling can be reduced.

[0092] According to an embodiment, the processor 707 can switch the partial filter circuit used among the partial filter circuits of the first filter circuit unit 851 from a partial filter circuit to another partial filter circuit. Due to external input (e.g., touch input, grip detection, pressure), the signal inflow characteristics can vary, and the filtering frequency and filtering gain provided from each partial filter circuit can be independent. For example, the filtering characteristics of the first partial filter circuit 851b and the filtering characteristics of the second partial filter circuit 851c can be different. The first partial filter circuit 851b can reduce the pass gain of the signal within a first frequency range, while the second partial filter circuit 851c can reduce the pass gain of the signal within a second frequency range. The processor 707 can identify the partial filter circuit so as to reduce the gain of the signal within a desired frequency range. The processor 707 can connect the identified partial filter circuit to the second microphone 703 via the first switch 851a. In Figure 8b , the first switch 851a is illustrated, but the selection of the partial filter circuits may be implemented in another manner. For example, the processor 707 may activate one of the partial filter circuits of the first filter circuit unit 851 and deactivate all the remaining partial filter circuits of the first filter circuit unit 851.

[0093] According to an embodiment, the processor 707 may switch a partial filter circuit used among the partial filter circuits of the second filter circuit unit 853 from a partial filter circuit to another partial filter circuit. Due to external input (e.g., touch input, grip sensing, pressure), the signal inflow characteristics may vary, and the filtering frequency and filtering gain provided from each partial filter circuit may be independent. For example, the filtering characteristics of the first partial filter circuit 853b and the filtering characteristics of the second partial filter circuit 853c may be different. The first partial filter circuit 853b may reduce the pass gain of the signal within a first frequency range, while the second partial filter circuit 853c may reduce the pass gain of the signal within a second frequency range. The processor 707 may identify a partial filter circuit so as to reduce the gain of the signal within a desired frequency range. The processor 707 may connect the identified partial filter circuit to the second microphone 703 via the first switch 853a. Although in Figure 8b 853 a is shown in FIG. 85 , but the selection of the partial filter circuits may be implemented in another manner. For example, the processor 707 may activate one of the partial filter circuits of the second filter circuit unit 853 and deactivate all the remaining partial filter circuits of the second filter circuit unit 853 .

[0094] Figure 8c An example of a functional configuration of an audio device including a filter circuit combination unit according to an embodiment is shown.

[0095] Reference Figure 8c , the audio device (eg, the audio device 501) may include a first microphone 701, a second microphone 703, and a speaker 711. For the first microphone 701, the second microphone 703, and the speaker 711, reference may be made to Figure 7 Description.

[0096] The audio device 501 may filter the audio signal according to the frequency. For example, the codec (e.g., Figure 7 The codec 705) may include a first filter circuit combination unit 871 and a second filter circuit combination unit 873.

[0097] The audio device 501 may include a first filter circuit combination unit 871. The first filter circuit combination unit 871 may include a combination of multiple partial filter circuits. The partial filter circuit may include a first partial filter circuit, a second partial filter circuit, and an nth partial filter circuit. The first filter circuit combination unit 871 may be configured by changing the weight of each of the multiple partial filter circuits based on a control command of the processor. For example, the first filter circuit combination unit 871 may be configured such that the weight of the first partial filter circuit is 0.5, the weight of the second partial filter circuit is 0.3, and the weight of the third partial filter circuit is 0.2. The first filter circuit combination unit 871 may filter the audio signal received by the second microphone 703 according to the frequency when performing the ANC function, the ambient sound allowing function, or the PSAP function. When the signal is filtered at a specific frequency, the howling can be reduced.

[0098] The audio device 501 may include a second filter circuit combination unit 873. The second filter circuit combination unit 873 may include a combination of multiple partial filter circuits. The partial filter circuit may include a first partial filter circuit, a second partial filter circuit, and an nth partial filter circuit. The second filter circuit combination unit 873 may be configured by changing the weight of each of the multiple partial filter circuits based on a control command of the processor. For example, the second filter circuit combination unit 873 may be configured such that the weight of the first partial filter circuit is 0.5, the weight of the second partial filter circuit is 0.3, and the weight of the third partial filter circuit is 0.2. The second filter circuit combination unit 873 may filter the audio signal received by the first microphone 701 according to the frequency when performing the ANC function, the ambient sound allowing function, or the PSAP function. When the signal is filtered at a specific frequency, the howling can be reduced.

[0099] According to an embodiment, the first filter circuit combination unit 871 and the second filter circuit combination unit 873 may be configured with a plurality of partial filter circuits. According to an embodiment, in the first filter circuit combination unit 871 and the second filter circuit combination unit 873, at least one partial filter circuit of the plurality of partial filter circuits may be activated, and at least another partial filter circuit may be deactivated. According to an embodiment, the first filter circuit combination unit 871 and the second filter circuit combination unit 873 may be configured to change the weight of each of the plurality of partial filter circuits. According to an embodiment, the first filter circuit combination unit 871 and the second filter circuit combination unit 873 may be configured to change the weight of each of the plurality of partial filter circuits. According to an embodiment, the first filter circuit combination unit 871 and the second filter circuit combination unit 873 may be a combination of a plurality of partial filter circuits. For example, in at least one processor, the greater the pressure of the touch input, the higher the frequency range in which the gain of the first filter circuit combination unit 871 and the second filter circuit combination unit 873 is reduced.

[0100] Fig. 9 An example of a functional configuration of an audio device for controlling filter characteristics without a microphone according to an embodiment is shown.

[0101] Reference Fig. 9 , an audio device (e.g., audio device 501) may include a sensor 903, a processor 901, a codec 907 including a filter circuit, and a speaker 711. Even if active noise cancellation (ANC), an ambient sound enabling function, or a personal sound amplification product (PSAP) function is not activated, the processor 901 may change the sound quality to improve the user experience. The processor 901 may send a signal to the codec 907 to change the sound quality. The sensor 903 may detect an external input. For example, the sensor 903 may detect a touch input. For example, the sensor 903 may detect a touch pressure. The speaker 905 may send an audio signal. The codec 907 may change the gain of the filter. At least one processor (e.g., Figure 3 The processor 305 of the at least one processor 305 may identify a change in the wearing state based on identifying an external input received through the sensor, such as a change in the amount of speaker port blockage or a change in the volume of the external auditory canal. According to the change in the wearing state, the at least one processor 305 may change the gain according to the frequency of the filter passed through the codec 907. For example, the processor may increase the frequency range of the filter circuit with low gain because the volume of the external auditory canal decreases as the intensity of the touch pressure increases.

[0102] Fig.101 is a flowchart for illustrating the operation of an audio device for controlling an audio signal when performing active noise cancellation (ANC) according to an embodiment. ANC is a function for providing a clean audio signal to a user by removing external noise. The operation of an audio device (e.g., audio device 300 and audio device 501) may be performed by at least one processor (e.g., processor 305).

[0103] In operation 1001, at least one processor (e.g. Figure 3 The processor 305) can output the first audio signal through at least one speaker.

[0104] In operation 1003, at least one processor 305 may receive a noise signal through at least one microphone. The at least one microphone may be a first microphone (e.g., Figure 7 The at least one microphone may be a second microphone (eg, Figure 7 According to an embodiment, the first microphone 701 or the second microphone 703 may be used in an active noise cancellation (ANC) function for removing external noise.

[0105] In operation 1005, at least one processor 305 may generate a tuning signal based on the noise signal. The tuning signal may be generated based on second phase information for eliminating first phase information of the noise signal. External noise may be removed by elimination. For example, the first phase information may be the phase of the noise signal. The second phase information may be the phase of the tuning signal. The phase of the tuning signal may be opposite to the phase of the noise signal.

[0106] At operation 1007, at least one processor 305 may output a second audio signal through at least one speaker, in which the generated tuning signal and the first audio signal are combined. At least one processor 305 may remove external noise through the tuning signal. At least one processor 305 may send the second audio signal to send the first audio signal from which the external noise has been removed.

[0107] In operation 1009, the processor 305 may detect an external input through at least one sensor. The processor 305 may recognize a change in the wearing state of the audio device 501 based on the external input. The at least one sensor may be a sensor for detecting a touch. The at least one sensor may be a sensor for measuring pressure. The at least one sensor may be a sensor for detecting a grip. For example, the processor 305 may detect a touch input through a touch sensor. The processor 305 may recognize a change in the wearing state of the audio device 501 based on the touch input. For example, the processor 305 may detect the pressure of a touch through a pressure sensor. For example, the processor 305 may detect a grip through a grip sensor.

[0108] In operation 1009, the processor 305 may change the gain of the filter circuit in response to an external input. For example, at least one processor 305 may reduce the gain of the filter circuit based on a touch input. In the case of identifying a change in the wearing state based on the touch input, the intensity of the audio signal in the frequency range susceptible to howling may increase. Therefore, at least one processor 305 may prevent howling by reducing the gain of the filter circuit in the frequency range susceptible to howling. The change in the intensity of the audio signal in the wearing state that affects the speaker port may include a change in the amount of blockage, a change in the volume of the external auditory canal, and the like. The processor 305 may determine the change in the wearing state by whether an external input is received through a sensor. The processor 305 may receive an external input through a sensor. The processor 305 may identify a change in the wearing state of the audio device 501 based on receiving a touch input. In the case where an audio signal output from a speaker is input to a first microphone or a second microphone and output again through a speaker, howling may occur. Therefore, in order to prevent howling, the processor 305 may adjust the signal sent to the speaker based on a change in the wearing state. For example, the processor 305 may reduce the gain of the filter circuit in a specific frequency range based on identifying an external input. For example, the filter circuit can be switched from a partial filter circuit in a plurality of partial filter circuits to another partial filter circuit. For example, the processor 305 can activate a partial filter circuit in a plurality of partial filter circuits and deactivate all remaining partial filter circuits. For example, in the filter circuit combination unit, at least one partial filter circuit in a plurality of partial filter circuits can be activated, and at least another partial filter circuit can be deactivated. For example, the filter circuit combination unit can be configured to change the weight of each of the plurality of partial filter circuits. For example, the filter circuit combination unit can be configured to change the weight of each of the plurality of partial filter circuits.

[0109] In operation 1013 , the at least one processor 305 may pass a second audio signal received through the at least one microphone through a filter circuit to generate an output signal.

[0110] In operation 1015, at least one processor 305 may output an output signal through at least one speaker. When the wearing state changes, the processor 305 reduces the gain in the frequency range susceptible to howling to prevent howling of the output signal from occurring. Therefore, even if the amount of speaker port blockage changes or the volume of the external auditory canal changes, howling may not occur.

[0111] Fig.11 is a flowchart for illustrating an operation of an audio device for controlling an audio signal when an ambient sound enabling function or a personal sound amplification product (PSAP) function for hearing ambient sounds is performed according to an embodiment.

[0112] In operation 1101, at least one processor 305 may receive an external signal through at least one microphone. The microphone may be a second microphone (e.g., Figure 7 According to an embodiment, the second microphone 413 may be used in an ambient sound enabling function or a personal sound amplification product (PSAP) function for listening to ambient sounds.

[0113] In operation 1103, at least one processor 305 may generate a tuning signal based on an external signal. According to an embodiment, at least one processor may generate a tuning signal to amplify an external signal received from the second microphone 413. The tuning signal may be generated based on second phase information of first phase information for amplifying the external signal. By amplifying, the wearer may hear the ambient sound, for example, the first phase information may be the phase of the external signal. The second phase information may be the phase of the tuning signal. The phase of the tuning signal may be the same as the phase of the external signal.

[0114] In operation 1105 , the at least one processor 305 may output the generated tuning signal through at least one speaker.

[0115] In operation 1107, at least one processor 305 may detect an external input through at least one sensor. The processor 305 may identify an audio device (eg, Figure 5 The processor 305 may detect a change in the wearing state of the audio device 501. The at least one sensor may be a sensor for detecting a touch. The at least one sensor may be a sensor for measuring a pressure. The at least one sensor may be a sensor for detecting a grip. For example, the processor 305 may detect a touch input through a touch sensor. The processor 305 may recognize a change in the wearing state of the audio device 501 based on the touch input. For example, the processor 305 may detect a pressure of a touch through a pressure sensor. For example, the processor 305 may detect a grip through a grip sensor.

[0116] In operation 1109, at least one processor 305 may change the gain of the filter circuit in response to an external input. For example, at least one processor 305 may reduce the gain of the filter circuit based on a touch input. In the case of identifying a change in the wearing state based on the touch input, the intensity of the audio signal in the frequency range susceptible to howling may increase. Therefore, at least one processor 305 may prevent howling by reducing the gain of the filter circuit in the frequency range susceptible to howling. The change in the intensity of the audio signal in the wearing state that affects the speaker port may include a change in the amount of speaker port blockage, a change in the volume of the external auditory canal, and the like. The processor 305 may determine such a change in the wearing state by whether an external input is received through a sensor. The processor 305 may receive an external input through a sensor. The processor 305 may identify a change in the wearing state of the audio device 501 based on receiving a touch input. In the case where an audio signal output from a speaker is input to a first microphone or a second microphone and output again through a speaker, howling may occur. Therefore, in order to prevent howling, the processor 305 may adjust the signal sent to the speaker based on a change in the wearing state. For example, the processor 305 may reduce the gain of the filter circuit in a specific frequency range based on an external input identifier. For example, the filter circuit can be switched from a partial filter circuit among a plurality of partial filter circuits to another partial filter circuit. For example, the processor 305 can activate a partial filter circuit among a plurality of partial filter circuits and deactivate all remaining partial filter circuits. For example, the filter circuit combination unit can activate at least one partial filter circuit among a plurality of partial filter circuits and deactivate at least another partial filter circuit. For example, the filter circuit combination unit can be configured to change the weight of each of the plurality of partial filter circuits. The filter circuit combination unit can be configured to change the weight of each of the plurality of partial filter circuits.

[0117] In operation 1111 , the at least one processor 305 may pass an audio signal received through at least one microphone through a filter circuit to generate an output signal.

[0118] In operation 1113, at least one processor 305 may output an output signal through at least one speaker. When the wearing state changes, the processor 305 reduces the gain in the frequency range susceptible to howling to prevent howling of the output signal from occurring. Therefore, even if the amount of speaker port blockage changes or the volume of the external auditory canal changes, howling may not occur.

[0119] As described above, according to the embodiment, the audio device may include at least one processor, at least one speaker, at least one microphone, a filter circuit and at least one sensor. At least one processor may be configured to output a first audio signal through at least one speaker. At least one processor may be configured to receive a noise signal through at least one microphone. At least one processor may be configured to generate a tuning signal based on the noise signal. At least one processor may be configured to output a second audio signal through at least one speaker, in which the generated tuning signal and the first audio signal are combined. At least one processor may be configured to detect an external input through at least one sensor. At least one processor may be configured to change the gain of the filter circuit in response to the external input. At least one processor may be configured to pass the second audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. At least one processor may be configured to output an output signal through at least one speaker.

[0120] According to an embodiment, in order to change the gain of the filter circuit, at least one processor can be configured to activate at least one of the multiple partial filter circuits of the filter circuit and deactivate at least another partial filter circuit of the multiple partial filter circuits of the filter circuit.

[0121] According to an embodiment, in order to change the gain of the filter circuit, the at least one processor may be configured to change a weight of each of a plurality of partial filter circuits of the filter circuit.

[0122] According to an embodiment, the audio device may include a housing coupled to the at least one sensor, and a protrusion unit coupled to the housing. The at least one microphone may include a feedback microphone provided on a surface of the housing to which the protrusion unit is coupled.

[0123] According to an embodiment, the audio device may include a housing coupled to the at least one sensor, and a protrusion unit coupled to the housing. The at least one microphone may include a reference microphone disposed on a surface of the housing to which the at least one sensor is coupled.

[0124] According to an embodiment, the at least one sensor may include a touch detection sensor. The external input detected by the touch detection sensor may include a touch input.

[0125] According to an embodiment, in order to generate a tuning signal, at least one processor may be configured to obtain first phase information of a noise signal. At least one processor may be configured to obtain second phase information for canceling the first phase information. At least one processor may be configured to generate a tuning signal based on the second phase information.

[0126] According to an embodiment, in order to change the gain of the filter circuit, the at least one processor may be configured to reduce the gain of frequencies within a specified range for howling cancellation based on pressure of an external input.

[0127] As described above, according to the embodiment, the audio device may include at least one processor, at least one speaker, at least one microphone, a filter circuit and at least one sensor. At least one processor may be configured to receive an external signal through at least one microphone. At least one processor may be configured to generate a tuning signal based on the external signal. At least one processor may be configured to output the generated tuning signal through at least one speaker. At least one processor may be configured to detect an external input through at least one sensor. At least one processor may be configured to change the gain of the filter circuit in response to the external input. At least one processor may be configured to pass an audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. At least one processor may be configured to output an output signal through at least one speaker.

[0128] According to an embodiment, in order to change the gain of the filter circuit, at least one processor may be configured to activate at least one partial filter circuit of the plurality of partial filter circuits of the filter circuit. At least one processor may be configured to deactivate at least another partial filter circuit of the plurality of partial filter circuits of the filter circuit.

[0129] According to an embodiment, in order to change the gain of the filter circuit, the at least one processor may be configured to change a weight of each of a plurality of partial filter circuits of the filter circuit.

[0130] According to an embodiment, the audio device may include a housing coupled to the at least one sensor, and a protrusion unit coupled to the housing. The at least one microphone may include a reference microphone disposed on a surface of the housing to which the at least one sensor is coupled.

[0131] According to an embodiment, the at least one sensor may include a touch detection sensor. The external input detected by the touch detection sensor may include a touch input.

[0132] According to an embodiment, in order to generate a tuning signal, at least one processor may be configured to obtain first phase information of a noise signal. At least one processor may be configured to obtain second phase information for amplifying the first phase information. At least one processor may be configured to generate a tuning signal based on the second phase information.

[0133] According to an embodiment, in order to change the gain of the filter circuit, the at least one processor may be configured to reduce the gain of frequencies within a specified range for howling cancellation based on pressure of an external input.

[0134] As described above, according to an embodiment, the method performed by the audio device may include outputting a first audio signal through at least one speaker. The method may include receiving a noise signal through at least one microphone. The method may include generating a tuning signal based on the noise signal. The method may include outputting a second audio signal through at least one speaker, in which the generated tuning signal and the first audio signal are combined. The method may include detecting an external input through at least one sensor. The method may include changing the gain of a filter circuit in response to the external input. The method may include passing a second audio signal received through at least one microphone through a filter circuit whose gain has been changed to generate an output signal. The method may include outputting the output signal through at least one speaker.

[0135] According to an embodiment, changing the gain of the filter circuit may include activating at least one partial filter circuit of a plurality of partial filter circuits of the filter circuit. Changing the gain of the filter circuit may include deactivating at least another partial filter circuit of a plurality of partial filter circuits of the filter circuit.

[0136] According to an embodiment, changing the gain of the filter circuit may include changing a weight of each of a plurality of partial filter circuits of the filter circuit.

[0137] According to an embodiment, the at least one microphone may include a feedback microphone disposed on a surface of the housing to which the sensor is coupled.

[0138] According to an embodiment, the at least one microphone may include a reference microphone provided on a surface of the housing to which the protrusion unit is coupled.

[0139] According to an embodiment, a non-transitory computer-readable medium is provided. When the non-transitory computer-readable medium is executed by one or more processors, program instructions may be provided, and the program instructions perform the following functions: output a first audio signal through at least one speaker, receive a noise signal through at least one microphone, generate a tuning signal based on the noise signal, output a second audio signal through at least one speaker, the second audio signal is a combination of the generated tuning signal and the first audio signal, detect an external input through at least one sensor, change the gain of a filter circuit in response to the external input, pass the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to generate an output signal, and output the output signal through at least one speaker.

[0140] According to an embodiment, when a non-transitory computer-readable medium is executed by one or more processors, it may be provided with program instructions that perform the following functions: receive an external signal through at least one microphone, generate a tuning signal based on the external signal, output a second audio signal through at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal, detect an external input through at least one sensor, change the gain of a filter circuit in response to the external input, pass the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to generate an output signal, and output the output signal through at least one speaker.

[0141] The electronic device according to various embodiments may be one of various types of electronic devices. For example, the electronic device may include a portable communication device (e.g., a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a household appliance. According to an embodiment of the present disclosure, the electronic device is not limited to those described above.

[0142] It should be understood that the various embodiments of the present disclosure and the terms used therein are not intended to limit the technical features set forth herein to specific embodiments, and include various changes, equivalents or replacements of the corresponding embodiments. With regard to the description of the accompanying drawings, similar reference numerals may be used to refer to similar or related elements. It will be understood that, unless the relevant context clearly indicates otherwise, the singular form of the noun corresponding to the project may include one or more things. As used herein, phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C" and "at least one of A, B or C" etc. may include any one or all possible combinations of the items listed together in the corresponding one of the phrases. As used herein, terms such as "1st" and "2nd", or "first" and "second" may be used to simply distinguish the corresponding component from another component, and do not limit the component in other aspects (e.g., importance or order). It will be understood that if one element (e.g., a first element) is referred to as being “coupled” or “connected” to another element (e.g., a second element), regardless of whether the term “operably” or “communicatively” is used, this means that the element can be coupled to the other element directly (e.g., wired), wirelessly, or via a third element.

[0143] As used in conjunction with various embodiments of the present disclosure, the term "module" may include units implemented in hardware, software, or firmware, and may be used interchangeably with other terms (e.g., "logic," "logic block," "component," or "circuit"). A module may be a single integral component, or its smallest unit or component, adapted to perform one or more functions. For example, depending on the embodiment, a module may be implemented in the form of an application specific integrated circuit (ASIC).

[0144] The various embodiments described herein may be implemented as software (e.g., program 140) that includes one or more instructions stored in a storage medium (e.g., internal memory 136 or external memory 138) readable by a machine (e.g., electronic device 101). For example, a processor (e.g., processor 120) of a machine (e.g., electronic device 101) may call at least one of the one or more instructions stored in the storage medium and execute it with or without one or more other components under the control of the processor. This allows the machine to be operated to perform at least one function according to at least one instruction called. The one or more instructions may include code generated by a compiler or code executed by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Among them, the term "non-transitory" only means that the storage medium is a tangible device and does not include signals (e.g., electromagnetic waves), but the term does not distinguish between the case where data is semi-permanently stored in the storage medium and the case where data is temporarily stored in the storage medium.

[0145] According to the embodiment, the method according to various embodiments of the present disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read-only memory (CD-ROM)), or via an application store (e.g., PlayStore). TM ) online distribution (e.g., downloading or uploading), or directly between two user devices (e.g., smartphones). If distributed online, at least parts of the computer program product may be temporarily generated or at least temporarily stored in a machine-readable storage medium, such as a memory of a manufacturer's server, a server of an application store, or a relay server.

[0146] According to various embodiments, each component (e.g., module or program) of the above-mentioned components may include a single entity or multiple entities, and some of the multiple entities may be individually arranged in different components. According to various embodiments, one or more of the above-mentioned components may be omitted, or one or more other components may be added. Alternatively or additionally, multiple components (e.g., modules or programs) may be integrated into a single component. In this case, according to various embodiments, the integrated component may still perform one or more functions of each of the multiple components in the same or similar manner as performed by a corresponding one of the multiple components before integration. According to various embodiments, the operations performed by a module, a program or another component may be performed sequentially, in parallel, repeatedly or heuristically, or one or more operations may be performed in a different order or one or more operations may be omitted, or one or more other operations may be added.

Claims

1. Audio device, including: at least one processor; at least one speaker; At least one microphone; Filter circuit; as well as at least one sensor, Wherein, the at least one processor is configured as: outputting a first audio signal through the at least one speaker, receiving a noise signal via the at least one microphone, generating a tuning signal based on the noise signal, outputting a second audio signal through the at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal, detecting an external input by the at least one sensor, varying a gain of the filter circuit in response to the external input; passing the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to generate an output signal; and The output signal is output through the at least one speaker.

2. The audio device according to claim 1, wherein To change the gain of the filter circuit, the at least one processor is configured to: At least one partial filter circuit of a plurality of partial filter circuits of the filter circuit is activated, and at least another partial filter circuit of the plurality of partial filter circuits of the filter circuit is deactivated.

3. The audio device according to claim 1, wherein To change the gain of the filter circuit, the at least one processor is configured to: A weight of each of a plurality of partial filter circuits of the filter circuit is varied.

4. The audio device according to claim 1, further comprising: a housing coupled to the at least one sensor; as well as a protruding unit connected to the housing, The at least one microphone includes a feedback microphone, and the feedback microphone is arranged on a surface of the housing to which the protruding unit is coupled.

5. The audio device according to claim 1, further comprising: a housing coupled to the at least one sensor; as well as a protruding unit connected to the housing, The at least one microphone includes a reference microphone, and the reference microphone is arranged on a surface of the housing to which the at least one sensor is coupled.

6. The audio device according to claim 1, in, The at least one sensor includes a touch detection sensor, and The external input detected by the touch detection sensor includes a touch input.

7. The audio device according to claim 1, in, To generate the tuning signal, the at least one processor is configured to: Acquiring first phase information of the noise signal; and acquiring second phase information for cancelling the first phase information, and Wherein, the tuning signal is generated based on the second phase information.

8. The audio device according to claim 1, wherein To change the gain of the filter circuit, the at least one processor is configured to reduce the gain of frequencies within a specified range for howling cancellation based on the pressure of the external input.

9. Audio equipment, including: at least one processor; at least one speaker; At least one microphone; Filter circuit; as well as at least one sensor, Wherein, the at least one processor is configured as: receiving an external signal through the at least one microphone, generating a tuning signal based on the external signal, outputting the generated tuning signal through the at least one speaker, detecting an external input by the at least one sensor, varying a gain of the filter circuit in response to the external input; passing an audio signal received through the at least one microphone through the filter circuit whose gain has been changed to produce an output signal; and The output signal is output through the at least one speaker.

10. A method performed by an audio device, the method comprising: outputting a first audio signal through at least one speaker; receiving a noise signal via at least one microphone, generating a tuning signal based on the noise signal, outputting a second audio signal through the at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal, detecting an external input by at least one sensor, varying a gain of a filter circuit in response to the external input; passing the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to produce an output signal; as well as The output signal is output through the at least one speaker.

11. The method according to claim 10, wherein: Changing the gain of the filter circuit comprises: activating at least one partial filter circuit of a plurality of partial filter circuits of the filter circuit; and At least another partial filter circuit of the plurality of partial filter circuits of the filter circuit is deactivated.

12. The method according to claim 10, wherein: Changing the gain of the filter circuit comprises: A weight of each of a plurality of partial filter circuits of the filter circuit is varied.

13. The method according to claim 10, wherein: The at least one microphone includes a feedback microphone disposed on a surface of the housing to which the sensor is coupled.

14. The method according to claim 10, wherein: The at least one microphone includes a reference microphone disposed on a surface of the housing to which the protrusion unit is coupled.

15. A non-transitory computer readable medium, which, when executed by one or more processors, is provided with program instructions that perform the following functions: outputting a first audio signal through at least one speaker, receiving a noise signal via at least one microphone, generating a tuning signal based on the noise signal, outputting a second audio signal through the at least one speaker, the second audio signal combining the generated tuning signal and the first audio signal, detecting an external input by at least one sensor, varying a gain of a filter circuit in response to the external input; passing the second audio signal received through the at least one microphone through the filter circuit whose gain has been changed to produce an output signal; as well as The output signal is output through the at least one speaker.

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