Abstract: Methods and systems for modification of electronic system operation based on acoustic ambience classification are presented. In an example method, at least one audio signal present in a physical environment of a user is detected. The at least one audio signal is analyzed to extract at least one audio feature from the audio signal. The audio signal is classified based on the audio feature to produce at least one classification of the audio signal. Operation of an electronic system interacting with the user in the physical environment is modified based on the classification of the audio signal.

Abstract: A device is configured to (i) receive media content from a media source, (ii) generate a first series of frames including first portions of the media content and first playback timing information, (iii) generate a second series of frames including second portions of the media content and second playback timing information, (iv) transmit the first series of frames to a first playback device in a synchrony group for playback of the first portions of the media content in accordance with the first playback timing information, and (v) transmit the second series of frames to a second playback device in the synchrony group for playback of the second portions of the media content in accordance with the second playback timing information such that the media content is played back in synchrony by the synchrony group.

Abstract: In one example, a zone player may include a network interface, at least one processor, a non-transitory computer-readable medium, and program instructions stored on the non-transitory computer-readable medium that may be executable by the at least one processor such that the zone player is configured to receive an instruction to change a volume setting of the zone player to a requested volume level; in response to receiving the instruction to change the volume setting of the zone player to the requested volume level, adjust the volume setting of the zone player to an adapted volume level that is lower than the requested volume level; and after adjusting the volume setting of the zone player to the adapted volume level, send an indication that the volume setting of the zone player has been adjusted to the requested volume level rather than the adapted volume level.

Abstract: An audio processing device includes a signal processing circuit, a power switch circuit, a power amplifier and a detection circuit. The signal processing circuit is configured to process an audio input to generate an audio signal. The power switch circuit is configured to generate an operating voltage. The power amplifier is coupled with the signal processing circuit and the power switch circuit, and configured to drive a load circuit by the operating voltage according to the audio signal. The detection circuit is coupled with the signal processing circuit and the power switch circuit, configured to obtain a volume value from the audio signal and compare the volume value with a first volume threshold to generate a comparison result, and configured to control, according to the comparison result, the power switch circuit to set the operating voltage to have a corresponding one of multiple voltage levels.

Abstract: Apparatus for protection of the ear and ear canal, and related methods of use and operation. In one embodiment, the apparatus includes a selectively actuated valve which permits a varying or modulated size of aperture to be created by the wearer while the apparatus is in use, so as to accommodate varying functions, such as complete occlusion (e.g., for use in swimming or other aquatic activities such that water can be completely excluded) or partial occlusion (e.g., such that sounds can be heard by the wearer, whether in air or under water). In one implementation, the apparatus is retained within the ear canal of the wearer by virtue of the apparatus' shape and coordination with one or more natural features or contours of the anatomy in the ear region, without having to be inserted more than superficially into the outer portion of the ear canal.

Abstract: A loudspeaker system is provided herein comprising: a digital transmitter adapted to store, retrieve, and transmit digital messages over a network cable using an audio over internet protocol (AoIP), and wherein the transmitted digital messages are individually addressable using an IP address, and wherein the transmitted digital messages contain digital audio messages and digital command and control messages; an endpoint enclosure adapted to have a unique IP address pre-assigned to it such that the endpoint enclosure is adapted to receive the transmitted digital messages addressed to it and extract the digital audio messages and the digital command and control messages from the transmitted and received digital messages, and wherein the endpoint enclosure comprises additional circuitry adapted to extract the digital audio messages from the received digital messages and power from the network cable, and generate an electrical audio signal from the extracted digital audio messages; an “N” position switch adapted

Abstract: A display panel and a display apparatus. The display panel includes a first transparent display region, at least one second transparent display region and a main display region. Light transmittance of the first transparent display region is greater than light transmittance of the at least one second transparent display region, and the light transmittance of the at least one second transparent display region is greater than light transmittance of the main display region. Light passes through the first transparent display region and enters a first photosensitive element located on a back of the display panel, light passes through the at least one second transparent display region and enters a second photosensitive element located on the back of the display panel, and the first photosensitive element requires a greater brightness of light than the second photosensitive element.

Abstract: A wearable electronic device includes: an input module configured to receive a user manipulation for changing a configuration setting value of a main electronic device; and a communication module configured to transmit a control signal for changing a configuration setting value to the main electronic device.

Abstract: Embodiments are provided for intelligently activating an amplifier in a playback device based on proximity detection. The playback device may be in a quasi-idle state when the playback device is not rendering media content. The quasi-idle state of the playback device may involve an amplifier in the playback device being inactive, while some other components or modules of the playback devices remain active. The playback device may include a proximity sensor configured to detect movement relative to the playback device. If movement is detected indicating that a user input to cause the playback device to render media content is anticipated, the amplifier may be pre-emptively activated such that the playback device enters an active state from the quasi-idle state. In some cases, the playback device may send a message to one or more other playback devices to cause the other playback devices to enter an active state.

Abstract: An electronic device includes a memory storing a plurality of fingerprint reference data files and one or more sensors identifying whether a mechanical support condition of the electronic device is a hand supported condition or a surface supported condition. A fingerprint sensor receives fingerprint data while the electronic device is in the mechanical support condition. One or more processors select a prioritized fingerprint data reference file from the plurality of fingerprint reference data files as a function of the mechanical support condition and authenticate an authorized user of the electronic device by comparing the fingerprint data to the prioritized fingerprint data reference file before comparing the fingerprint data to any other fingerprint reference data files of the plurality of fingerprint reference data files. The prioritized fingerprint reference data file can also be selected as a function of a geometric form factor of the electronic device.

Abstract: An in-vehicle independent sound field system and control system based on mini-speakers are provided. The system includes a mini-speaker array installed in front of a user and a mini-speaker installed near the user's ear. Each mini-speaker is provided with a coupling rear cavity, and the mini-speaker near the user's ear is provided with a sound guide front cavity. A controller is provided to control the mini-speaker array to perform an intermediate-and-high frequency directional replay, and control the mini-speakers near the user's ear to perform low-frequency replay and autonomous counterbalance, to solve the problem that a speaker array cannot be installed with a traditional in-vehicle speaker size and that a low-frequency effect is bad when merely using a speaker array to control sound direction, Besides, when different sources are being played, they rarely interfere with each other, thereby improving personalized requirements for sound and user experience of users in a vehicle.

Abstract: Systems, devices, and methods for assistive listening that uses sound waves for devices pairing is described herein. An assistive listening system may use sound waves to pair mobile devices acting as assistive listening devices with stationary devices. To establish a communication link (e.g., pair the two devices), a mobile device may exchange a plurality of signals over a plurality of sound waves with a stationary device. The plurality of sound waves may operate in a set of frequencies above a frequency range detectable by a human ear (e.g., above 20 kHz). After the pairing procedure over the sound waves is complete, the assistive listening system may use electromagnetic waves to pair the mobile devices with the stationary devices over a wireless access technology, such as Digital Enhanced Cordless Telecommunications (DECT).

Abstract: A head restraint assembly is provided having a head restraint with a forward contact surface. At least one loudspeaker driver is embedded in the head restraint and offset rearward from the forward contact surface. A waveguide extends from the loudspeaker driver toward the forward contact surface and is configured to direct a sound output from the loudspeaker driver at a listening direction being different than a central axis of radiation of the loudspeaker driver.

Abstract: The technology described in this document can be embodied in a headrest for a vehicle-seat, the headrest including a first acoustic assembly and a second acoustic assembly. The first acoustic assembly includes a first set of one or more acoustic transducers, and is configured to radiate acoustic energy from a first portion of the headrest in a first radiation pattern. The second acoustic assembly includes a second set of one or more acoustic transducers, and is configured to radiate acoustic energy from a second portion of the headrest in a second radiation pattern. The first acoustic assembly and the second acoustic assembly are configured such that the first radiation pattern and the second radiation pattern are substantially different from one another, and generate an asymmetric radiation pattern for the headrest.

Abstract: A speaker system uses destructive wave interference to generate “dead spots” with respect to an audio presentation. The signal for the dead spot generating device can be an inverted signal generated using the audio signal. In one embodiment, the inverted signal is generated using the audio signal, an indication of loudness at one or more active speakers, and a determination of the characteristics of the sound path from the one or more active speakers (including delay and attenuation).

Abstract: A system and method includes presentation of a mixed-reality environment to a user, presentation of a first audio control to the user within the mixed-reality environment, detection of a manipulation by the user of the first audio control within the mixed-reality environment, determination of a first value of an audio-related parameter associated with speech intelligibility based on the manipulation, determination of two or more audio processing parameter values associated with speech intelligibility based on the first value, reception of first speech audio signals, application of audio processing to the first speech audio signals based on the determined two or more audio processing parameter values to generate second speech audio signals, and transmission of the second speech audio signals to a loudspeaker system for playback to the user.

Abstract: One or more computing devices, systems, and/or methods for controlling a volume level of a device are provided. For example, a first button corresponding to increasing a volume level of a device may be selected, and the volume level may be increased by a first amount (e.g., 10%). A second button corresponding to decreasing the volume level of the device may be selected. If the second button is determined to have been selected within a threshold period of time after the selection of the first button, the volume level may be decreased by a second amount (e.g., 5%). If the second button is determined to have not been selected within the threshold period of time after the selection of the first button, the volume level may be decreased by the first amount (e.g., 10%).

Abstract: An indicator identifying a force intensity of a touch input provided on a touch input surface is received. It is determined that the touch input is associated with an audio volume control. An audio volume is controlled based at least in part on the indicator identifying the force intensity of the touch input.

Abstract: There is provided a system (100) comprising an audio streaming device (102) having an audio streaming device receiver (104) arranged for receiving a first audio signal (106) comprising a first audio content and a second audio signal (108) comprising a second audio content, the system furthermore comprising a memory device (110) arranged for storing a user defined setting (112), a processor (114) arranged for providing an output audio signal (116), said output audio signal comprising a combination of the first audio content, and the second audio content, wherein the output audio signal comprises a ratio of a level of the first audio content and a level of the second audio content, and the ratio is determined based on the user defined setting (112), and wherein the system is further comprising a system transmitter (118) arranged for wirelessly transmitting the output audio signal (116).

Abstract: An apparatus and method are provided for controlling an operation of an electronic device by using a fingerprint image in the electronic device. The electronic device includes a display and a processor configured to detect a fingerprint image corresponding to a user input; determine an input direction of the user input based on the fingerprint image; determine a motion direction of the user input based on the input direction of the user input in response to a motion of the user input; and execute a first function corresponding to the motion direction of the user input.

Abstract: Various systems and methods are disclosed herein to increase the quality of the sound and intelligibility of speech delivered to a user by combining electric audio signals from more than one hearing assistance device that incorporates an active signal enhancement system. The method includes receiving electric audio signals at a first hearing assistance device, and sending electric audio signals to a second hearing assistance device. The electric audio signal is encoded as a replacement for input to an microphone channel located at the second hearing assistance device. The electric audio signals from the microphone located at the first hearing assistance device and the microphone located at the second hearing assistance device are combined. The combined electric audio signals are processed through a digital signal processor in the first hearing assistance device to enhance the amplitude of the desired signal via constructive interference.

Abstract: Provided is a sound output apparatus which realizes listening characteristics of the ambient sound even in a wearing state, which are equivalent to those in a non-wearing state, and outputs good acoustic information at the same time. A sound output apparatus 100 includes a sound generation unit 110 which generates sound, a sound guiding unit 120 which takes in, from one end 121, the sound generated from the sound generation unit 110, and a ring-shaped holding unit 130 which holds the sound guiding unit 120 in the vicinity of the other end 122. The sound output apparatus 100 is worn on the pinna by locking the holding unit 130 to the intertragic notch, and the holding unit 130 supports the vicinity of the other end 122 of the sound guiding unit 120 so that a sound output hole of the other end 122 of the sound guiding unit 120 is positioned to face the interior side of the ear canal.

Abstract: An Auto Setup Program (“ASP”) may be implemented in the sound system of a vehicle to accomplish the goal of a dramatically improved audio quality achievable in any vehicle, regardless of the speaker components and head-unit utilized. The ASP performs automated time alignment measurements and equalizer processes using an external microphone. The ASP eliminates the need for expensive and time consuming professional tuning operations. The on-board ASP can be run multiple times as desired. For example, the ASP can be executed after changes to the system, such as upgrading speakers.

Abstract: A method for providing disparate audio broadcasts for a content item of a content sharing platform is disclosed. The method includes providing, via a user interface (UI) comprising at least a video portion of a content item, selectable links to a plurality of audio commentaries corresponding to the content item, wherein the plurality of audio commentaries are recorded by different users separately from an original audio recording of the content item, receiving an indication of a selection of an audio commentary from the plurality of audio commentaries, the selection received from the computing device, synchronizing the selected audio commentary with the video portion of the content item, decoupling environmental noise from the original audio recording, and providing the synchronized audio commentary and the decoupled environmental noise, in lieu of the original audio recording, in conjunction with the video portion to the computing device of the viewer via the UI.

Abstract: A mixer includes a storage portion, a reception portion, a user-definition-scene-memory setting portion, a setting changing portion, a storage processing portion, and a recall processing portion. The reception portion receives specification of several parameters among a plurality of parameters. The storage portion stores setting values of the plurality of parameters. The user-definition-scene-memory setting portion stores the several parameters, received by the reception portion, in the storage portion for every scene as a user-definition-scene-memory. The setting changing portion receives an operation of changing current setting of the plurality of parameters. The storage processing portion stores setting values of the several parameters, changed in the setting changing portion, in the current data storage portion.

Abstract: A method comprising: automatically applying a selection criterion or criteria to a sound object; if the sound object satisfies the selection criterion or criteria then performing one of correct or incorrect rendering of the sound object; and if the sound object does not satisfy the selection criterion or criteria then performing the other of correct or incorrect rendering of the sound object, wherein correct rendering of the sound object comprises at least rendering the sound object at a correct position within a rendered sound scene compared to a recorded sound scene and wherein incorrect rendering of the sound object comprises at least rendering of the sound object at an incorrect position in a rendered sound scene compared to a recorded sound scene.

Abstract: An exemplary system directs a camera included within a mobile device to capture a video feed, directs the mobile device to display the video feed within a display screen of the mobile device, and identifies a plurality of adjacent pixel blocks within the display screen that have signal characteristics that uniformly vary by more than a threshold amount over a predetermined time period. Based on the uniformly varying signal characteristics, the system determines that a pixel region constituted by the pixel blocks corresponds to a position of a display device within a field of view of the camera. The system identifies a media content instance being displayed by the display device, identifies augmented reality content associated with the media content instance, and directs the mobile device to display the augmented reality content within the pixel region of the display screen.

Abstract: A cable assembly for electronic devices such as cellular telephones and music devices is disclosed. The cable assembly can comprise either one or two earpieces, each of which is configured to be received into the concha of a user's ear. The earpiece(s) can be configured so as to be held in place by at least one anatomical structure of the concha. A speaker can be in acoustic communication with each earpiece. A cable can be configured to communicate a signal representative of sound from the electronic device to each earpiece. A microphone can be permanently attached or removably attachable to the cable to facilitate use with a cellular telephone. The cable assembly can facilitate hands free operation of a cellular telephone and can facilitate listening to a music device. Other implementations and related methods are also disclosed.

Abstract: A system and method for tuning an audio system based on a seat position. The system senses and measures any change in seat position from a default seat position and adjusts a set of modified tuning parameters to be applied to the audio system based on the modified seat position. The modified tuning parameters may be mapped to a set of tuning parameters depending on the sensed and measured seat position. Alternatively, the modified tuning parameters may be set somewhere between a minimum set of tuning parameters and a maximum set of tuning parameters based on the sensed and measured seat position.

Abstract: One or more computing devices, systems, and/or methods for controlling a volume level of a device are provided. For example, a first button corresponding to increasing a volume level of a device may be selected, and the volume level may be increased by a first amount (e.g., 10%). A second button corresponding to decreasing the volume level of the device may be selected. If the second button is determined to have been selected within a threshold period of time after the selection of the first button, the volume level may be decreased by a second amount (e.g., 5%). If the second button is determined to have not been selected within the threshold period of time after the selection of the first button, the volume level may be decreased by the first amount (e.g., 10%).

Abstract: A method is provided for adapting an applied volume gain in an audio amplifier controlling at least one loudspeaker of an enclosure according to a desired volume gain selected by a user on a scale increased by a maximum desired volume gain, including determining effective intensity applied to the loudspeaker, calculating maximum volume gain from the desired volume gain, an effective intensity applied to the at least one loudspeaker, thermal characteristics of the loudspeaker, and the maximum desired volume gain, then calculating a variable applied volume gain according to an increasing monotonic function providing a variable applied volume gain according to the desired volume gain such that the image of the maximum desired volume gain by the monotonic function is equal to the maximum volume gain, and applying to the amplifier as applied volume gain, the minimum of the desired volume gain and the variable applied volume gain.

Abstract: Controlling an audio volume is disclosed. An indicator identifying a force intensity of a touch input provided on a touch input surface is received. It is determined that the touch input is associated with an audio volume control. The audio volume is controlled based at least in part on the indicator identifying the force intensity of the touch input.

Abstract: A system and method for applying a set of road noise cancellation parameters to a road noise cancellation system in a vehicle traveling from a first road surface type to a second road surface type, the set being associated with a vehicle type, a tire type, a road surface type, or a vehicle location. The system and method collects and compares data with the set of road noise cancellation parameters in a database to identify when the vehicle has traveled from a first road surface type to a second road surface type and, upon identifying the vehicle has traveled from a first road surface type to a second road surface type, applies the adjusted set of road noise cancellation parameters in the database that optimize the road noise cancellation system for the second road surface type.

Abstract: A method for dynamic modification of audio content. An audio content theme includes audio information relating to at least one theme variation. The method includes the steps of: receiving an intensity parameter indicative of an amount of audio information being played and a variation parameter indicative of at least one theme variation of the audio information being played; modifying, based on said intensity parameter, the amount of audio information being played, and, based on said variation parameter, the at least one theme variation of the audio information being played. Also described is a computer program configured to be executed on a computer device for dynamic modification of an audio content theme.

Abstract: An adapter apparatus for an earphone accessory is provided. The adapter apparatus includes an earphone jack, a connection interface, a pre-amplifier and a device adapter circuit. The earphone jack is suitable for a plug of the earphone accessory to plug in. The connection interface is suitable for being electrically connected with a portable device. The pre-amplifier is electrically connected to the earphone jack to receive an earphone control signal of the earphone accessory and to provide an amplified earphone control signal. The device adapter circuit is electrically connected to the pre-amplifier and the connection interface to receive the amplified earphone control signal of the earphone accessory and provide a device control signal to the portable device via the connection interface.

Abstract: This disclosure falls into the field of audio coding, in particular it is related to the field of spatial audio coding, where the audio information is represented by multiple audio objects including at least one dialog object. In particular the disclosure provides a method and apparatus for enhancing dialog in a decoder in an audio system. Furthermore, this disclosure provides a method and apparatus for encoding such audio objects for allowing dialog to be enhanced by the decoder in the audio system.

Abstract: Mixture model based soft-clipping detection includes receiving input audio samples, generating soft-clipping information indicating whether the input audio samples include soft-clipping distortion, and outputting the soft-clipping information. Generating the soft-clipping information includes fitting a mixture model to the input audio samples, wherein fitting the mixture model to the input audio samples includes generating a fitted mixture model, such that the fitted mixture model has fitted parameters, and evaluating a soft-clipping distortion metric based on the parameters of the fitted mixture model, wherein evaluating the soft-clipping distortion metric includes identifying a soft-clipping distortion value.

Abstract: The present disclosure relates to electronic devices and methods for controlling power supplied to earphones. According to an embodiment of the present disclosure, a method for controlling power by an electronic device may comprise applying a power to an earphone corresponding to sensing a coupling of the earphone, adjusting the power applied to the earphone corresponding to sensing an input through a button of an earphone, and applying the adjusted power.

Abstract: Controlling an audio volume is disclosed. An indicator identifying a force intensity of a touch input provided on a touch input surface is received. It is determined that the touch input is associated with an audio volume control. The audio volume is controlled based at least in part on the indicator identifying the force intensity of the touch input.

Abstract: Disclosed herein are methods and systems for intelligent dual-channel volume adjustment. One embodiment takes the form of a dual-watch mobile radio that includes a first receiver, a second receiver, an audio output port, a one-dimensional (1-D) volume control, and a controller programmed to carry out a set of functions. The set of functions includes receiving first and second audio signals from the first and second receivers, respectively, and generating first and second amplified audio signals at least in part by applying first and second signal gains to the first and second audio signals, respectively, as well as outputting the first and second amplified audio signals via the audio output port. The set of functions also includes receiving volume-control commands from the 1-D volume control, and responsively adjusting the first and second signal gains at least in part by applying a gain function to the first and second signal gains.

Abstract: One or more computing devices, systems, and/or methods for controlling a volume level of a device are provided. For example, a first button corresponding to increasing a volume level of a device may be selected, and the volume level may be increased by a first amount (e.g., 10%). A second button corresponding to decreasing the volume level of the device may be selected. If the second button is determined to have been selected within a threshold period of time after the selection of the first button, the volume level may be decreased by a second amount (e.g., 5%). If the second button is determined to have not been selected within the threshold period of time after the selection of the first button, the volume level may be decreased by the first amount (e.g., 10%).

Abstract: A hearing aid communication system and a hearing aid communication method thereof are disclosed. The hearing aid communication method includes the steps of: determining whether a sound-providing apparatus is providing a sound signal; when the sound-providing apparatus is providing a sound signal, establishing a connection with a hearing aid; receiving the sound signal from the sound-providing apparatus for transmission to the hearing aid; and when the sound-providing apparatus stops providing the sound signal, breaking the connection with the hearing aid.

Abstract: The present disclosure relates to a method and an apparatus for automatically controlling a gain in an electronic device based on a sensitivity of microphone. The method according to an embodiment of the present disclosure includes outputting a reference audio to a speaker and obtaining a sound signal output by the speaker through a microphone, comparing a parameter of the obtained sound signal with a stored parameter, and adjusting a gain of the microphone based on a result of the comparing.

Abstract: There is provided a media device for use in a system including a plurality of speakers. The media device includes a memory configured to store a software application, and a processor configured to execute the software application to transmit one or more audio calibration signals to the plurality of speakers for emission by the plurality of speakers, receive, from a user device, information relating to a detection of the one or more audio calibration signals by the user device, and analyze the information received from the user device to determine a position of the user device.

Abstract: A method for providing audio content to a user device in a movie theater includes the steps of personalizing the audio content for the user device based on an identifier and providing the personalized audio content to the user device. In some embodiments, the identifier is based on demographic information about the user. According to some embodiments, the personalized audio content accompanies additional content that is not provided by the user device. In some embodiments, the personalized audio content accompanies a movie.

Abstract: The present invention provides a method and an apparatus for exchanging control functions of volume control units, and a terminal, which relate to the field of communications technologies and can make it more convenient for a user to adjust volume. The method includes: obtaining current placement status information of the terminal, where the placement status information is used to indicate a current placement status of the terminal, and at least two volume control units are disposed in the terminal; and exchanging volume control functions of the at least two volume control units when the current placement status of the terminal deviates from a normal placement status of the terminal, where the at least two volume control units include a volume control unit whose volume control function is to control volume to increase and a volume control unit whose volume control function is to control volume to decrease.

Abstract: To realize a change in a volume that does not give a user a feeling of strangeness even when a great processing load is put on a volume determining unit. A volume controller performs a process for determining a new volume of an audio signal based on an alternate pulse interval that is based on a counting time and the number of pulses counted by a counting section within the counting time and a current volume stored in a storage section, and storing the determined new volume as the current volume in the storage section, the same number of times as the number of pulses counted by the counting section every counting time, and outputs last information stored as the current volume in the storage section to an electronic volume.

Abstract: Embodiments that relate to energy efficient gesture input on a surface are disclosed. One disclosed embodiment provides a hand-worn device that may include a microphone configured to capture an audio input and generate an audio signal, an accelerometer configured to capture a motion input and generate an accelerometer signal, and a controller comprising a processor and memory. The controller may be configured to detect a wake-up motion input based on the accelerometer signal. The controller may wake from a low-power sleep mode in which the accelerometer is turned on and the microphone is turned off and enter a user interaction interpretation mode in which the microphone is turned on. Then, the controller may contemporaneously receive the audio signal and the accelerometer signal and decode strokes. Finally, the controller may detect a period of inactivity based on the audio signal and return to the low-power sleep mode.

Abstract: An amplifier including a first gain level is provided. An analog input is provided to the amplifier. An analog output from the amplifier is converted to a digital output. The digital output is analyzed to detect a level of the analog output exceeding a threshold. A second gain level of the amplifier is set lower than the first gain level. An interface is provided to adjust the threshold. A signature of the analog output is identified. A library comprising a plurality of signatures is provided including the signature of the analog output. The signature of the analog output is compared to the plurality of signatures to determine when to reset the first gain level of the amplifier. The level of the digital signal is monitored to determine when to reset the first gain level of the amplifier. The first and second gain levels are set using a digital signal processor.

Abstract: A sound volume adjuster includes: a storage which stores a first value of a volume setting value and an allowable maximum change amount; a communication interface which receives a change request indicating a second value of the volume setting value; a comparison device which, when a change amount of the volume setting value between the first value and the second value exceeds the allowable maximum change amount, determines that the change request is an excessive request; and a volume controller which, when the comparison device determines that the change request is the excessive request: changes the first value stored in the storage by a change amount which is equal to or smaller than the allowable maximum change amount to set a third value of the volume setting value; and adjusts a sound volume by the third value.