Abstract: Example techniques may involve multiple calibrations for a playback device. In an example implementation, a playback device plays back audio content according to a first calibration via the one or more audio amplifiers. The playback device detects that an arrangement of one or more listeners relative to the first playback device has changed from a first arrangement to a second arrangement. Based on detection that the arrangement of one or more listeners relative to the first playback device has changed from the first arrangement to the second arrangement, the playback device applies a second calibration to playback by the first playback device.

Abstract: An impedance matching device for matching a characteristic acoustic impedance includes an impedance matching body including a first side and an opposite second side. The impedance matching device is configured to match a characteristic acoustic impedance of a medium contacted on the first side to a characteristic acoustic impedance of a sound transducer contacted on the second side. The impedance matching body includes microstructures which have a structural extent of at most 500 nanometers along at least one spatial direction.

Abstract: The present application discloses a piezoelectric micro electrical mechanical system (MEMS) microphone chip and a piezoelectric MEMS microphone, and relates to the technical field of piezoelectric devices. The piezoelectric MEMS microphone chip includes at least one substrate frame and at least one plurality of sound receiving beams arranged on the substrate frame. Each of the sound receiving beams includes a connecting beam and a cantilever beam. The connecting beam and the cantilever beam are staggered on a circumference. One ends of the plurality of sound receiving beams that face a geometric center of the a circumference are fixedly connected to one another in a center defined by the substrate frame, and one end of the connecting beam that is away from the geometric center is fixedly connected to the substrate frame.

Abstract: The present invention provides a headphone, comprising: a casing in which a hole portion leading to the inside and outside is formed; a diaphragm; a support for supporting the diaphragm; and an air flow path for air taken from the outside of the casing to the inside through the hole portion, wherein a plurality of the air flow paths are provided, and extension directions of axes set on an open end surface on one side of the air flow paths intersect.

Abstract: There is provided a method for controlling bass reproduction properties of a multichannel audio system, wherein the audio system has inputs for at least two audio input signals and includes a set of loudspeakers, including at least one bass-capable loudspeaker and at least two high-range loudspeakers, each loudspeaker being associated with a loudspeaker channel. The method includes obtaining impulse responses or transfer functions that represent the sound reproduction properties of each loudspeaker channel at a number of measurement or control positions. The method also includes tuning, when the audio system includes more than one bass-capable loudspeaker, loudspeaker channels of at least two bass loudspeakers to each other so that their sum impulse response has minimum spatial variability, and/or controlling high-range loudspeaker speaker channels to be in-phase with each other and/or with bass-capable loudspeaker channel in a crossover frequency band.

Abstract: A microphone bed for receiving a microphone. The microphone bed including a first compressible portion and first and second non-compressible portions. The first compressible portion is formed to accommodate a first end of the microphone. The first non-compressible portion has the compressible portion coupled thereto, the non-compressible portion having a length that is over half a length of the microphone. The second non-compressible portion is coupled to the first non-compressible portion, which together form a cavity therebetween, the second non-compressible portion having a floor. There is a weighted feature extending upward from the floor of the second non-compressible portion.

Abstract: In a stereo encoding method, a channel combination encoding solution of a current frame is first obtained, and then a quantized channel combination ratio factor of the current frame and an encoding index of the quantized channel combination ratio factor are obtained based on the obtained channel combination encoding solution, so that an obtained primary channel signal and secondary channel signal of the current frame meet a characteristic of the current frame.

Abstract: Hearing aids having example antennas tuned to transmit and receive signals having a frequency greater than or equal to 2.4 GHz are described. The antenna includes a first segment and a second segment. The first segment is configured to fit inside a housing of the hearing aid and to be within the ear canal when the hearing aid is inserted into an ear of a wearer. The second segment is configured to be within the housing and disposed near a side of the housing facing toward an outside of the ear canal when the hearing aid is inserted into the ear of the wearer.

Abstract: Examples of the disclosure describe systems and methods for estimating acoustic properties of an environment. In an example method, a first audio signal is received via a microphone of a wearable head device. An envelope of the first audio signal is determined, and a first reverberation time is estimated based on the envelope of the first audio signal. A difference between the first reverberation time and a second reverberation time is determined. A change in the environment is determined based on the difference between the first reverberation time and the second reverberation time. A second audio signal is presented via a speaker of a wearable head device, wherein the second audio signal is based on the second reverberation time.

Abstract: Speaker systems are provided, particularly for mounting in off-road vehicles, ATVs, UTVs, watercraft and motorcycles. The speaker systems may include a linear array of speakers and a housing encasing a backside thereof. In some cases, the speaker systems include a pipe-mounting clamp coupled to the housing for mounting the speaker system to a surface. In addition or alternatively, the speaker systems may include mounting brackets arranged along opposing lateral sides of the housing for mounting the speaker system to a surface. In any case, the speaker systems may include a power cord extending from one of the opposing lateral sides of the housing in some embodiments.

Abstract: A communication headset includes an earcup, a headband, and a microphone boom assembly. The microphone boom assembly includes a microphone boom, a gear assembly disposed on the earcup and supporting the microphone. The gear assembly enables a rotation of the microphone boom.

Abstract: An in-ear earphone, including a casing, a speaker, and an attenuation guide, is provided. The casing includes a sound outlet and a first through hole. An inside of the casing has a first accommodating space. The speaker is disposed in the first accommodating space. The casing defines a front cavity and a rear cavity by the speaker. The attenuation guide is formed in the casing and includes at least a first attenuation channel and a second attenuation channel. The first attenuation channel has a first inlet and a first outlet. The first inlet is connected to the first through hole. The second attenuation channel has a second inlet and a second outlet. The second inlet, the first outlet, and the rear cavity are acoustically connected, and the second outlet is connected to the front cavity.

Abstract: The improved active noise cancellation system for forced air heating or cooling systems onboard aircraft employs a duct having a proximal end coupled to the fan unit to entrain the airflow stream in the direction of a distal end of the duct. A reference sensor is positioned within the proximal end of the duct. A means is provided for injecting an audio frequency control signal into the airflow stream in a manner that does not substantially impede the airflow stream. An error sensor is positioned at the distal end of the duct where it is responsive to sounds carried by the airflow stream, including the audio frequency control signal. An electronic circuit coupled to the reference sensor and to the error sensor supplies a noise abating control signal to energize the control transducer and thereby substantially reduce at least one noise harmonic of the fan unit through destructive interference.

Abstract: Aheadphone configured to emit a fractal-polarized sound field is provided. The headphone comprises a sound-emitting membrane, an acoustic oscillator, and an ear pad. The sound-emitting membrane comprises a paper-based composite material layer, a metal layer, and a coating layer. The paper-based composite material layer has a front surface and a rear surface, with the front surface facing a user ear. The metal layer is provided on the front surface of the paper-based composite material layer and configured to reproduce HF acoustic oscillations. The coating layer is provided on the metal layer and has one or more slots through which the metal layer is visible. The coating layer is made of a material incapable of reproducing the HF acoustic oscillations. The acoustic oscillator generating the acoustic oscillations is attached to the rear surface of the paper-based composite material layer. The ear pad is configured to cover the coating layer.

Abstract: A speaker device is used while being attached to a helmet, and includes a speaker unit that outputs a sound, a speaker housing that includes a back wall portion covering the speaker unit from a back side, and in which a space between a back surface of the speaker unit and the back wall portion is formed as an output space for the sound output from the back surface of the speaker unit, and a duct whose internal space is communicated with the output space and that guides, to an outside of the helmet, the sound output to the output space, in which a distance between the back surface of the speaker unit and the back wall portion is smaller than a distance of the internal space of the duct in a direction in which the duct guides the sound.

Abstract: A method or apparatus provides binaural sound that originates to a person at a location inside a field of view (FOV) provided to the person by an electronic device. The electronic device determines when the location of the binaural sound moves outside the FOV and assists the person in determining the location of the binaural sound. A display of the electronic device displays a visual indication that shows a direction to the location of the binaural sound outside the FOV.

Abstract: A microphone includes an amplifier coupled to an input node of the microphone; a shock detector coupled to the input node of the microphone; and a recovery circuit having an input coupled to an output of the shock detector, and an output coupled to the input of the microphone.

Abstract: A skin audible watch for orientation identification includes a dial (1) and a strap (2). A plurality of sound collection modules (3) are arranged along a circumference of the dial (1), and the sound collection modules (3) are sequentially connected with a digital filter (4), an analog-to-digital converter (5), a single-chip microcomputer (6), and a row and column drive module (7); the single-chip microcomputer (6) is also connected with vibration motors (8) and a gyroscope (9); a number of the vibration motors corresponds to a number of orientations; the digital filter (4), analog-to-digital converter, single-chip microcomputer, row and column drive module, the vibration motors and the gyroscope are located inside the dial; the row and column drive module is connected with a current contact pin (12), and a free end of the current contact pin extends out of a surface of the vibration motors.

Abstract: A microphone assembly includes an acoustic transducer configured to generate an analog signal in response to pressure changes sensed by the acoustic transducer. The analog signal includes frequency components below a threshold frequency. The microphone assembly also includes an integrated circuit electrically coupled to the acoustic transducer and configured to determine a characteristic of frequency components below the threshold frequency, determine whether the characteristic of the frequency components corresponds to a fall event, and generate an output signal in response to a determination that the characteristic of the frequency components corresponds to the fall event. The microphone assembly also includes a housing having an external device interface with electrical contacts. The acoustic transducer and the integrated circuit are disposed within the housing. The integrated circuit is electrically coupled to contacts of the external device interface.

Abstract: The present disclosure relates to an acoustic output apparatus. The acoustic output apparatus may include an earphone core including at least one acoustic driver for outputting sound though one or more sound guiding holes set on the acoustic output apparatus, a controller configured to cause the at least one acoustic driver to output sound, a power source assembly configured to provide electrical power to the earphone core, the one or more sensors, and the controller, and an interactive control component configured to allow an interaction between a user and the acoustic output apparatus.