Abstract: Some methods involve receiving an input audio signal that includes N input audio channels, the input audio signal representing a first soundfield format having a first soundfield format resolution, N being an integer ?2. A first decorrelation process may be applied to two or more of the input audio channels to produce a first set of decorrelated channels, the first decorrelation process maintaining an inter-channel correlation of the set of input audio channels. A first modulation process may be applied to the first set of decorrelated channels to produce a first set of decorrelated and modulated output channels. The first set of decorrelated and modulated output channels may be combined with two or more undecorrelated output channels to produce an output audio signal that includes O output audio channels representing a second and relatively higher-resolution soundfield format than the first soundfield format, O being an integer ?3.

Abstract: An apparatus including an input configured to receive at least one first audio signal from a first apparatus; an input configured to receive at least one second audio signal from a second apparatus; a distance detector configured to determine a distance between the first and the second apparatus; and a level control generator configured to generate a level control for mixing the at least one first audio signal and the at least one second audio signal based on the distance between the first and the second apparatus.

Abstract: A head-mounted display (HMD) includes a strap arm that transmits audio. The HMD includes a front rigid body and a strap arm. The strap arm includes a body portion defining a boss having an aperture that rotatably connects the strap arm to the front rigid body. The body portion defines an audio passage to transmit sound and an audio port to output the sound. The audio passage is defined along the body portion between the aperture of the boss and the audio port. A speaker is positioned, such as within the aperture, to emit the sound through the audio passage and to the audio port. The strap arm can further include a back volume unit that enhances the sound transmitted through the audio passage.

Abstract: The disclosure relates to an audio signal processing apparatus for filtering a left channel input audio signal (L) and a right channel input audio signal (R), a left channel output audio signal (X1) and a right channel output audio signal (X2) to be transmitted over acoustic propagation paths to a listener, wherein transfer functions of the acoustic propagation paths are defined by an acoustic transfer function matrix. The audio signal processing apparatus comprises a decomposer, a first cross-talk reducer, a second cross-talk reducer, and a combiner. The first cross-talk reducer is configured to reduce a cross-talk within a first predetermined frequency band upon the basis of the acoustic transfer function matrix. The second cross-talk reducer is configured to reduce a cross-talk within a second predetermined frequency band upon the basis of the acoustic transfer function matrix.

Abstract: Noise is suppressed from a microphone array by estimating a noise field isotropy. In some examples audio is received from a plurality of microphones. A power spectral density of a beamformer output is determined and a power spectral density of microphone noise differences is determined. A noise power spectral density is determined using a transfer function and the noise power spectral density is applied to the beamformer output power spectral density to produce a power spectral density output of the received audio with reduced noise.

Abstract: Speech received from a microphone array is enhanced. In one example, a noise filtering system receives audio from the plurality of microphones, determines a beamformer output from the received audio, applies a first auto-regressive moving average smoothing filter to the beamformer output, determines noise estimates from the received audio, applies a second auto-regressive moving average smoothing filter to the noise estimates, and combines the first and second smoothing filter outputs to produce a power spectral density output of the received audio with reduced noise.

Abstract: A computerized method for filtering a digital audio file to generate an output audio file that induces optimal health and cognitive ability in a listener of a playback of the output audio file is described herein. The method includes the steps of identifying a plurality of target frequencies that span within an octave, identifying a plurality of mid-point frequencies that are situated at mid-points between any two adjacent target frequencies, applying a peaking filter to the digital audio file centered around the plurality of mid-point frequencies to produce highest frequency attenuation at the plurality of mid-point frequencies, and generating the output audio file.

Abstract: An interface device is configured to be attached to an audio device and at least one switch within a vehicle. The audio device recognizes a predetermined voltage signal as being a desired audio characteristic and then generates an audio signal having the desired audio characteristic. The interface device includes a central processing unit (CPU) and a wireless receiver. The wireless receiver may receive a wireless data signal from a wireless device corresponding to a desired change to the audio characteristic. The wireless data signal is converted to a first voltage signal. The first voltage signal is transmitted to the CPU. The CPU transforms the first voltage signal to an audio input signal, corresponding to the predetermined voltage signal recognizable by the audio device and corresponding to the desired change to the audio characteristic. The CPU may also receive a second voltage signal, which is converted to the audio input signal.

Abstract: According to an embodiment, a circuit includes a high-? resistor including a plurality of semiconductor junction devices coupled in series and a plurality of additional capacitances formed in parallel with the plurality of semiconductor junction devices. Each semiconductor junction device of the plurality of semiconductor junction devices includes a parasitic doped well capacitance configured to insert a parasitic zero in a noise transfer function of the high-? resistor. Each additional capacitance of the plurality of additional capacitances is configured to adjust a parasitic pole in the noise transfer function of the high-? resistor in order to compensate for the parasitic zero.

Abstract: The present disclosure provides methods, devices and computer program products for encoding and decoding a stereo audio signal based on an input signal. According to the disclosure, a hybrid approach of using both parametric stereo coding and a discrete representation of the stereo audio signal is used which may improve the quality of the encoded and decoded audio for certain bitrates.

Abstract: Acoustic sensing systems having improved vibration cancelation, and methods of achieving improved vibration cancelation. In one example, an acoustic sensing system includes an acoustic sensor configured to produce a sensor output signal representative of a response of the acoustic sensor to acoustic excitation and vibration excitation, at least one accelerometer configured to provide an acceleration signal responsive to the vibration excitation, and a controller, including an adaptive digital filter, coupled to the acoustic sensor and to the at least one accelerometer, and configured to receive the acceleration signal and to adjust coefficients of the adaptive digital filter so as to minimize coherence between a residual signal and the acceleration signal, the residual signal being a difference between the sensor output signal and a filter output signal from the adaptive digital filter.

Abstract: In one aspect, the invention divides an audio signal into auditory events, each of which tends to be perceived as separate and distinct, by calculating the spectral content of successive time blocks of the audio signal, calculating the difference in spectral content between successive time blocks of the audio signal, and identifying an auditory event boundary as the boundary between successive time blocks when the difference in the spectral content between such successive time blocks exceeds a threshold. In another aspect, the invention generates a reduced-information representation of an audio signal by dividing an audio signal into auditory events, each of which tends to be perceived as separate and distinct, and formatting and storing information relating to the auditory events. Optionally, the invention may also assign a characteristic to one or more of the auditory events. Auditory events may be determined according to the first aspect of the invention or by another method.

Abstract: A system for tuning an audio reproduction device is disclosed. The system includes an audio signal generator for generating an audio signal to be played back in an audio reproduction device and sending the audio signal to the audio reproduction device; a microphone signal module for receiving a microphone signal from a microphone, the microphone signal recording a sound wave reproduced by the audio reproduction device when the audio signal is played back in the audio reproduction device; a comparison module for determining whether the microphone signal matches target sound signature data; and a filter module for applying a digital filter to emulate a target sound signature responsive to determining that the microphone signal does not match the target sound signature data.

Abstract: An audio system comprises an audio driver configured to receive a target audio signal and a feedback signal and to generate an adjusted audio signal responsive to the target audio signal and the feedback signal. A loudspeaker is configured to convert the adjusted audio signal into acoustical sound. A test signal generator is configured to generate a test signal having a higher frequency than the target audio signal. The test signal causes a test current to flow through the loudspeaker. A current sensing circuit is configured to measure the test current flowing through the loudspeaker and to generate a current sense signal indicative of the test current. A feedback circuit is configured generates the feedback signal responsive to the current sense signal.

Abstract: A method for characterizing a loudspeaker comprises: filtering an input test signal by applying the inverse of a linear model describing an excursion of the loudspeaker in response to a given input signal, the linear model containing only linear terms; applying the filtered input test signal to the loudspeaker; measuring the excursion of the loudspeaker in response to the filtered input test signal; and, based on the measured excursion, determining one or more non-linear parameters for a non-linear model describing the excursion of the loudspeaker in response to a given input signal.

Abstract: Embodiments of the invention provide methods and apparatus for processing audio input signals, for example, so as to linearize the output of a given loudspeaker. An audio processor is provided, for modifying an audio signal to be provided to a loudspeaker, the audio processor comprising: a first filter stage, for applying to an audio signal a linear model describing an excursion of the loudspeaker in response to a given input signal, the linear model containing only linear terms, and for generating one or more excursion signals; a plurality of second filters for receiving the one or more excursion signals, each of the second filters configured to apply to a respective one of a plurality of frequency bands in the one or more excursion signals the inverse of a model describing an excursion of the loudspeaker in response to a given input signal; and a combiner for combining the outputs of each of the plurality of second filters.

Abstract: An audio driver equipped with a distortion compensation unit corrects for detected distortion and includes a digital to analog converter (DAC), an amplifier, and an output driver that drives a loudspeaker. Between the output driver and the loudspeaker, the audio driver can include a series resistor and a differential amplifier to measure the voltage across the resistor. A distortion detection unit can use the detected voltage to determine whether distortion, such as rub and buzz distortion is present. The distortion detection unit can comprise an analog to digital converter (ADC) to digitize the voltage data, an FFT to transform the voltage data into frequency information, a root-mean-square (RMS) module that measures the energy at each frequency, and an analysis module which looks for the distortion signature in the energy spectrum.

Abstract: Devices and methods for controlling the functionality of a pair of earbuds. The first earbud establishes a connection between the first earbud and an electronic device, searches for the second earbud of the pair of earbuds using Body Coupled Communication, BCC, and sends a signal from the first earbud to the electronic device including information defining whether the first earbud detected the second earbud during the search. The electronic device receives a signal from the at least one of the earbuds, the signal comprising information defining whether the earbud has detected the other earbud of the pair of earbuds using Body Coupled Communication, BCC, and sends a signal to the at least one earbud wherein the signal is controlled based on the received signal and includes information associated with controlling the functionality of the pair of earbuds.

Abstract: In one embodiment a sound generating system comprises: a housing; a speaker located at least partially inside the housing; and an interactive faceplate subassembly comprising: a front surface, wherein a portion of the front surface contains a first plurality of openings forming a speaker grille; a display operable to display through a first portion of the front surface; the display disposed behind the front surface of the interactive faceplate subassembly and coupled to a second surface having a second plurality of openings, and wherein at least one of the openings in the second plurality of openings aligns with one or more of the openings in the first plurality of openings, thereby promoting improved sound transmission from the speaker.

Abstract: An electronic device may include wireless circuitry that is configured to transmit wireless signals during operation. A maximum transmit power level may be established that serves as a cap on how much power is transmitted from the electronic device. Adjustments may be made to the maximum transmit power level in real time based on sensor signals and other information on the operating state of the electronic device. The sensor signals may include motion signals from an accelerometer. The sensor signals may also include ultrasonic sound detected by a microphone. Device orientation data may be used by the device to select whether to measure the ultrasonic sound using a front facing or rear facing microphone. Maximum transmit power level may also be adjusted based on whether or not sound is playing through an ear speaker in the device.