Disclosed herein are methods for operating an apparatus for generating acoustic compensation signals used to compensate acoustic signals from operation of a motor-vehicle engine, comprising the steps: providing an EOC device, which is designed to generate acoustic compensation signals used to compensate acoustic signals that result from the operation of the engine; providing a device configured using the EOC device as a model; determining at least one audio signal to be output into a passenger compartment of a motor vehicle by means of an audio output device, before said audio signal is captured by an audio capturing element associated with the EOC device; applying an evaluation specification to evaluate the at least one audio signal with respect to at least one evaluation criterion; generating evaluation information with respect to the at least one evaluation criterion; controlling the operation of the EOC device on the basis of the evaluation Information.

Headphones includes a pair of cups, each housing a speaker to be positioned over an ear of a user, a microphone, a processor, an actuator to move a member of at least one of the cups to uncover at least a portion of the ear of the user to expose the user to ambient sound, a user control to active a training mode of the headphones in which the processor operates the microphone to record relevant sounds occurring when the training mode is activated, the processor to subsequently analyze ambient sounds external to the headphones that are received by the microphone and compare those ambient sounds to the recorded relevant sounds and the processor to selectively activate the actuator to uncover at least a portion of the ear of the user to expose the user to ambient sound in response to determining that the ambient sounds match the relevant sounds.

Embodiments of active noise control (ANC) headphones and operating methods thereof are disclosed herein. In one example, a headphone for ANC includes a speaker, an internal microphone, a processor, and a filter function module. The speaker is configured to play an audio based on a first audio source signal. The internal microphone is configured to obtain a mixed audio signal comprising a noise signal and a second audio source signal based on the audio of interest played by the speaker. The processor is configured to determine a current system parameter of the ANC headphone based on the mixed audio signal at a first time point and determine a current parameter of a filter function module based on the current system parameter of the ANC headphone and pre-tested data. The filter function module is to perform ANC based on the determined current parameter of the filter function module.

Embodiments of active noise control (ANC) headphones and operating methods thereof are disclosed herein. In one example, a headphone includes a speaker, an internal microphone, and a processor. The speaker is configured to play an audio of interest based on an audio source signal. The internal microphone is configured to obtain a mixed audio signal including a noise signal and the audio of interest played by the speaker. The processor is configured to determine a first current system parameter of the headphone based on the mixed audio signal at a first time point, and determine if the first current system parameter of the headphone is higher than a predetermined threshold to determine if the headphone is worn by a user.

Adaptive noise cancellation systems and methods comprise a reference sensor operable to sense environmental noise and generate a corresponding reference signal, an error sensor operable to sense noise in a noise cancellation zone and generate a corresponding error signal, a noise cancellation filter operable to receive the reference signal and generate an anti-noise signal to cancel the environmental noise in the cancellation zone, an adaptation module operable to receive the reference signal and the error signal and adaptively adjust the anti-noise signal, and a transient activity detection module operable to receive the reference signal, detect a transient noise event and selectively disable the adaptation module during the detected transient noise event.

A networked speaker system includes plural speaker assemblies around the perimeter of a space with sound axes oriented up and inward into the space. Each speaker assembly includes an audio transducer to output demanded sound and a noise cancelation transducer which is driven to cancel sound from other speaker assemblies in the space based on signals from a microphone on the speaker assembly and location and device information from the other speaker assemblies.

An apparatus receives a background audio signal from an earpiece microphone. The earpiece microphone is configured to convert sound from a surrounding environment into the background audio signal. The apparatus outputs, to at least one speaker, a primary audio signal with an altered version of the background audio signal. The altered version is selectable, responsive to control by a user of a user interface, between an amount of active noise cancelation of the sound and an amount of reproduction of the sound. One example embodiment is a headset with microphones and speakers for the respective inputs and outputs.

The technology described in this document can be embodied in a method that includes receiving a plurality of representations of the signal corresponding to samples of the signal within a frame of predetermined time duration, and estimating a power spectral density (PSD) for each of a plurality of frequency bins. The PSD for a particular frequency bin is estimated based on a smoothing parameter calculated from a noise estimate for the particular frequency bin as obtained from samples corresponding to a preceding frame. The method also includes generating, based on the PSD for each of the plurality of frequency bins, an estimate of the steady-state noise floor, and computing a measure of spectral flatness associated with the samples within the frame. The method also includes determining that the measure of spectral flatness satisfies a threshold condition, and in response, computing an updated estimate of the steady-state noise floor.

An audio processing system can include an Analog to Digital Converter structured to receive an analog input signal and convert the analog input signal to a digital input signal, a first processor coupled with the Analog to Digital Converter, the first processor including at least one programmable bi-quadratic filter chain structured to receive the digital input signal from the Analog to Digital Converter and perform audio processing on the received digital input signal at a first clock rate, and a second processor coupled with the first processor and the Analog to Digital Converter and structured to receive the digital input signal from the Analog to Digital Converter and perform audio processing on the received digital input signal at a second clock rate that is different from the first clock rate.

Disclosed is a signal processor for headphone off-ear detection. The signal processor includes an audio output to transmit an audio signal toward a headphone speaker in a headphone cup. The signal processor also includes a feedback (FB) microphone input to receive a FB signal from a FB microphone in the headphone cup. The signal processor also includes an off-ear detection (OED) signal processor to determine an audio frequency response of the FB signal over an OED frame as a received frequency response. The OED processor also determines an audio frequency response of the audio signal times an off-ear transfer function between the headphone speaker and the FB microphone as an ideal off-ear response. A difference metric si generated comparing the received frequency response to the ideal off-ear frequency response. The difference metric is employed to detect when the headphone cup is disengaged from an ear.