An internal microphone signal of a headphone is filtered by i) a first filter G that, as part of an acoustic noise cancellation, ANC, subsystem, produces an anti-noise audio signal, and ii) a second filter C to produce a feedback audio signal. An estimate of a transfer function of a path S is determined, wherein the path S is from i) an input of a speaker of the headphone to ii) the internal microphone signal. The second filter C is adapted based on the estimate of the transfer function of the path S drives an input of a speaker of the headphone. Other embodiments are also described.

A noise reduction device includes a processor that converts a noise signal collected by a microphone disposed in a control space into a noise signal in a frequency domain, a storage that stores the converted noise signal in the frequency domain as a reference signal, and a signal generator that generates a noise reduction signal for reducing the noise signal collected by the microphone at a control position of the control space. The processor determines whether or not the noise signal is non-stationary noise based on a frequency characteristic of the converted noise signal in the frequency domain and a frequency characteristic of the reference signal. When it is determined that the noise signal is the non-stationary noise, the processor controls the signal generator so as to cancel generation of the noise reduction signal.

An audio system for an ear mountable playback device comprises a speaker, an error microphone predominantly sensing sound being output from the speaker and a feed-forward microphone predominantly sensing ambient sound. The audio system further comprises a voice activity detector which is configured to record a feed-forward signal from the feed-forward microphone. Furthermore, an error signal is recorded from the error microphone. A detection parameter is determined as a function of the feed-forward signal and the error signal. The detection parameter is monitored and a voice activity state is set depending on the detection parameter.

Embodiments of systems and methods for adaptive sound equalization in personal hearing devices are disclosed. In some embodiments a microphone in a personal hearing device receives sound from the listener's environment. The sound then is analyzed to determine one or more desired targets, for instance loudness level or spectral balance. The determined targets then are used to control adaptive processing of the sound received by the microphone to generate a perceptually improved sound to render to the listener.

An adaptive noise cancelling system utilizing a plurality of multi-axis accelerometers and a plurality of microphones, wherein the plurality of multi-axis accelerometers and the plurality microphones may be used in combination to pick up vibrations on a chassis of a vehicle. The accelerometers may be positioned at point near the suspension knuckles or joints of the vehicle, and the microphones may be positioned near the headrest and sun visor of the vehicle. The adaptive noise cancelling system may use an adaptive algorithm to derive one or more filter weights that model a transfer function between the vibrations on the chassis of the vehicle to an acoustic pressure at the plurality of microphones location.

Provided is a technology for generating an elimination filter coefficient for suppressing degradation of noise elimination performance. An elimination filter coefficient generation method for inputting a reference signal output from a reference microphone for collecting noise and an error signal output from an error microphone for collecting sound at a position that needs to be silent, and generating an elimination filter coefficient used for filtering for generating an elimination signal for eliminating noise at the position that needs to be silent from the reference signal includes: a route filtering step for generating a filtered reference signal from the reference signal by filtering using a route filter coefficient indicating acoustic characteristics of a route from a speaker for emitting sound based on the elimination signal to the error microphone; a first noise signal generation step for generating a predetermined signal as a first noise signal; a noise signal addition step for generating an added reference signal from the filtered reference signal and the first noise signal; and an elimination filter coefficient generation step for generating the elimination filter coefficient from the error signal and the added reference signal.

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.

There is provided a mechanism that enables cooperation of a plurality of audio processing devices. An earphone device includes a sensor unit that detects an overlapping state of the earphone device and a headphone device and a wireless communication unit that wirelessly communicates with the headphone device which is worn to overlap an outer side of the earphone device worn by a user.

An audio system for an ear mountable playback device comprises a speaker, an error microphone configured to predominantly sense sound being output from the speaker and a further microphone configured to predominantly sense ambient sound. The system further comprises a first noise filter coupling the further microphone to the speaker, a second noise filter coupling the error microphone to the speaker and an adaptation engine. The adaptation engine is configured to adapt a response of the first noise filter depending on error signals from at least the error microphone, estimate a leakage condition from the response of the first noise filter, and adapt a response of the second noise filter depending on the estimated leakage condition.

An ear cup housing has several reference microphones, an error microphone and a speaker. A processor drives the speaker for acoustic noise cancellation and transparency, by processing the microphone signals, and performs an oversight process by adjusting the reference microphone signals in response to detecting wind noise events and scratch events. In another aspect, the ear cup housing has an outside face that is joined to an inside face by a perimeter and the reference microphones are on the perimeter. Other aspects are also described and claimed.