Abstract: Embodiments of the invention determine a speech estimate using a bone conduction sensor or accelerometer, without employing voice activity detection gating of speech estimation. Speech estimation is based either exclusively on the bone conduction signal, or is performed in combination with a microphone signal. The speech estimate is then used to condition an output signal of the microphone. There are multiple use cases for speech processing in audio devices.

Abstract: A crosstalk canceller for reducing acoustic crosstalk at a time of audio playback is derived by forming a channel frequency response for a nominated playback geometry, and decomposing the channel frequency response to derive a decomposition element such as a singular value decomposition matrix. A value of the decomposition element, such as the smallest singular value, is then adjusted to reduce spectral coloration, and filter coefficients of a crosstalk cancellation filter are derived from the adjusted decomposition element.

Abstract: Processing digitized microphone signal data in order to detect wind noise. A first signal and a second signal are obtained from at least one microphone. The first and second signals reflect a common acoustic input, and are either temporally distinct or spatially distinct, or both. The first signal is processed to determine a first distribution of the samples of the first signal. The second signal is processed to determine a second distribution of the samples of the second signal. A difference between the first distribution and the second distribution is calculated. If the difference exceeds a detection threshold, an indication is output that wind noise is present.

Abstract: A crosstalk canceller for reducing acoustic crosstalk at a time of audio playback is derived by forming a channel frequency response for a nominated playback geometry, and decomposing the channel frequency response to derive a decomposition element such as a singular value decomposition matrix. A value of the decomposition element, such as the smallest singular value, is then adjusted to reduce spectral coloration, and filter coefficients of a crosstalk cancellation filter are derived from the adjusted decomposition element.

Abstract: Processing digitized microphone signal data in order to detect wind noise. A first signal and a second signal are obtained from at least one microphone. The first and second signals reflect a common acoustic input, and are either temporally distinct or spatially distinct, or both. The first signal is processed to determine a first distribution of the samples of the first signal. The second signal is processed to determine a second distribution of the samples of the second signal. A difference between the first distribution and the second distribution is calculated. If the difference exceeds a detection threshold, an indication is output that wind noise is present.

Abstract: An acoustic crosstalk canceller is determined for an asymmetric audio playback device, by determining a transfer function of an acoustic stereo playback path having asymmetries defined by speakers of the playback device. The transfer function is inverted to determine an inverse transfer function. The inverse transfer function is regularised by applying frequency dependent regularisation parameters to obtain an acoustic crosstalk canceller. Also, the inverse transfer function could be regularised for symmetric playback paths by applying aggregated frequency dependent regularisation parameters to obtain an acoustic crosstalk canceller without band branching.

Abstract: Processing digitized microphone signal data in order to detect wind noise. A first signal and a second signal are obtained from at least one microphone. The first and second signals reflect a common acoustic input, and are either temporally distinct or spatially distinct, or both. The first signal is processed to determine a first distribution of the samples of the first signal. The second signal is processed to determine a second distribution of the samples of the second signal. A difference between the first distribution and the second distribution is calculated. If the difference exceeds a detection threshold, an indication is output that wind noise is present.

Abstract: A method of wind noise reduction. Left side and right side microphone signals are obtained. In a first stage wind noise reduction is applied to a first sub-band of one of the signals, below a spectral threshold NA. In a second stage the wind noise reduced first side signal, and the second side signal, are both split into a sub-band below a threshold NB less than NA. The sub-band of the first side signal is mixed with the sub-band of the second side signal to produce an aggregate third sub-band signal having reduced wind noise, which is recombined with the respective sub-bands above the threshold NB to produce output first and second side signals.

Abstract: A method of adaptively mapping a plurality of microphone signals to a multi-channel audio signal, for example to capture stereo audio from a device held in variable orientations. At least first and second microphone signals, from respective first and second spaced apart microphones, are obtained. A device orientation signal is also obtained from a device orientation sensor. The microphone signals are adaptively mapped, based on the device orientation signal, to produce a first audio signal channel of a multi-channel audio signal. The first and second microphone signals are also adaptively mapped, based on the device orientation signal, to produce a second audio signal channel of a multi-channel audio signal.

Abstract: A method of wind noise reduction. Left side and right side microphone signals are obtained. In a first stage wind noise reduction is applied to a first sub-band of one of the signals, below a spectral threshold NA. In a second stage the wind noise reduced first side signal, and the second side signal, are both split into a sub-band below a threshold NB less than NA. The sub-band of the first side signal is mixed with the sub-band of the second side signal to produce an aggregate third sub-band signal having reduced wind noise, which is recombined with the respective sub-bands above the threshold NB to produce output first and second side signals.

Abstract: The present application relates to a method and an apparatus for synchronizing a receiver timing to a transmitter timing using a known preamble of a signal. In at least one embodiment of the method and/or the apparatus of the present application, a power normalized cross-correlation metric (PNCC metric) is estimated based on a signal power and a noise floor power. According to a first embodiment, two cross-correlation functions, one based on the PNCC metric and the other based on a cross-correlation metric, are used to decide if synchronization events occur and based on the analysis of time indexes and PNCC magnitude values, a timing synchronization index used to synchronize receiver timing to transmitter timing is determined. According to a second embodiment, the cross-correlation function based on the PNCC metric is used to decide if synchronization events occur and based on an analysis of time indexes and PNCC magnitude values using a clustering approach, a timing synchronization index is determined.

Abstract: The present application relates to a method and an apparatus for synchronising a receiver timing to a transmitter timing using a known preamble of a signal. In at least one embodiment of the method and/or the apparatus of the present application, a power normalised cross-correlation metric (PNCC metric) is estimated based on a signal power and a noise floor power. According to a first embodiment, two cross-correlation functions, one based on the PNCC metric and the other based on a cross-correlation metric, are used to decide if synchronisation events occur and based on the analysis of time indexes and PNCC magnitude values, a timing synchronisation index used to synchronise receiver timing to transmitter timing is determined. According to a second embodiment, the cross-correlation function based on the PNCC metric is used to decide if synchronisation events occur and based on an analysis of time indexes and PNCC magnitude values using a clustering approach, a timing synchronisation index is determined.

Abstract: A novel approach for determining signal to noise ratios based on equalizer outputs and managing power for a plurality of communications channels based on communications channel performance is disclosed. According to one aspect of the invention, a noise power is generated based on an error output of an equalizer that receives input from a communications channel, and a signal power is generated based on a signal output of the equalizer. A signal to noise ratio is determined based on the noise power and the signal power. According to another aspect of the invention, a first power and a second power that is different than the first power are determined based on performance data for the plurality of communications channels. The first power is used for communications that use a first communications channel, and the second power is used for communications that use a second communications channel.

Abstract: A novel approach for managing power for a plurality of communications channels based on communications channel performance is disclosed. According to one aspect of the invention, a first power and a second power that is different than the first power are determined based on performance data for the plurality of communications channels. The first power is used for communications that use a first communications channel, and the second power is used for communications that use a second communications channel. According to another aspect of the invention, a noise power is generated based on an error output of an equalizer that receives input from a communications channel, and a signal power is generated based on a signal output of the equalizer. A signal to noise ratio is determined based on the noise power and the signal power.