Abstract: A headphone device includes a speaker housing, a first feedforward microphone, and a second feedforward microphone. The first feedforward microphone is coupled to the speaker housing at a first location, and the second feedforward microphone is coupled to the speaker housing at a second location. The headphone device also includes an active noise cancelling (ANC) circuit configured to generate an anti-noise signal based on at least one of a first signal from the first feedforward microphone and a second signal from the second feedforward microphone. The headphone device also includes a speaker configured to generate an audio output at least partially based on the anti-noise signal.

Abstract: A headphone device includes a speaker housing, a first feedforward microphone, and a second feedforward microphone. The first feedforward microphone is coupled to the speaker housing at a first location, and the second feedforward microphone is coupled to the speaker housing at a second location. The headphone device also includes an active noise cancelling (ANC) circuit configured to generate an anti-noise signal based on at least one of a first signal from the first feedforward microphone and a second signal from the second feedforward microphone. The headphone device also includes a speaker configured to generate an audio output at least partially based on the anti-noise signal.

Abstract: Techniques are described for assisting near distance communications. A first device comprising a receiver, a sensor and a processor may be configured to perform the assisted near distance communication techniques. The receiver may receive, from a second device located within a conversational distance to the first device, monophonic audio data representative of the near distance communication. The sensor may generate a sensor signal representative of spatial information of the near distance communication. The processor may render, based on the spatial information and the monophonic audio data, multi-dimensional audio data in which the near distance communication originates in a soundfield from a location of the second device relative to the first device. The processor may next output the multi-dimensional audio data to a transducer so as to reproduce the near distance communication in multiple dimensions.

Abstract: A method for feedback detection by an electronic device is described. The method includes receiving a first microphone signal by a first microphone. A feedback loop includes the first microphone and a speaker. The method also includes receiving a second microphone signal by a second microphone that is outside of the feedback loop. A first signal based on the first microphone signal and a second signal based on the second microphone signal exhibit a higher correlation in presence of feedback and exhibit a lower correlation in absence of feedback. The method further includes determining a correlation based on the first microphone signal and the second microphone signal. The method additionally includes determining whether feedback is occurring based on the correlation.

Abstract: A method of audio signal processing includes determining a difference between a first set of filter parameters of a first input frame of an active noise cancellation (ANC) filter and a second set of filter parameters of a second input frame of the ANC filter. The method further includes selectively modifying a duty cycle of adaptive ANC processing associated with the ANC filter based on the difference between the first set of filter parameters and the second set of filter parameters.

Abstract: In general, techniques are described for limiting active noise cancellation output. As one example, an apparatus comprising one or more processors may perform the techniques. The one or more processors may be configured to, when an estimated noise level increases, dynamically lowering application of active noise cancellation to at least a portion of an audio signal to obtain at least a portion of an active noise cancelled version of the audio signal.

Abstract: A method of audio signal processing includes determining a difference between a first set of filter parameters of a first input frame of an active noise cancellation (ANC) filter and a second set of filter parameters of a second input frame of the ANC filter. The method further includes selectively modifying a duty cycle of adaptive ANC processing associated with the ANC filter based on the difference between the first set of filter parameters and the second set of filter parameters.

Abstract: A method includes receiving, at a processor, a first data frame at a first time from a first microphone. The method also includes receiving a second data frame at the first time from a second microphone. The method further includes calculating a power ratio of the first microphone and the second microphone based on the first data frame and the second data frame in response to determining that the first data frame and the second data frame are noise data frames.

Abstract: A method for feedback detection by an electronic device is described. The method includes receiving a first microphone signal by a first microphone. A feedback loop includes the first microphone and a speaker. The method also includes receiving a second microphone signal by a second microphone that is outside of the feedback loop. A first signal based on the first microphone signal and a second signal based on the second microphone signal exhibit a higher correlation in presence of feedback and exhibit a lower correlation in absence of feedback. The method further includes determining a correlation based on the first microphone signal and the second microphone signal. The method additionally includes determining whether feedback is occurring based on the correlation.

Abstract: In general, techniques are described for limiting active noise cancellation output. As one example, an apparatus comprising one or more processors may perform the techniques. The one or more processors may be configured to, when an estimated noise level increases, dynamically lowering application of active noise cancellation to at least a portion of an audio signal to obtain at least a portion of an active noise cancelled version of the audio signal.

Abstract: A method includes receiving, at a processor, a first data frame at a first time from a first microphone. The method also includes receiving a second data frame at the first time from a second microphone. The method further includes calculating a power ratio of the first microphone and the second microphone based on the first data frame and the second data frame in response to determining that the first data frame and the second data frame are noise data frames.

Abstract: An echo canceller for improved recognition and removal of an echo from a communication device. The echo canceller can dynamically reduce echo using an improved energy estimator and an improved adaptive filter. The improved energy estimator can determine if conversation is in a single talk period or a double talk period based on the combined energy of both the near end background noise and speech. The improved adaptive filter can reduce echo by dynamically changing adaptation speed or step size. In double talk, the adaptive filter(s) can dynamically slow-down or stop adaptation. In single talk, the filter can dynamically increase the speed of adaptation to improve accuracy, or decrease adaptation speed for stability.