Abstract: A wireless audio device includes one or more electroacoustic transducers and a first wireless transceiver. The device also includes a processor configured to (a) process audio signals received by the transceiver in a first received signal and communicate the processed audio signals to the transducer(s) to cause the transducer(s) to output sound pressure waves, (b) determine that a characteristic of a second received signal independent of the first received signal surpassed at least one threshold, and (c) change a state of the audio device based on the determining.

Abstract: A wireless audio device includes one or more electroacoustic transducers and a first wireless transceiver. The device also includes a processor configured to (a) process audio signals received by the transceiver in a first received signal and communicate the processed audio signals to the transducer(s) to cause the transducer(s) to output sound pressure waves, (b) determine that a characteristic of a second received signal independent of the first received signal surpassed at least one threshold, and (c) change a state of the audio device based on the determining.

Abstract: An active noise reducing headphone has an active noise-cancelling mode and an active hear-through mode, and changes between the noise-cancelling mode and the hear-through mode based on detection of a user touching a housing of the headphone or based on a command signal received from an external device. In another aspect, a signal processor in the headphone is configured to change between the active noise-cancelling and active hear-through modes based on a comparison of signals from a feed-forward microphone and a feedback microphone. During the hear-through mode, the signal processor detects high-frequency signals in the feed-forward path exceeding a threshold level indicative of abnormally high acoustic coupling of the output transducer to the feed-forward microphone, and applies a compressing limiter to the feed-forward path until the high-frequency signals are no longer detected at levels above the threshold.