Wearable audio accessories for computing devices are described. In one embodiment the wearable audio accessory provides a speech based interface between the user and a nearby computing device for the performance of user-initiated or computing device initiated microtasks. Information is provided to the user via a loudspeaker and the user can provide input via a microphone. An audio sensing channel within the accessory continuously monitors the audio signal as detected by the microphone and in various embodiments will trigger more complex audio processing based on this monitoring. A wireless communication link is provided between the accessory and the nearby computing device. To mitigate any delay caused by the switching between audio processing techniques, the audio accessory may include a rolling buffer which continuously stores the audio signal and outputs a delayed audio signal to the audio processing engines.