Low power detection of an activation phrase

摘要

A microphone system 102 comprises dedicated hardware logic 112 for detecting a pre-defined activation phrase in an audio stream received via a microphone 110. If the pre-defined activation phrase is detected, the hardware logic 112 sends a trigger signal to activate a module 104 which is external to the microphone system 102 and which may be in a low power standby state. The pre-defined phrase may comprise one or more spoken words or may be a sample of a contextual sound. The phrase may be an activation phrase for a voice controlled computing device 100. The external module 104 may be a main speech detection module implemented by a processor in the voice controlled computing device. Using hardware logic in the microphone system allows the processor within the computing device to be switched off or placed into a low power state. Consequently, the battery life of the voice controlled device can be extended.