US Patent 11551700 Systems and methods for power-efficient keyword detection

Systems and methods for audio processing include capturing sound data via at least one microphone of a network microphone device (NMD) and determining whether the captured sound includes voice activity. While in a first stage, the NMD forgoes spatial processing of the captured sound data. If the NMD determines that the detected sound includes voice activity, the NMD transitions to a second stage. In this second stage, the NMD spatially processes the detected sound to produce filtered sound data and detects a wake word. After detecting the wake word, the NMD may determine an action to be performed based on the captured sound data.