Multi-Microphone Adaptive Noise Cancellation for Robust Hotword Detection

Recently we proposed a dual-microphone adaptive noise cancellation (ANC) algorithm with deferred filter coefficients for robust hotword detection in [1]. It exploits two unique hotword-related features: hotwords are the leading phrase of valid voice queries and they are short. These features allow us not to compute a speech-noise mask that is a common prerequisite for many multichannel speech enhancement approaches. This novel idea was found effective against strong and ambiguous speech-like TV noise. In this paper, we show that it can be generalized to support more than two microphones. The development is validated using re-recorded data with background TV noise from a 3-mic array. By adding one more microphone, the false reject (FR) rate can be further reduced relatively by 33.5%.