Frame-level multi-channel speaker verification with large-scale ad-hoc microphone arrays

Ad-hoc microphone arrays has recieved attention, in which the number and arrangement of microphones are unknown. Traditional multi-channel processing methods can not be directly used in ad-hoc. Recently, to solve this problem, an utterance-level ASV with ad-hoc microphone arrays has been proposed, which first extracts utterance-level speaker embeddings from each channel of an ad-hoc microphone array, and then fuses the embeddings for the final verification. However, this method cannot make full use of the cross-channel information. In this paper, we present a novel multi-channel ASV model at the frame-level. Specifically, we add spatio-temporal processing blocks (STB) before the pooling layer, which models the contextual relationship within and between channels and across time, respectively. The channel-attended outputs from STB are sent to the pooling layer to obtain an utterance-level speaker representation. Experimental results demonstrate the effectiveness of the proposed method.