Deep Speaker Embedding for Speaker-Targeted Automatic Speech Recognition

In this work, we investigate three types of deep speaker embedding as text-independent features for speaker-targeted speech recognition in cocktail party environments. The text-independent speaker embedding is extracted from the target speaker's existing speech segment (i-vector and x-vector) or face image (f-vector), which is concatenated with acoustic features of any new speech utterances as input features. Since the proposed model extracts the speaker embedding of the target speaker once and for all, it is computationally more efficient than many prior approaches which estimate the target speaker's characteristics on the fly. Empirical evaluation shows that using speaker embedding along with acoustic features improves Word Error Rate over the audio-only model, from 65.7% to 29.5%. Among the three types of speaker embedding, x-vector and f-vector show robustness against environment variations while i-vector tends to overfit to the specific speaker and environment condition.