Domain Adaptation for Speaker Verification Using Optimal Transport with Pseudo Label

Domain gap often degrades the performance of speaker verification (SV) systems when the statistical distributions of training data and real-world test speech are mismatched. Channel variation is a primary factor causing this gap, including bandwidth changes, background noise and encoding, etc. Although various domain adaptation algorithms could be applied to handle this domain gap problem, most algorithms could not take the complex distribution structure in domain alignment with discriminative learning. In this paper, we propose a novel unsupervised domain adaptation method for speaker verification, i.e., Joint Partial Optimal Transport with Pseudo Label (JPOT-PL), to alleviate the domain mismatch problem. Leveraging the geometric-aware distance metric of optimal transport in distribution alignment and speaker consistency in speech distribution, we further design a pseudo label-based discriminative learning where the pseudo label can be regarded as a new type of speaker label derived from the optimal coupling. With the JPOT-PL, we carry out experiments on the SV channel and lingual domain adaptation with VoxCeleb, LibriSpeech, CNCeleb, and AISHELL-2. Experiments show our method reduces EER by up to 30% compared with several state-of-the-art domain adaptation algorithms.