Speaker-dependent multipitch tracking using deep neural networks.

Multipitch tracking is important for speech and signal processing. However, it is challenging to design an algorithm that achieves accurate pitch estimation and correct speaker assignment at the same time. In this paper, deep neural networks (DNNs) are used to model the probabilistic pitch states of two simultaneous speakers. To capture speaker-dependent information, two types of DNN with different training strategies are proposed. The first is trained for each speaker enrolled in the system (speaker-dependent DNN), and the second is trained for each speaker pair (speaker-pair-dependent DNN). Several extensions, including gender-pair-dependent DNNs, speaker adaptation of gender-pair-dependent DNNs and training with multiple energy ratios, are introduced later to relax constraints. A factorial hidden Markov model (FHMM) then integrates pitch probabilities and generates the most likely pitch tracks with a junction tree algorithm. Experiments show that the proposed methods substantially outperform other speaker-independent and speaker-dependent multipitch trackers on two-speaker mixtures. With multi-ratio training, the proposed methods achieve consistent performance at various energies ratios of the two speakers in a mixture.