In this paper, we present the voice conversion (VC) systems developed at Nagoya University (NU) for the Voice Conversion Challenge 2020 (VCC2020). We aim to determine the effectiveness of two recent significant technologies in VC: sequence-to-sequence (seq2seq) models and autoregressive (AR) neural vocoders. Two respective systems were developed for the two tasks in the challenge: for task 1, we adopted the Voice Transformer Network, a Transformer-based seq2seq VC model, and extended it with synthetic parallel data to tackle nonparallel data; for task 2, we used the frame-based cyclic variational autoencoder (CycleVAE) to model the spectral features of a speech waveform and the ARWaveNet vocoder with additional fine-tuning. By comparing with the baseline systems, we confirmed that the seq2seq modeling can improve the conversion similarity and that the use of AR vocoders can improve the naturalness of the converted speech.
Cite as: Huang, W.-C., Tobing, P.L., Wu, Y.-C., Kobayashi, K., Toda, T. (2020) The NU Voice Conversion System for the Voice Conversion Challenge 2020: On the Effectiveness of Sequence-to-sequence Models and Autoregressive Neural Vocoders. Proc. Joint Workshop for the Blizzard Challenge and Voice Conversion Challenge 2020, 165-169, doi: 10.21437/VCCBC.2020-25
@inproceedings{huang20b_vccbc,
author={Wen-Chin Huang and Patrick Lumban Tobing and Yi-Chiao Wu and Kazuhiro Kobayashi and Tomoki Toda},
title={{The NU Voice Conversion System for the Voice Conversion Challenge 2020: On the Effectiveness of Sequence-to-sequence Models and Autoregressive Neural Vocoders}},
year=2020,
booktitle={Proc. Joint Workshop for the Blizzard Challenge and Voice Conversion Challenge 2020},
pages={165--169},
doi={10.21437/VCCBC.2020-25}
}