Mega-TTS 2: Zero-Shot Text-to-Speech with Arbitrary Length Speech
  Prompts
Authors: name: Ziyue Jiang, name: Jinglin Liu, name: Yi Ren, name: Jinzheng He, name: Chen Zhang, name: Zhenhui Ye, name: Pengfei Wei, name: Chunfeng Wang, name: Xiang Yin, name: Zejun Ma, name: Zhou Zhao

Zero-shot text-to-speech aims at synthesizing voices with unseen speech
prompts. Previous large-scale multispeaker TTS models have successfully
achieved this goal with an enrolled recording within 10 seconds. However, most
of them are designed to utilize only short speech prompts. The limited
information in short speech prompts significantly hinders the performance of
fine-grained identity imitation. In this paper, we introduce Mega-TTS 2, a
generic zero-shot multispeaker TTS model that is capable of synthesizing speech
for unseen speakers with arbitrary-length prompts. Specifically, we 1) design a
multi-reference timbre encoder to extract timbre information from multiple
reference speeches; 2) and train a prosody language model with arbitrary-length
speech prompts; With these designs, our model is suitable for prompts of
different lengths, which extends the upper bound of speech quality for
zero-shot text-to-speech. Besides arbitrary-length prompts, we introduce
arbitrary-source prompts, which leverages the probabilities derived from
multiple P-LLM outputs to produce expressive and controlled prosody.
Furthermore, we propose a phoneme-level auto-regressive duration model to
introduce in-context learning capabilities to duration modeling. Experiments
demonstrate that our method could not only synthesize identity-preserving
speech with a short prompt of an unseen speaker but also achieve improved
performance with longer speech prompts. Audio samples can be found in
https://mega-tts.github.io/mega2_demo/.