titleTacit-TTS: From Autoregressive Decoding to Masked Prediction for Efficient Transcript-Free Voice Cloning
authorsJian Chen, You Zhang, Mark Vinton
date2026-09-29
venuearXiv (preprint, not peer reviewed)
idarXiv:2609.38658
upvotes13 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractTTS systems with autoregressive semantic modeling have demonstrated strong zero-shot voice cloning performance and rich expressive variation, but their sequential decoding incurs substantial latency. Non-autoregressive alternatives offer much faster generation, yet often rely on more restrictive reference conditioning, such as requiring transcripts of the reference speech during inference. We present Tacit-TTS, an efficient transcript-free zero-shot voice cloning system distilled from IndexTTS2. Our model replaces autoregressive text-to-semantic decoding with masked non-autoregressive generation, introduces training-free acoustic length estimation, and accelerates the flow-matching renderer through ReFlow distillation. Across two English and two Mandarin datasets, Tacit-TTS achieves competitive zero-shot quality while generating speech over 10x faster than IndexTTS2 for utterances longer than 5 seconds. Its transcript-free conditioning further supports cross-lingual and non-lexical references. We validate this capability using references from eight other languages, infant babble, and synthetic gibberish, where transcript-dependent systems often degrade or fail due to unreliable ASR transcripts.

cite

@misc{chen2026tacit,
  title={Tacit-TTS: From Autoregressive Decoding to Masked Prediction for Efficient Transcript-Free Voice Cloning},
  author={Jian Chen and You Zhang and Mark Vinton},
  year={2026},
  eprint={2609.38658},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2609.38658}
}