MELD: Mel-Spectrogram-Based Speech Language Modeling with Discrete Latent Variables

Sung-Lin Yeh, Wei Zhou, Gil Keren, Duc Le, Zhong Meng, Hao Tang, Jay Mahadeokar, Ozlem Kalinli, Alexandre Mourachko


Abstract
Recent speech language models rely on encoders that are optimized separately from autoregressive models. Since these encoders are unaware of the downstream objectives, the extracted representations may not be optimal for downstream tasks. To address this limitation, we introduce a discrete latent variable model on mel spectrograms that jointly optimizes the encoder and the speech language model. Joint optimization not only brings improvements over codec-based and other mel-spectrogram-based baselines on zero-shot Text-to-Speech (TTS) and Speech-to-Text (STT) tasks, but also effectively alleviates common issues in autoregressive mel spectrogram modeling, such as prolonged silence generation and word omissions. Samples are available at the [demo page](https://anonymous29300909.github.io/anonymous2930-demo/).
Anthology ID:
2026.emnlp-main.1584
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
36038–36050
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1584/
DOI:
Bibkey:
Cite (ACL):
Sung-Lin Yeh, Wei Zhou, Gil Keren, Duc Le, Zhong Meng, Hao Tang, Jay Mahadeokar, Ozlem Kalinli, and Alexandre Mourachko. 2026. MELD: Mel-Spectrogram-Based Speech Language Modeling with Discrete Latent Variables. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 36038–36050, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
MELD: Mel-Spectrogram-Based Speech Language Modeling with Discrete Latent Variables (Yeh et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1584.pdf