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Koel-TTS: Enhancing LLM based Speech Generation with Preference Alignment and Classifier Free Guidance

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arxiv 2502.05236 v2 pith:VVZEAHQU submitted 2025-02-07 cs.SD cs.AIcs.LGeess.AS

Koel-TTS: Enhancing LLM based Speech Generation with Preference Alignment and Classifier Free Guidance

classification cs.SD cs.AIcs.LGeess.AS
keywords speechmodelsaudiokoel-ttsspeakeralignmentgenerationguidance
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
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While autoregressive speech token generation models produce speech with remarkable variety and naturalness, their inherent lack of controllability often results in issues such as hallucinations and undesired vocalizations that do not conform to conditioning inputs. We introduce Koel-TTS, a suite of enhanced encoder-decoder Transformer TTS models that address these challenges by incorporating preference alignment techniques guided by automatic speech recognition and speaker verification models. Additionally, we incorporate classifier-free guidance to further improve synthesis adherence to the transcript and reference speaker audio. Our experiments demonstrate that these optimizations significantly enhance target speaker similarity, intelligibility, and naturalness of synthesized speech. Notably, Koel-TTS directly maps text and context audio to acoustic tokens, and on the aforementioned metrics, outperforms state-of-the-art TTS models, despite being trained on a significantly smaller dataset. Audio samples and demos are available on our website.

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Forward citations

Cited by 7 Pith papers

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  4. Unified Audio Intelligence Without Regressing on Text Intelligence

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  5. Cross-modal Consistency Guidance for Robust Emotion Control in Auto-Regressive TTS Models

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    cs.CL 2025-10 reject novelty 5.0

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