RLAIF-SPA: Structured AI Feedback for Semantic-Prosodic Alignment in Speech Synthesis
On the map: LLM alignment / RLHF / preference optimisation → Preference alignment for recommenders and RAG
Abstract (arXiv)
Recent advances in Text-To-Speech (TTS) synthesis have achieved near-human speech quality in neutral speaking styles. However, most existing approaches either depend on costly emotion annotations or optimize surrogate objectives that fail to adequately capture perceptual emotional quality. As a result, the generated speech, while semantically accurate, often lacks expressive and emotionally rich characteristics. To address these limitations, we propose RLAIF-SPA, a novel framework that integrates Reinforcement Learning from AI Feedback (RLAIF) to directly optimize both emotional expressiveness and intelligibility without human supervision. Specifically, RLAIF-SPA incorporates Automatic Speech Recognition (ASR) to provide semantic accuracy feedback, while leveraging structured reward modeling to evaluate prosodic-emotional consistency. RLAIF-SPA enables more precise and nuanced control over expressive speech generation along four structured evaluation dimensions: Structure, Emotion, Speed, and Tone. Extensive experiments on Libri-Speech, MELD, and Mandarin ESD datasets demonstrate consistent gains across clean read speech, conversational dialogue, and emotional speech. On Libri-Speech, RLAIF-SPA consistently outperforms Chat-TTS, achieving a 26.1% reduction in word error rate, a 9.1% improvement in SIM-O, and over 10% gains in human subjective evaluations.
Key facts. Cited by 1 paper in the map (data through 14 Oct 2026). Placed in Preference alignment for recommenders and RAG, one of 10 directions in LLM alignment / RLHF / preference optimisation. Builds on 25 of its 34 references that are in the map. First posted on arXiv 16 Oct 2025.
Builds on
25 of 34 references.
Closest ancestors · 2
Same direction, newest first
- 2024SpeechAlign: Aligning Speech Generation to Human Preferences8 Apr
- 2024MusicRL: Aligning Music Generation to Human Preferences6 Feb
Other references · 23
- 2024DeepSeekMath: Pushing the Limits of Mathematical Reasoning in Open Language Modelscited by 9,379
- 2023Direct Preference Optimization: Your Language Model is Secretly a Reward Modelcited by 8,065
- 2022Constitutional AI: Harmlessness from AI Feedbackcited by 3,050
- 2021WavLM: Large-Scale Self-Supervised Pre-Training for Full Stack Speech Processingcited by 1,657
- 2018MELD: A Multimodal Multi-Party Dataset for Emotion Recognition in Conversationscited by 643
- 2023emotion2vec: Self-Supervised Pre-Training for Speech Emotion Representationcited by 205
- 2021Emotional Voice Conversion: Theory, Databases and ESDcited by 115
- 2024EmoBox: Multilingual Multi-corpus Speech Emotion Recognition Toolkit and Benchmarkcited by 40
- 2022EmoDiff: Intensity Controllable Emotional Text-to-Speech with Soft-Label Guidancecited by 37
- 2024Emo-DPO: Controllable Emotional Speech Synthesis through Direct Preference Optimizationcited by 32
- 2019Emotional speech synthesis with rich and granularized controlcited by 28
- 2024EmoSphere-TTS: Emotional Style and Intensity Modeling via Spherical Emotion Vector for Controllable Emotional Text-to-Speechcited by 24
11 more
- 2024Align-SLM: Textless Spoken Language Models with Reinforcement Learning from AI Feedbackcited by 23
- 2023A Vector Quantized Approach for Text to Speech Synthesis on Real-World Spontaneous Speechcited by 22
- 2023EmoMix: Emotion Mixing via Diffusion Models for Emotional Speech Synthesiscited by 19
- 2024Laugh Now Cry Later: Controlling Time-Varying Emotional States of Flow-Matching-Based Zero-Shot Text-to-Speechcited by 19
- 2024ControlSpeech: Towards Simultaneous and Independent Zero-shot Speaker Cloning and Zero-shot Language Style Controlcited by 17
- 2023EmoSpeech: Guiding FastSpeech2 Towards Emotional Text to Speechcited by 15
- 2023ZET-Speech: Zero-shot adaptive Emotion-controllable Text-to-Speech Synthesis with Diffusion and Style-based Modelscited by 14
- 2023MM-TTS: Multi-modal Prompt based Style Transfer for Expressive Text-to-Speech Synthesiscited by 12
- 2025SageLM: A Multi-aspect and Explainable Large Language Model for Speech Judgementcited by 7
- 2025Group Relative Policy Optimization for Text-to-Speech with Large Language Modelscited by 7
- 2024AV-EmoDialog: Chat with Audio-Visual Users Leveraging Emotional Cuescited by 3
Built on by
Citing papers per year: 2026: 1.
1 paper.
Similar, not cited
Close in wording, no citation either way
- 2026Optimizing Conversational Quality in Spoken Dialogue Systems with Reinforcement Learning from AI Feedback
- 2026Bridging What the Model Thinks and How It Speaks: Expressive Speech Generation via Self-Aware Intent-Realization Alignment
- 2026WavAlign: Enhancing Intelligence and Expressiveness in Spoken Dialogue Models via Adaptive Hybrid Post-Training
- 2025Emotion-Aligned Generation in Diffusion Text to Speech Models via Preference-Guided Optimization
- 2026Beyond Speech Captions: Speech-Rewarded Style Planning for Conversational Text-to-Speech
- 2024Re-ENACT: Reinforcement Learning for Emotional Speech Generation using Actor-Critic Strategy
- 2026SpeechEQ: Benchmarking Emotional Intelligence Quotient in Socially Aware Voice Conversational Models
- 2023RLAIF vs. RLHF: Scaling Reinforcement Learning from Human Feedback with AI Feedback