Bridging ASR and LLMs for Dysarthric Speech Recognition: Benchmarking Self-Supervised and Generative Approaches
This study addresses the severe phoneme distortions and high inter-speaker variability in dysarthric speech, which drastically degrade automatic speech recognition (ASR) performance. We propose a novel collaborative decoding paradigm integrating self-supervised speech models with large language models (LLMs). Specifically, we jointly leverage front-end acoustic models—including Wav2Vec 2.0, HuBERT, and Whisper—with both CTC and sequence-to-sequence outputs; backend constrained decoding is performed using LLMs (BART, GPT-2, and Vicuna) to restore phonemes and enforce syntactic and semantic consistency. Extensive experiments across multiple severity levels and cross-dataset benchmarks (e.g., UA-Speech, TORGO) demonstrate that LLM-augmented decoding significantly improves word error rate (WER) and intelligibility—achieving up to a 23.6% relative reduction in WER for severely dysarthric speech over baseline ASR systems—while markedly enhancing generalization and robustness. To our knowledge, this is the first systematic investigation validating the critical role of LLMs in joint semantic–acoustic modeling of dysarthric speech.