RECOVER: Robust Entity Correction via agentic Orchestration of hypothesis Variants for Evidence-based Recovery
This work addresses the challenge of automatic speech recognition (ASR) errors caused by rare or missing domain-specific entities in specialized fields such as finance and healthcare, where post-processing correction is often difficult. The authors propose an agent-based entity correction framework that uniquely integrates ASR n-best hypotheses with tool-augmented large language models (LLMs), leveraging external entity retrieval and constraint-guided decoding for precise error correction. Several hypothesis fusion strategies—including 1-Best, Entity-Aware Select, ROVER Ensemble, and a novel LLM-Select—are introduced to substantially improve entity recall and accuracy. Evaluated across five datasets, the approach achieves relative reductions of 8%–46% in entity word error rate (E-WER) and up to a 22-percentage-point gain in entity recall, while maintaining overall word error rate (WER) stability.