Post-decoder Biasing for End-to-End Speech Recognition of Multi-turn Medical Interview

Heyang Liu, Yanfeng Wang, Yu Wang


Abstract
End-to-end (E2E) approach is gradually replacing hybrid models for automatic speech recognition (ASR) tasks. However, the optimization of E2E models lacks an intuitive method for handling decoding shifts, especially in scenarios with a large number of domain-specific rare words that hold specific important meanings. Furthermore, the absence of knowledge-intensive speech datasets in academia has been a significant limiting factor, and the commonly used speech corpora exhibit significant disparities with realistic conversation. To address these challenges, we present Medical Interview (MED-IT), a multi-turn consultation speech dataset that contains a substantial number of knowledge-intensive named entities. We also explore methods to enhance the recognition performance of rare words for E2E models. We propose a novel approach, post-decoder biasing, which constructs a transform probability matrix based on the distribution of training transcriptions. This guides the model to prioritize recognizing words in the biasing list. In our experiments, for subsets of rare words appearing in the training speech between 10 and 20 times, and between 1 and 5 times, the proposed method achieves a relative improvement of 9.3% and 5.1%, respectively.
Anthology ID:
2024.lrec-main.1131
Volume:
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Month:
May
Year:
2024
Address:
Torino, Italia
Editors:
Nicoletta Calzolari, Min-Yen Kan, Veronique Hoste, Alessandro Lenci, Sakriani Sakti, Nianwen Xue
Venues:
LREC | COLING
SIG:
Publisher:
ELRA and ICCL
Note:
Pages:
12917–12926
Language:
URL:
https://aclanthology.org/2024.lrec-main.1131
DOI:
Bibkey:
Cite (ACL):
Heyang Liu, Yanfeng Wang, and Yu Wang. 2024. Post-decoder Biasing for End-to-End Speech Recognition of Multi-turn Medical Interview. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), pages 12917–12926, Torino, Italia. ELRA and ICCL.
Cite (Informal):
Post-decoder Biasing for End-to-End Speech Recognition of Multi-turn Medical Interview (Liu et al., LREC-COLING 2024)
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PDF:
https://aclanthology.org/2024.lrec-main.1131.pdf