sEMG Typing Transcription with Conformer Encoding and Beam-Aware Large Language Model Correction

Yuanxi Wang, Lun Shu, Yasuharu Koike


Abstract
Surface electromyography (sEMG) offers a promising path toward private and wearable text input, but accurate typing transcription remains challenging due to strong cross-user and cross-session variability. We propose a beam-aware sEMG typing framework that connects an improved Connectionist Temporal Classification (CTC)-based frontend with a large language model (LLM) corrector for exact recovery of the typed sequence. As a standalone sEMG decoder, our CNN-Conformer frontend achieves the best reported performance among the compared published emg2qwerty systems under the full-session frontend protocol, reaching 19.94% generic character error rate (CER) and 3.43% personalized CER. For LLM correction, we use a separate windowed hypothesis-export protocol, where the frontend’s top-10 CTC hypotheses are provided to a fine-tuned LLM together with a rank-1 baseline. Under this within-protocol comparison, the LLM reduces session-level CER from 22.53% to 19.65% in the generic setting and from 3.41% to 2.01% after personalization. A matched hybrid evaluation further confirms that the LLM also improves rank-1 outputs obtained from full-session decoding. The top-10 oracle results show that the beam contains recoverable information beyond the rank-1 output. These results demonstrate that a stronger sEMG frontend and hypothesis-aware LLM correction can work together effectively for exact sEMG typing transcription.
Anthology ID:
2026.emnlp-main.598
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
13763–13780
Language:
URL:
https://aclanthology.org/2026.emnlp-main.598/
DOI:
Bibkey:
Cite (ACL):
Yuanxi Wang, Lun Shu, and Yasuharu Koike. 2026. sEMG Typing Transcription with Conformer Encoding and Beam-Aware Large Language Model Correction. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 13763–13780, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
sEMG Typing Transcription with Conformer Encoding and Beam-Aware Large Language Model Correction (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.598.pdf