A Neural Model for Contextual Biasing Score Learning and Filtering

Fuente: arXiv
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Main Authors: Huang, Wanting, Wang, Weiran
Format: Preprint
Published: 2025
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author Huang, Wanting
Wang, Weiran
author_facet Huang, Wanting
Wang, Weiran
contents Contextual biasing improves automatic speech recognition (ASR) by integrating external knowledge, such as user-specific phrases or entities, during decoding. In this work, we use an attention-based biasing decoder to produce scores for candidate phrases based on acoustic information extracted by an ASR encoder, which can be used to filter out unlikely phrases and to calculate bonus for shallow-fusion biasing. We introduce a per-token discriminative objective that encourages higher scores for ground-truth phrases while suppressing distractors. Experiments on the Librispeech biasing benchmark show that our method effectively filters out majority of the candidate phrases, and significantly improves recognition accuracy under different biasing conditions when the scores are used in shallow fusion biasing. Our approach is modular and can be used with any ASR system, and the filtering mechanism can potentially boost performance of other biasing methods.
format Preprint
id arxiv_https___arxiv_org_abs_2510_23849
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Neural Model for Contextual Biasing Score Learning and Filtering
Huang, Wanting
Wang, Weiran
Audio and Speech Processing
Artificial Intelligence
Computation and Language
Sound
Contextual biasing improves automatic speech recognition (ASR) by integrating external knowledge, such as user-specific phrases or entities, during decoding. In this work, we use an attention-based biasing decoder to produce scores for candidate phrases based on acoustic information extracted by an ASR encoder, which can be used to filter out unlikely phrases and to calculate bonus for shallow-fusion biasing. We introduce a per-token discriminative objective that encourages higher scores for ground-truth phrases while suppressing distractors. Experiments on the Librispeech biasing benchmark show that our method effectively filters out majority of the candidate phrases, and significantly improves recognition accuracy under different biasing conditions when the scores are used in shallow fusion biasing. Our approach is modular and can be used with any ASR system, and the filtering mechanism can potentially boost performance of other biasing methods.
title A Neural Model for Contextual Biasing Score Learning and Filtering
topic Audio and Speech Processing
Artificial Intelligence
Computation and Language
Sound
url https://arxiv.org/abs/2510.23849