用束搜索信息提升语音识别置信度,效果优于传统方法。
Leveraging Beam Search Information for Confidence Estimation in E2E ASR

- 基于束搜索中的得分与排名构造置信度特征
- 词级最大校准误差降至8.17%,显著低于软最大值法
- 适用于多种模型架构和语音场景,通用性强
为估计端到端语音识别(ASR)系统的置信度,现有研究多依赖骨干模型特征,但通常与架构绑定。本文提出轻量级的评分-排序置信度估计模块(SR-CEM),利用束搜索中候选序列的得分与排名生成词元和词汇级置信度。实验表明,该方法在英语域内和域外数据上均表现良好:在域内测试集上,词元级最大校准误差为4.50%,期望校准误差为0.30%,显著优于软最大值置信度(20.04%和1.75%);词级分别为8.17%和0.35%,优于软最大值的17.91%和1.67%。此外,其在混合型与转换器型架构、不同解码策略及荷兰语、嘈杂语音和对话式语音等条件下均保持鲁棒性,尤其有效降低最大校准误差,且不依赖特定架构,具有广泛适用性。
原文摘要 · Abstract (English)
To estimate confidence for end-to-end Automatic Speech Recognition (ASR) systems, recent research has proposed Confidence Estimation Modules that incorporate features from the backbone ASR model. Most existing approaches, however, are architecture-dependent. In this paper, we propose the Score-Rank Confidence Estimation Module (SR-CEM), a lightweight module that leverages beam search information to generate token- and word-level confidence scores. Specifically, SR-CEM constructs features by combining the scores and ranks of tokens within a hypothesis. Experiments show that SR-CEM achieves effective calibration on both in-domain and out-of-domain English data. On the in-domain testset, it attains a Maximum Calibration Error of 4.50% and an Expected Calibration Error of 0.30% at the token level, significantly outperforming softmax confidence (20.04% and 1.75%, respectively). At the word level, SR-CEM achieves 8.17% and 0.35%, compared to 17.91% and 1.67% from softmax confidence. Furthermore, we demonstrate its robustness across hybrid and transducer ASR architectures with different decoding strategies, as well as on Dutch, noisy and conversational speech conditions. Our main finding is that SR-CEM is particularly effective in reducing Maximum Calibration Error, which is critical for reliable downstream use of ASR outputs, while maintaining architecture independence and generality across diverse evaluation conditions.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。