As human-machine voice interfaces provide easy access to increasingly intelligent machines, many state-of-the-art automatic speech recognition (ASR) systems are proposed. However, commercial ASR systems usually have poor performance on domain-specific speech especially under low-resource settings. The author works with pre-trained DeepSpeech2 and Wav2Vec2 acoustic models to develop benefit-specific ASR systems. The domain-specific data are collected using proposed semi-supervised learning annotation with little human intervention. The best performance comes from a fine-tuned Wav2Vec2-Large-LV60 acoustic model with an external KenLM, which surpasses the Google and AWS ASR systems on benefit-specific speech. The viability of using error prone ASR transcriptions as part of spoken language understanding (SLU) is also investigated. Results of a benefit-specific natural language understanding (NLU) task show that the domain-specific fine-tuned ASR system can outperform the commercial ASR systems even when its transcriptions have higher word error rate (WER), and the results between fine-tuned ASR and human transcriptions are similar.

使用预训练的DeepSpeech2和Wav2Vec2声学模型，提出了基于领域的语音自动识别系统，并通过半监督机器注释的方式收集领域特定的数据，研究结果表明，该系统即使在具有更高的字词错误率的情况下，性能仍优于商业自动语音识别系统，且在人工转录的结果上也呈现出类似的效果。同时，也探讨了使用自动语音识别文字转录来辅助口语理解的可行性。

面向特定领域语音识别的深度学习系统