论文标题
IARPA OpenASR21挑战的Thuee系统描述
The THUEE System Description for the IARPA OpenASR21 Challenge
论文作者
论文摘要
本文介绍了Thuee团队对IARPA开放自动语音识别挑战（OpenASR21）的语音识别系统，并进行了进一步的实验探索。我们在受约束和约束训练条件下取得了出色的结果。对于受限的训练条件，我们基于标准混合体系结构构建基本ASR系统。为了减轻量不计（OOV）的问题，我们使用针对OOV和潜在的新单词的素式至phoneme（G2P）技术扩展了发音词典。采用了标准的声学模型结构，例如CNN-TDNN-F和CNN-TDNN-F-A。此外，还应用了多种数据增强技术。对于约束训练条件，我们使用自我监督的学习框架WAV2VEC2.0。我们在公开可用的预训练型XLSR-53的基础上使用连接式时间分类（CTC）标准进行各种微调技术。我们发现，在将WAV2VEC2.0预训练的模型应用于基于编码器的CTC/CTC/COATION ASR体系结构时，前端特征提取器在将WAV2VEC2.0预训练的模型应用时起着重要作用。通过将目标语言用作为前端功能提取器使用的CTC模型填充可以实现额外的改进。
This paper describes the THUEE team's speech recognition system for the IARPA Open Automatic Speech Recognition Challenge (OpenASR21), with further experiment explorations. We achieve outstanding results under both the Constrained and Constrained-plus training conditions. For the Constrained training condition, we construct our basic ASR system based on the standard hybrid architecture. To alleviate the Out-Of-Vocabulary (OOV) problem, we extend the pronunciation lexicon using Grapheme-to-Phoneme (G2P) techniques for both OOV and potential new words. Standard acoustic model structures such as CNN-TDNN-F and CNN-TDNN-F-A are adopted. In addition, multiple data augmentation techniques are applied. For the Constrained-plus training condition, we use the self-supervised learning framework wav2vec2.0. We experiment with various fine-tuning techniques with the Connectionist Temporal Classification (CTC) criterion on top of the publicly available pre-trained model XLSR-53. We find that the frontend feature extractor plays an important role when applying the wav2vec2.0 pre-trained model to the encoder-decoder based CTC/Attention ASR architecture. Extra improvements can be achieved by using the CTC model finetuned in the target language as the frontend feature extractor.
