Adversarial Data Augmentation for Disordered Speech Recognition
This work addresses the problem of limited data for automatic speech recognition in individuals with neuro-motor conditions like dysarthria, offering an incremental improvement over existing augmentation techniques.
The paper tackled the challenge of recognizing disordered speech by proposing an adversarial data augmentation method that models fine-grained spectro-temporal differences, achieving a 3.05% absolute WER reduction (9.7% relative) over a baseline with no augmentation and a final WER of 25.89% on the UASpeech test set.
Automatic recognition of disordered speech remains a highly challenging task to date. The underlying neuro-motor conditions, often compounded with co-occurring physical disabilities, lead to the difficulty in collecting large quantities of impaired speech required for ASR system development. To this end, data augmentation techniques play a vital role in current disordered speech recognition systems. In contrast to existing data augmentation techniques only modifying the speaking rate or overall shape of spectral contour, fine-grained spectro-temporal differences between disordered and normal speech are modelled using deep convolutional generative adversarial networks (DCGAN) during data augmentation to modify normal speech spectra into those closer to disordered speech. Experiments conducted on the UASpeech corpus suggest the proposed adversarial data augmentation approach consistently outperformed the baseline augmentation methods using tempo or speed perturbation on a state-of-the-art hybrid DNN system. An overall word error rate (WER) reduction up to 3.05\% (9.7\% relative) was obtained over the baseline system using no data augmentation. The final learning hidden unit contribution (LHUC) speaker adapted system using the best adversarial augmentation approach gives an overall WER of 25.89% on the UASpeech test set of 16 dysarthric speakers.