Semi-Supervision in ASR: Sequential Mixmatch and Factorized TTS-Based Augmentation

Zhehuai Chen
Yu Zhang
Yinghui Huang
Jesse Emond
Bhuvana Ramabhadran
Pedro Jose Moreno Mengibar


Semi- and self-supervised training techniques have the potential to improve performance of speech recognition systems without additional transcribed speech data. In this work, we demonstrate the efficacy of two approaches to semi-supervision for automated speech recognition. The two approaches lever-age vast amounts of available unspoken text and untranscribed audio. First, we present factorized multilingual speech synthesis to improve data augmentation on unspoken text. Next, we present an online implementation of Noisy Student Training to incorporate untranscribed audio. We propose a modified Sequential MixMatch algorithm with iterative learning to learn from untranscribed speech. We demonstrate the compatibility of these techniques yielding a relative reduction of word error rate of up to 14.4% on the voice search task.

Research Areas