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Speaker adaptation and adaptive training for jointly optimised tandem systems

Accepted version
Peer-reviewed

Type

Conference Object

Change log

Authors

Wang, Y 
Zhang, C 
Gales, MJF 
Woodland, PC 

Abstract

Speaker independent (SI) Tandem systems trained by joint optimisation of bottleneck (BN) deep neural networks (DNNs) and Gaussian mixture models (GMMs) have been found to produce similar word error rates (WERs) to Hybrid DNN systems. A key advantage of using GMMs is that existing speaker adaptation methods, such as maximum likelihood linear regression (MLLR), can be used which to account for diverse speaker variations and improve system robustness. This paper investigates speaker adaptation and adaptive training (SAT) schemes for jointly optimised Tandem systems. Adaptation techniques investigated include constrained MLLR (CMLLR) transforms based on BN features for SAT as well as MLLR and parameterised sigmoid functions for unsupervised test-time adaptation. Experiments using English multi-genre broadcast (MGB3) data show that CMLLR SAT yields a 4% relative WER reduction over jointly trained Tandem and Hybrid SI systems, and further reductions in WER are obtained by system combination.

Description

Keywords

Speech recognition, Tandem system, joint training, speaker adaptive training

Journal Title

Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH

Conference Name

Interspeech 2018

Journal ISSN

2308-457X
1990-9772

Volume Title

2018-September

Publisher

ISCA