Title
Neural Candidate-Aware Language Models For Speech Recognition
Abstract
This paper presents novel neural network based language models that can correct automatic speech recognition (ASR) errors by using speech recognizer outputs as a context. Our proposed models, called neural candidate-aware language models (NCALMs), estimate the generative probability of a target sentence while considering ASR outputs including hypotheses and their posterior probabilities. Recently, neural network language models have achieved great success in ASR field because of their ability to learn long-range contexts and model the word representation in continuous space. However, they estimate a sentence probability without considering other candidates and their posterior probabilities, even though the competing hypotheses are available and include important information to increase the speech recognition accuracy. To overcome this limitation, our idea is to utilize ASR outputs in both the training phase and the inference phase. Our proposed models are conditional generative models consisting of a Transformer encoder and a Transformer decoder. The encoder embeds the candidates as context vectors and the decoder estimates a sentence probability given the context vectors. We evaluate the proposed models in Japanese lecture transcription and English conversational speech recognition tasks. Experimental results show that a NCALM has better ASR performance than a system including a deep neural network-hidden Markov model hybrid system. We further improve ASR performance by using a NCALM and a Transformer language model simultaneously. (C) 2020 Published by Elsevier Ltd.
Year
DOI
Venue
2021
10.1016/j.csl.2020.101157
COMPUTER SPEECH AND LANGUAGE
Keywords
DocType
Volume
Automatic speech recognition, Neural network language models, Rescoring hypotheses, Conditional generative language models
Journal
66
ISSN
Citations 
PageRank 
0885-2308
0
0.34
References 
Authors
0
3
Name
Order
Citations
PageRank
Tomohiro Tanaka155.11
Ryo Masumura22528.24
Takanobu Oba35312.09