Grapheme and Multilingual Posterior Features for Under-Resourced Speech Recognition: A Study on Scottish Gaelic
Standard automatic speech recognition (ASR) systems use phonemes as subword units. Thus, one of the primary resource required to build a good ASR system is a well developed phoneme pronunciation lexicon. However, under-resourced languages typically lack such lexical resources. In this paper, we investigate recently proposed grapheme-based ASR in the framework of Kullback-Leibler divergence based hidden Markov model (KL-HMM) for under-resourced languages, particularly Scottish Gaelic which has no lexical resources. More specifically, we study the use of grapheme and multilingual phoneme class conditional probabilities (posterior features) as feature observations in KL-HMM. ASR studies conducted show that the proposed approach yields better system compared to the conventional HMM/GMM approach using cepstral features. Furthermore, grapheme posterior features estimated using both auxiliary data and Gaelic data yield the best system.
Rasipuram_ICASSP-2_2013.pdf
openaccess
70.53 KB
Adobe PDF
45a12d32a64f40e8bb477c8e27de4b9a