Evaluating grapheme-to-phoneme converters in automatic speech recognition context

Denis Jouvet (1) , Dominique Fohr (1) , Irina Illina (1)

1 PAROLE - Analysis, perception and recognition of speech

This paper deals with the evaluation of grapheme-to-phoneme (G2P) converters in a speech recognition context. The precision and recall rates are investigated as potential measures of the quality of the multiple generated pronunciation variants. Very different results are obtained whether or not we take into account the frequency of occurrence of the words. Since G2P systems are rarely evaluated on a speech recognition performance basis, the originality of this paper consists in using a speech recognition system to evaluate the G2P pronunciation variants. The results show that the training process is quite robust to some errors in the pronunciation lexicon, whereas pronunciation lexicon errors are harmful in the decoding process. Noticeable speech recognition performance improvements are achieved by combining two different G2P converters, one based on conditional random fields and the other on joint multigram models, as well as by checking the pronunciation variants of the most frequent words.

Mots clés: Grapheme-to-phoneme; pronunciation lexicon; speech recognition

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Denis Jouvet, Dominique Fohr, Irina Illina. Evaluating grapheme-to-phoneme converters in automatic speech recognition context. ICASSP - 2012 - IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Mar 2012, Kyoto, Japan. pp.4821 - 4824, ⟨10.1109/ICASSP.2012.6288998⟩. ⟨hal-00753364⟩