8th European Conference on Speech Communication and Technology

Geneva, Switzerland
September 1-4, 2003


Multilingual Acoustic Modeling Using Graphemes

S. Kanthak, Hermann Ney

RWTH Aachen, Germany

In this paper we combine grapheme-based sub-word units with multilingual acoustic modeling. We show that a global decision tree together with automatically generated grapheme questions eliminate manual effort completely. We also investigate the effects of additional language questions.

We present experimental results on four corpora with different languages, namely the Dutch and French ARISE corpus, the Italian EUTRANS corpus and the German VERBMOBIL corpus. Graphemes are shown to give good coverage on all four languages and represent a large set of shared sub-word models. For all experiments, the acoustic models are trained from scratch in order not to use any prior phonetic knowledge.

Finally, we show that for the Dutch and German tasks, the presented approach works well and may also help do decrease the word error rate below that obtained by monolingual acoustic models. For all four languages, adding language questions to the multilingual decision tree helps to improve the word error rate.

Full Paper

Bibliographic reference.  Kanthak, S. / Ney, Hermann (2003): "Multilingual acoustic modeling using graphemes", In EUROSPEECH-2003, 1145-1148.