THE LIMSI 2006 TC-STAR TRANSCRIPTION SYSTEMS ⁄

Published in the Tc-Star Speech to Speech Translation Workshop, Barcelona, pages 123n128, June 2006. This paper describes the speech recognizers evaluated in the TC-STAR Second Evaluation Campaign held in JanuaryFebruary 2006. Systems were developed to transcribe parliamentary speeches in English and Spanish, as well as Broadcast news in Mandarin Chinese. The speech recognizers are state-of-the-art systems using multiple decoding passes with models (lexicon, acoustic models, language models) trained for the different transcription tasks. Compared to the LIMSI TC-STAR 2005 European Parliament Plenary Sessions (EPPS) systems, relative word error rate reductions of about 30% have been achieved on the 2006 development data. The word error rates with the LIMSI systems on the 2006 EPPS evaluation data are 8.2% for English and 7.8% for Spanish. The character error rate for Mandarin for a joint system submission with the University of Karlsruhe was 9.8%. Experiments with cross-site adaptation and system combination are also described.