THE LIMSI 2006 TC-STAR TRANSCRIPTION SYSTEMS

Abstract

This paper describes the speech recognizers evaluated in the TC-STAR Second Evaluation Campaign held in January-February 2006. Systems were developed to transcribe parliamentary speeches in English and Spanish, as well as Broadcast news in Mandarin Chinese. The speech recognizers are stateof-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.