The Vocapia Research ASR Systems for EVALITA 2011

摘要

This document describes the automatic speech-to-text transcription used by Vocapia Research for the EVALITA 2011 evaluation for the open unconstrained automatic speech recognition (ASR) task. The aim of this evaluation was to perform automatic speech recognition of parliament audio sessions in the Italian language. About 30h of untran-scribed audio data and one year of minutes from parliament sessions were provided as training corpus. This corpus was used to carry out an unsupervised adaptation of Vocapia's Italian broadcast speech transcription system. Transcriptions produced by two systems were submitted. The primary system has a single decoding pass and was optimized to run in real time. The contrastive system, developed in collaboration with LIMSI-CNRS, has two decoding passes and runs in about 5×RT. The case-insensitive word error rates (WER) of these systems are respectively 10.2% and 9.3% on the EVALITA development data and 6.4% and 5.4% on the evaluation data.