The 1998 BBN BYBLOS Primary System applied to English and Spanish Broadcast News Transcription

In this paper, we describe the BBN BYBLOS system used for the 1998 Hub-4E primary and Hub-4Sp evaluation benchmarks, and discuss the improvements made to the system in 1998. We focus on the techniques that were new in this year’s system, including processing of the acoustic training data, test segmentation, revised cepstral normalization and Vocal Tract Length Normalization (VTLN), band-specific models, Diagonal transform Speaker Adaptive Training (DSAT), and a modified ROVER method for system combination. We show that by combining all the above techniques, we were able to improve the recognition accuracy on the 1997 Hub-4E evaluation test by 27% relative to our 1997 system (from 20.4% to 14.8%). We also present our results on the 1998 Hub-4E and Hub4Sp benchmarks, and discuss the differences between the English and Spanish transcription systems.