Developments in continuous speech dictation using the ARPA WSJ task

We report on our recent development work in large vocabulary, American English continuous speech dictation. We have experimented with (1) alternative analyses for the acoustic front end, (2) the use of an enlarged vocabulary so as to reduce the number of errors due to out-of-vocabulary words, (3) extensions to the lexical representation, (4) the use of additional acoustic training data, and (5) modification of the acoustic models for telephone speech. The recognizer was evaluated on Hubs 1 and 2 of the fall 1994 ARPA NAB CSR Hub and Spoke Benchmark test. Experimental results for development and evaluation test data are given, as well as an analysis of the errors on the development data.