Using a commercial speech recogniser within the domain of air traffic control

We have taken an off-the-shelf, commercial continuous speech recogniser and conducted tests using three syntaxes for the domain of Air Traffic Control. The syntaxes are based on a corpus of transmissions between the ATC and pilots and reflect three differing levels of "linguistic" knowledge. The first represented the system where, in effect, there would be no syntax but a lexicon of all words in the corpus. The second took a partial look at syntactic information by using a key phrase spotting mechanism. The third represented the entire syntax of the corpus. Initial experiments show that key phrase spotting is insignificantly more accurate than no syntax at all, whilst use of a complete syntax can improve performance, to a point. The benefits of a discourse grammar are briefly discussed.