Geintra

Although there has been a lot of interest in
recognizing and understanding Air Traffic Control (ATC)
speech, none of the published works have obtained detailed
field data results. We have developed a system able to identify
the language spoken and recognize and understand sentences
in both Spanish and English. We also present field results for
several in-tower controller positions. To the best of our
knowledge, this is the first time that field ATC speech (not
simulated) is captured, processed and analyzed. The use of
stochastic grammars allows variations in the standard
phraseology that appear in field data. The robust
understanding algorithm developed has 95% concept accuracy
from ATC text input. It also allows changes in the presentation
order of the concepts and the correction of errors created by
the speech recognition engine improving it by 17% and 25%
respectively, absolute in the percentage of fully correctly
understood sentences for English and Spanish in relation to the
percentages of fully correctly recognized sentences. The
analysis of errors due to the spontaneity of the speech and its
comparison to read speech is also carried out. A 96% word
accuracy for read speech is reduced to 86% word accuracy for
field ATC data for Spanish for the “clearances” task
confirming that field data is needed to estimate the
performance of a system. A literature review and a critical
discussion on the possibilities of speech recognition and
understanding technology applied to ATC speech are also
given.