JCAB English Test and ATC Communications Speech Speeds (岡野H.圭一教授 退職記念号)

We measured the speech speed rate in the listening comprehension section of the Japanese Language Proficiency Certification test for pilots as established by the Japanese Civil Aviation Bureau in conformance with the requirements of the International Civil Aviation Organization, and found a median of 4.5 syllables per second. We compare this rate with the median of 6.1 syllables per second in actual ATC communications and of 5.1 and 4.7 syllables per second respectively in movies and TV news which we determined in previous studies, and of 5-7 syllables per second in typical everyday speech. We conclude that the pilot test and the ICAO recommendations are slower than speaking rates in real-life situations. We note that in a previous study we found that errors in listening to TV show sentences increased 5-fold between 4 syllables per second and 6 syllables per second, so that even very highly-rated non-native speakers of English missed 21.2％ of the words at 6 syllables per second and 32.7% at 7 syllables per second, despite repeated listening. We express our concern that even highly-rated pilots will similarly perform poorly in listening to fast speech. We call for further studies on the effects of increasing speech rates on the listening ability of pilots, in order to contribute to the development of training material and safer air travel.