The effects of information load and speech rate on younger and older aircraft pilots' ability to execute simulated air-traffic controller instructions.

In this applied study of memory for orally presented information, 15 younger and 15 older pilots heard recorded air-traffic controller (ATC) messages in the context of six simulated flights. The ATC messages varied in length (3 vs 4 items), speech rate (235 vs 365 wpm), and type of command (course commands consisting of headings and altitudes vs radio/transponder commands consisting of radio frequencies and transponder codes). Older pilots made more execution errors on average and the age difference was greater for the radio/transponder commands, which contained more unique digits than the course commands. Although longer message lengths and faster speech rates led to higher error rates, the increases were not more marked in the older group. Backward digit span was correlated with communication performance, but the older group's lower level of accuracy was not explainable in terms of differences in digit span.