Short-duration space flight and hearing loss.
OBJECTIVE
The study goal was to determine whether a single Space Shuttle mission can induce decrements in astronaut hearing. Study design We retrospectively compared audiogram information obtained from Space Shuttle astronauts at 10 days preflight, day of return (R + 0), 3 days after landing return (R + 3), and at a mean delayed postflight follow-up of 8 months.


RESULTS
Temporary threshold shift (mean, 4.6 dB) was noted in R + 0 versus preflight conditions (P < 0.01). Small permanent threshold shifts (mean, 0.83 dB) were found at R + 3 and postflight follow-up compared with preflight in the lower frequencies (500 to 2000 Hz), and corresponding pure tone average (P < 0.001). Conclusions and significance The data indicate that a single Shuttle flight can induce a substantial temporary threshold shift and a small but statistically significant permanent threshold shift, particularly in the frequencies involved in speech reception. Although single-mission effects are small, cumulative effects over several missions may ultimately produce clinically significant hearing loss.
Roller
Carrie A
CA
Bobby R Alford Department of Otorhinolaryngology, Baylor College of Medicine, USA. croller@bcm.tmc.edu
Clark
Jonathan B
JB
D001299:Audiometry; D001309:Auditory Threshold / Q000502:physiology*; D004430:Ear Protective Devices; D006312:Hearing Loss, Bilateral / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D012189:Retrospective Studies; D013026:Space Flight; D013997:Time Factors