Short‐duration space flight and hearing loss

Abstract

OBJECTIVES: 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.

Hals, Nase und Ohren in der Schwerelosigkeit: die kosmischen Herausforderungen der HNO-Heilkunde

“…Auch das Hörvermögen bleibt nicht von den Auswirkungen der Raumfahrt verschont. Ein Vergleich der Hörschwelle vor und nach dem Raumflug zeigt, ungeachtet der Dauer, bei fast allen Astronauten eine vorübergehende Verschiebung der Hörschwelle [21,22]. Teils waren die entstandenen Hörschäden bleibend und führten in Einzelfällen sogar zur Flugunfähigkeit der betroffenen Astronauten [23].…”

Hearing Loss in Space Flights: A Review of Noise Regulations and Previous Outcomes

“…Nevertheless, PTSs were deemed concerning by the authors since they were detected even after a single, brief mission that lasted an average of 9 days and occurred at frequencies associated with the perception of human speech. 9 Overall, sound pressure levels for the space shuttle were measured to be 118 dB internally and 149 dB externally. Hearing protection devices were used for protection at these short-term exposures.…”