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Lynne Marshall, Judi Lapsley Miller, Laurie Heller, Linda Hughes, & Linda
Westhusin
January 2002
Poster presentation at the 2002 ARO conference
Assoc. Res. Otolaryngol Abs. 25.
Abstract
Evoked otoacoustic emissions and hearing thresholds were measured in 339
sailors from the USS Dwight D. Eisenhower aircraft carrier before and after a
six-month deployment to the Mediterranean. Sailors from the Air, Reactor, and
Engineering departments were targeted because they were considered most at risk
for noise-induced hearing loss. At pre-deployment and post-deployment testing,
hearing thresholds (0.5 to 6 kHz) were measured using a modified
Hughson-Westlake procedure and normal middle-ear pressure was established.
Transient-evoked otoacoustic emissions (non-linear click stimulus at 74 dB pSPL)
and distortion-product otoacoustic emissions (f2/f1=1.22, at four stimulus
levels) were then measured using the Otodynamics ILO292 Echoport. There was no
consistent change in average hearing thresholds for the group; however, some
individuals showed significant threshold shifts. Temporary threshold shifts were
confirmed for two sailors (two ears) and permanent threshold shifts were
confirmed for fifteen sailors (eighteen ears), based on their noise history and
a confirmatory audiogram. Some additional significant threshold shifts were
unable to be confirmed. Preliminary group results indicated that after
deployment there was a decrease in average distortion-product and
transient-evoked otoacoustic-emission amplitudes. Changes in
otoacoustic-emission amplitudes might be a more sensitive indicator of
noise-induced damage to the inner ear than changes in hearing thresholds.
View poster in pdf format
Last updated
08 Nov 2009 04:37 PM
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