Performance on tests of central auditory processing by individuals exposed to high-intensity blasts

TLDR

Thirty‑six blast‑exposed patients and twenty‑nine controls were evaluated with behavioral and electrophysiological tests sensitive to central auditory processing, and abnormal performance was defined as scores beyond two standard deviations from the control mean. Blast‑exposed patients showed significantly abnormal results on the Gaps‑In‑Noise, Masking Level Difference, and Staggered Spondaic Words tests, as well as on the Quick Speech‑In‑Noise test, indicating that blast exposure can impair hearing in complex auditory environments even when peripheral hearing is near normal.

Abstract

Thirty-six blast-exposed patients and twenty-nine non-blast-exposed control subjects were tested on a battery of behavioral and electrophysiological tests that have been shown to be sensitive to central auditory processing deficits. Abnormal performance among the blast-exposed patients was assessed with reference to normative values established as the mean performance on each test by the control subjects plus or minus two standard deviations. Blast-exposed patients performed abnormally at rates significantly above that which would occur by chance on three of the behavioral tests of central auditory processing: the Gaps-In-Noise, Masking Level Difference, and Staggered Spondaic Words tests. The proportion of blast-exposed patients performing abnormally on a speech-in-noise test (Quick Speech-In-Noise) was also significantly above that expected by chance. These results suggest that, for some patients, blast exposure may lead to difficulties with hearing in complex auditory environments, even when peripheral hearing sensitivity is near normal limits.