Graduation Year


Document Type




Degree Granting Department


Major Professor

Richard A. Roberts, Ph.D. Chair

Co-Major Professor

K. Paul Boyev, M.D. Co-Chair

Committee Member

Harvey B. Abrams, Ph.D.

Committee Member

Raymond Hurley, Ph.D.

Committee Member

Jennifer Lister, Ph.D.


temporary threshold shift, TTS, permanent threshold shift, PTS, supplemental magnesium, noise induced hearing loss


Previous literature has demonstrated that supplemental magnesium may have a prophylactic effect on noise induced hearing loss (NIHL). The purpose of this study was to replicate the findings of a previous investigation concerning the beneficial effects of supplemental magnesium on TTS in humans. Forty participants with normal hearing were divided into two groups, experimental and control. The experimental group received a single, 150 mg dose of supplemental magnesium and the control group received a placebo. After an hour in a quiet environment, all participants were exposed to a narrowband noise centered at 2000 Hz and presented at 105 dB SPL. Audiometric thresholds were measured for the frequency range 250 Hz - 8000 Hz prior to the noise exposure, and then immediately, 30 minutes, and 60 minutes post-noise exposure. Both groups experienced TTS at and above 2000 Hz. The largest TTS was observed immediately following the noise exposure in both groups. There was no significant difference in TTS between the experimental group and the control group. It was concluded that a single dose of 150 mg of supplemental magnesium was not effective in reducing or preventing TTS.