Micronutrients to Prevent Noise-induced Hearing Loss

The study measures the quietest decibel level the participants can hear before the 4 hour music exposure The first post-music test to measure shift is 15 minutes after the music exposure is completed and again at 1 hour intervals. The shift represents the mean change in quietest decibel volume detected between baseline (pre-music) and post music.

The study measures the quietest decibel level the participants can hear before the 4 hour music exposure The first post-music test to measure shift is 15 minutes after the music exposure is completed and again at 1 hour intervals. The shift represents the mean change in quietest decibel volume detected between baseline (pre-music) and post music.

Presence of tinnitus was assessed using yes/no question. If tinnitus was reported, perception was assessed using survey.

DPOAE amplitude was measured following the audiometric testing completion at approximately 30 minutes post music. Test time was approximate as DPOAE tests began as soon as threshold testing was completed. F1 and F2 frequency pairs included 3328 and 3984 Hz, F1 sound levels started at 65 dB SPL at each frequency, and decreased in 5 dB steps to a level of 25 dB SPL. F2 levels were 10 dB lower than F1 levels. Threshold tests began precisely at 15 min, 1 hr 15 min, 2 hr 15 min, 3 hr 15 min. Threshold tests take approximately 15 min, but the exact duration of testing varies from subject to subject. The OAE testing began as soon as threshold testing completed. Thus, OAE tests began approx. 30 min, 1 hr 30 min, 2 hr 30 min, and 3 hr 30 min post music, but for some it may have been a little bit earlier or a little bit later (i.e., the test may have begun as early as 25 min or as late as 35 min post music, depending on how quickly the subject completed threshold testing).

DPOAE amplitude was measured following the audiometric testing completion at each of the post-music test times. F1 and F2 frequency pairs included 6656 and 8015 Hz, 5016 and 6000 Hz, 3328 and 3984 Hz, 2484 and 3000 Hz, and 1687 and 2015 Hz. F1 sound levels started at 65 dB SPL at each frequency, and decreased in 5 dB steps to a level of 25 dB SPL. F2 levels were 10 dB lower than F1 levels.

Distortion Product Otoacoustic Emission (DPOAE) Amplitude was measured following the audiometric testing completion at approximately 30 minutes post music. F1 and F2 frequency pairs included 6656 and 8015 Hz, 5016 and 6000 Hz, 2484 and 3000 Hz, and 1687 and 2015 Hz. F1 sound levels started at 65 dB SPL at each frequency, and decreased in 5 dB steps to a level of 25 dB SPL. F2 levels were 10dB lower than F1 Levels. Threshold tests began precisely at 15 min, 1 hr 15 min, 2 hr 15 min, 3 hr 15 min. The OAE testing began as soon as threshold testing completed. Threshold tests take approximately 15 min, but the exact duration of testing varies among subjects. Thus, OAE tests began approx. 30 min, 1 hr 30 min, 2 hr 30 min, and 3 hr 30 min post music, but for some it may have been a little bit earlier than for others (i.e., the test may have begun as early as 25 min or as late as 35 min post music, depending on how quickly the subject completed threshold testing).