Clinical Trial: Micronutrients to Prevent Noise-induced Hearing Loss

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Micronutrient Intervention to Reduce Noise-Induced Hearing Loss: Prevention of Temporary Threshold Changes Induced by Use of a Digital Music Player

Brief Summary:

Noise-induced hearing loss (NIHL) is a significant clinical, social, and economic issue. Studies in animals have allowed us to identify mechanisms contributing to NIHL, including direct mechanical trauma, free radicals formed in association with metabolic stress, and reduced blood flow. A combination of antioxidant vitamins (beta-carotene, and vitamins C and E) and the mineral magnesium (which acts in part as a vasodilator but also as an antioxidant) is highly effective in preventing NIHL in animals. These studies evaluate efficacy of this intervention in humans.

Hypothesis: Treatment with these micronutrients provides safe, effective attenuation of acute hearing changes induced by exposure to real-world sounds producing temporary (non-permanent) or permanent hearing changes induced by exposure to real-world sounds.

Experiment 1: "Digital Audio Player" studies (University of Florida, Gainesville). Prevention of *temporary* elevations in hearing thresholds, induced by exposure to moderately loud music, will be measured. Subjects will be 70 young adults with equal numbers of male and female participants.


Detailed Summary: This study assessed the potential for prevention of the temporary changes in hearing that can occur after use of a music player device for 4 hours. All participants listened to one of two playlists (pop or rock) set at the same volumes to provide equivalent and consistent exposures across participants. Participants received either a dietary supplement or a placebo once/daily for three days prior to the day of music exposure, and also on the day of music exposure. The fourth and final dose was consumed immediately prior to music listening and consumption was observed by a member of the study team. Changes in hearing were assessed 15-min post-music, and then 1, 2, and 3 hours later, as well as the following day and 1 week later.
Sponsor: University of Michigan

Current Primary Outcome: Average Threshold Shift at 4 kHz in Both Ears [ Time Frame: 15 min, 1 hr intervals for 3 hours to measure temporary changes; additional tests at 1 day and 1 week post-exposure. ]

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.


Original Primary Outcome: Maximum threshold shift at 3, 4, or 6 kHz in either ear [ Time Frame: 15 min, repeated measures at 1-1.5 hr intervals for 3-3.5 hours to measure temporary changes. Tests at 1 year and 2 years to measure permanent changes in Spanish studies. ]

Current Secondary Outcome:

  • Threshold Shift at Individual Frequencies, Including 0.25, 0.5, 1, 2, 3, 6, and 8 kHz, 15 Min Post-music [ Time Frame: 15 min ]
    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.
  • Tinnitus [ Time Frame: immediate, repeated measures at 1 hr intervals for 3 hours to measure temporary changes; additional tests at 1 day and 1 week post-exposure. ]
    Presence of tinnitus was assessed using yes/no question. If tinnitus was reported, perception was assessed using survey.


Original Secondary Outcome:

  • Threshold shift at individual frequencies, including 0.25, 0.5, 1, 2, 3, 4, 6, 8, 10, 12.5, 14 and 16 kHz [ Time Frame: 15 min, repeated measures at 1-1.5 hr intervals for 3-3.5 hours to measure temporary changes. Tests at 1 year and 2 years to measure permanent changes in Spanish studies. ]
  • Distortion Product Otoacoustic Emission (DPOAE) amplitude [ Time Frame: 15 min, repeated measures at 1-1.5 hr intervals for 3-3.5 hours to measure temporary changes. Tests at 1 year and 2 years to measure permanent changes in Spanish studies. ]
  • Tinnitus [ Time Frame: 15 min, repeated measures at 1-1.5 hr intervals for 3-3.5 hours to measure temporary changes. Tests at 1 year and 2 years to measure permanent changes in Spanish studies. ]


Information By: University of Michigan

Dates:
Date Received: December 11, 2008
Date Started: October 2008
Date Completion:
Last Updated: April 13, 2017
Last Verified: April 2017