[The protective effect of oral magnesium supplement on noise-induced hearing loss]

We investigated the beneficial effect of magnesium in the prevention of noise-induced cochlear damage in guinea pigs by transient evoked otoacoustic emissions (TEOAE).

Thirty-nine guinea pigs with normal auropalpebral reflex were randomly divided into control (n=20) and study (n=19) groups. All the animals were subjected to wide-band noise standardized at a mean of 98+/-2 dB for 16 hours a day for 10 days in a sound isolated cabin. The study animals received 39 mmol/l MgCl2 throughout the study period starting from 15 days before noise exposure. Otomicroscopic examination, auditory brain stem response (ABR) and TEOAE measurements were performed before and after noise exposure. Tympanometric measurements were performed to eliminate possible middle ear pathologies.

Although the mean TEOAE response and reproducibility values showed significant decreases after noise application in the control group (p<0.001), they were not affected significantly in magnesium-treated animals. Post-exposure mean TEOAE response and reproducibility values significantly differed between the two groups (p<0.001). Noise-induced elevations in ABR thresholds were significant in both groups (p<0.001); however, it was noted that hearing levels were better preserved in the study group.

Our data suggest that oral magnesium intake may be beneficial in the prevention of cochlear damage in noise-induced hearing loss.