Gedik O, Doğan R, Babademez MA, et al. - Researchers sought to determine the healing effect of metformin on noise-induced hearing loss (NIHL) by measuring audiological, biochemical and histological parameters. They grouped 32 rats into four groups (Group 1: Noise, Group 2: Noise + Metformin, Group 3: Metformin, Group 4: Control). In Group 2, Auditory Brainstem Response (ABR) thresholds decrease significantly on day 7 and day 14 compared with day 1; significantly higher distortion product otoacoustic emission values on the 7th and 14th days were reported than the postnoise levels. Group 1 exhibited significantly higher DNA damage, total oxidant status and oxidative status index values than the other groups. Relative to all other groups, Group 1 had a higher Cox-2 value. Relative to Group 1, Group 2 showed significantly higher HSF-1 value. Groups 2, 3 and 4 were similar in terms of IL-1 Beta, IL-6 and TNF-alpha values, however, relative to group 1, these values were significantly lower. These findings suggest therapeutic effect of early period of Metformin treatment on NIHL.