**6. Caffeine and auditory system**

A larger number of studies have been found attempting to investigate the effects of caffeine in the auditory system. It is believed that caffeine affected the peripheral and central auditory pathways [45]. As the inner ear is the site of lesion for this clinical syndrome, we direct our efforts in presenting the effects of caffeine on the peripheral auditory system [46].

Regard to the effects of caffeine on the peripheral auditory system, it was demonstrated that caffeine induced shortening of outer hair cells, increasing the excitability of the peripheral auditory pathways [47]. The mechanism of action that provides this shortening has not been fully elucidated [13]. It was suggested that caffeine induced contraction by activating the ryanodine receptor, by potassium channel blockage or by creating osmotic imbalance across the cell membrane [47–49].

No clinical studies in humans to investigate the relationship of caffeine to the peripheral auditory system were found.
