Noise induced hearing loss: the role of oxidative stress

Introduction: Noise-induced hearing loss (NIHL) is a relevant source of hearing disability affecting the general population, and accounts for about 16% of all the reported cases of disabling hearing loss in the adult population worldwide. NIHL can follow workplace-related and recreational noise exposure, and can be influenced by individual factors such as age, sex, genetic predisposition and socio-economic factors. Objectives: The aim of this paper is to provide a quick overview of the principal ndings in noise induced hearing loss, focusing on the role of oxidative stress and antioxidant intervention. Review: Oxidative stress plays a central role in leading to a condition of NIHL. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) largely participate in cellular mechanisms that underlie mainly the outer hair cell death after noise exposure and lead to sensorineural hearing loss. The beneficial effects of antioxidant supplementation have been demonstrated by several experimental studies in animals, while the observed results in humans are mixed. Conclusion: NIHL still represents a widespread condition among the general population; with a higher prevalence in developing countries among workers, and in developed countries among young adults exposed to leisure noise. Extensive literature confirms that increasing antioxidant levels in the organ of Corti may be an appropriate approach towards understanding NIHL in humans by increasing the endogenous antioxidant response or by administering antioxidant molecules systemically or locally.