Tinnitus induction in animals and its impact on auditory system structure

Tinnitus is a perception of sound in ears or head in the absence of any external stimuli. Despite its high prevalence in various age groups, tinnitus has still no effective treatment because its physiological and pathological mechanisms have remained unknown. Since the study of cellular-molecular mechanisms of tinnitus production and stability in human is not feasible, animal models have been used to shed some light on tinnitus induction and propagation mechanisms. This study reviewed some of these research studies. The present review article is based on articles published during 1967-2018 in which keywords such as “salicylate,” “noise,” “tinnitus in the animal model,” and “tinnitus mechanism” were used. These articles were searched in databases such as Science Direct, Google Scholar, PubMed, and Scopus. Despite differences in the mechanisms of tinnitus induction, the structural changes initiated from the cochlea and continued to cortex reflect the extent of the affected regions in the creation, development, and preservation of tinnitus. Animal models (exposed to noise or ototoxic drugs such as salicylate) are ideal tools for studying tinnitus and understanding the details of its propagation and unknown mecha nisms.