Cochleovestibular disorders (hearing loss, vestibular disorders) are a frequent reason of healthcare consultation; however, the underlying pathophysiology often remains unclear. Murine research on cochleovestibular disorders is relevant as the inner ear structure and function of mice is largely comparable with humans. Both objective hearing and vestibular tests in mice have been well described, although a comprehensive vestibular test battery has been rarely performed in literature. In this project, we want to explore the pathophysiology and local treatment options of certain inner ear disorders. We have performed preliminary work about murine congenital cytomegalovirus infection (cCMV) and hearing loss, which enables us to test therapeutic options in a next step. The antiviral ganciclovir already showed promising results on cCMV hearing loss but its systemic application is limited due to side effects, so local intratympanic therapy with this and with corticosteroids will be researched. A second target is the cochleovestibular loss of ototoxic chemotherapy. Both cisplatin and carboplatin are known to be able to induce inner ear dysfunction. The pathophysiology of cisplatin has also been studied in mice, but a decent animal model for carboplatin, which works at other effector cells (hidden hearing loss) compared to cisplatin, is lacking. We are currently establishing a minimally invasive mouse model for carboplatin ototoxicity which is in line with the 3R model for valuable animal research (replace, reduce, refine), and again will enable us to test local therapeutics. If the hypotheses of this project can be accepted, changes in the treatment protocol of these disorders might be considered in future, improving the treatment of numerous patients with inner ear disorders.