Inclusion Criteria:  Vestibular schwannoma's Patients for whom an indication of gammaknife radiosurgery was determined in a dedicated multidisciplinary consultation meeting, having not received previous treatment for this schwannoma. Patient affiliated to Social Security No opposition to participation  Exclusion Criteria:  History of prior treatment for the presented vestibular schwannoma (surgery, fractional radiotherapy) History of otological or otoneurological pathology associated with schwannoma Patient with type 2 neurofibromatosis Patient under legal protection Pregnant or breastfeeding women