Inclusion Criteria:  Criterion for inclusion of a patient is the requirement of the translabyrinthine approach for tumor removal. The surgical approach is determined by the tumor size, the tumor location and the remaining hearing of the patient. Criteria for a translabyrinthine approach are:  the tumor grows in the pontine angle and the facial nerve is at risk for damage during the surgery because the tumor is already large and in close proximity of the facial nerve AND the tumor is larger than 2.5 cm AND Pure tone hearing thresholds are elevated by at least 50 dB AND Speech discrimination scores are 50% or less  Exclusion Criteria:  adults unable to consent. individuals who are not yet adults (infants, children, teenagers). pregnant women. prisoners. vulnerable populations