OBJECTIVE: To evaluate audiometric and vestibular signs and symptoms in a new DFNA9 family. SETTING: Tertiary referral centers. METHODS: A multigeneration Belgian family with late-onset progressive sensorineural hearing loss and concomitant ves-tibular impairment with an autosomal dominant pattern of inheritance underwent clinical and genetic evaluation. Medical history was recorded. Blood samples were taken for genetic linkage and mutation analyses. Pure-tone audiometry, speech audiometry and vestibular examinations were performed. Onset and progression in hearing impairment were evaluated with linear regression analysis of longitudinal threshold-on-age data. RESULTS: Linkage to DFNA9 was confirmed and mutation analysis revealed a P51S mutation in the COCH gene. Several patients had a Ménière's-like presentation. All patients developed late-onset progressive sensorineural hearing loss eventually leading to severe deafness and vestibular failure.