Implantation of an Auditory Brainstem Implant for the Treatment of Incapacitating Unilateral Tinnitus

Inclusion Criteria: * Unilateral tinnitus * Severely invalidating tinnitus * Men or women, age \>18yr * Tinnitus that is present \>1 years and was stable during the last year * Tinnitus that is nonresponsive to indicated conventional existing treatments (hearing aids and cognitive behavioral therapy (CBT)). If a psychologist has indicated that CBT may ameliorate tinnitus complaints, the patient should have tried CBT for long enough time to reasonably argue that these treatments were not successful. This is the same for hearing aids. * Ipsilateral ear: pure tone audiometry (PTA) thresholds \>40dB and \<90dB (mean over 1-2-4kHz) * Functional hearing in the contralateral ear with pure tone audiometry thresholds \<35dB (mean over 1-2-4 kHz) and with a minimum Δ25dB compared to the ipsilateral ear. * Informed consent after extensive oral and written information about the surgery, complications and the uncertain effect of the ABI on tinnitus Exclusion Criteria: * Detectable cause for tinnitus that requires causal therapy (e.g. vestibular schwannoma, glomus tumor, otosclerosis, arteriovenous malformation) as investigated by radiological and otological examination * Psychiatric pathology and/or an unstable psychological situation as declared by a psychiatrist * Unrealistic expectations as declared by the investigator and/or psychiatrist * Life expectancy \<5 years * History of blood coagulation pathology * ASA \>II * Pregnancy * Anatomic abnormalities that would prevent appropriate placement of the stimulator housing in the bone of the skull * Anatomical abnormalities or surgical complications that might prevent placement of the Auditory Brainstem Implant Active Electrode Array * Known intolerance to the materials used in the implant (medical grade silicone, platinum, iridium and parylene C)