Evaluating How a Tinnitus Implant Affects Tinnitus Loudness in Adults With Chronic Tinnitus and Varying Levels of Hearing Loss

Inclusion criteria

• 18 years or older.

• Normal hearing to moderately severe sensorineural hearing loss defined as a puretone average (PTA) at 500, 1000, 2000 and 4000 Hz less than 65 dB HL in both ears (separately) and best-aided phoneme recognition score more than or equal to 80% inboth ears (separately).

• Unilateral or asymmetric subjective (no pulsatile) tinnitus. In case of asymmetrictinnitus, the worst ear must be implanted.

• Tinnitus duration of at least 6 months.

• Severe tinnitus loudness determined by a. VAS-L score in the severe range i.e. 50-100/100 b. TFI score in the severe range i.e. 52-90/100

• Tinnitus that is intractable and has not been ameliorated satisfactorily by standardof care such as CBT or hearing aid, when such interventions are potentiallyclinically indicated.

• Clinically significant reduction in VAS-L score (≥ 15/100 points) in response totrans-tympanic promontory stimulation

• Willing and able to provide written informed consent.

• Medically able to use the device and to undergo general anaesthesia for implantationtaking into account their medical condition, contraindications and surgical risks.

• Dutch language proficiency

Exclusion Criteria:

• Pulsatile tinnitus.

• Any anatomical or structural abnormalities of the inner ear, cochlear nerve, orbrainstem that would negatively impact response to study intervention (determined ina temporal bone CT and if necessary (e.g. possibility of vestibular/acousticschwannoma) by a MRI scan of the head (of sufficient quality at the discretion ofthe investigator) not more than five years old at the time of enrolment

• Medical contraindications limiting correct placement, activation, or treatment (determined by medical history; contraindications include brain or major earsurgery, brain or temporal bone tumor(s), recurrent ear infections within the lastyear, otosclerosis, prior major head trauma that results in sudden injury thatcauses damage to the brain and results in lasting cognitive impairment).

• Any medical condition, including mental illness or substance abuse, deemed by theInvestigator to likely interfere with a patient's ability to sign informed consent,cooperate and/or participate in the study, or interfere with the interpretation ofthe results (incl. pregnant or breastfeeding women or patients with unrealisticexpectations).

• Presence of clinically diagnosed depression or anxiety determined by a psychologicalstate evaluation (if PHQ-9 > 9 or GAD-7 > 9).

• Active (currently or within two months prior to enrolment) use of medications (taking regularly scheduled antidepressant, anxiolytic, antipsychotic orantiepileptic medications, or other neuromodulator agents) or other tinnitustreatments.

• It is permissible to include people who use such medications at lower doses as asleep aid or for people who intermittently use such medications for situationalanxiety (e.g., Ativan before airplane travel). A change in medication during thetrial should be avoided.

• It is permissible to include people who prefer to use a hearing aid to amplifyipsilateral hearing loss. The start of using a hearing aid during the trial shouldbe avoided.

• Investigator site personnel directly affiliated with this study and/or theirimmediate families; immediate family is defined as a spouse, parent, child, orsibling.

• Cochlear employees or employees of Contract Research Organizations or contractorsengaged by Cochlear for the purposes of this investigation.

• Current participation, or participation in another interventional clinicalstudy/trial in the past 60 days, involving an investigational drug or device (unlessthe other investigation was/is a Cochlear sponsored investigation and determined bythe investigator or Sponsor to not impact this investigation).