This is a proof-of-concept study designed to provide feasibility information on the clinical use of vagus nerve stimulation (VNS) paired with tones for the treatment of severe tinnitus. The study is expected to give preliminary efficacy and safety information.

Key Inclusion Criteria:

• 18 to 65 years of age
• Diagnosed with subjective tinnitus due to hearing loss with at least some tonal quality of the tinnitus.
• Diagnosis of tinnitus for at least one year
• Tinnitus severity of 18 or greater on TRQ cross checked with TQ severity of Grade 3 or worse

Key Exclusion Criteria:

• Acute or intermittent tinnitus
• Severe hearing loss
• History of significant ear disease such as Meniere's disease, ear tumors, or evidence of active middle ear disease.
• Any other implanted device