More than 5% of the world's population suffers from disabling hearing loss. If the cause of hearing loss is unclear, it is referred to as idiopathic sudden sensorineural hearing loss (ISSNHL). After failure of standard treatment, the use of hearing aids or a cochlear implant is generally recommended. In this case, a 55-year-old patient was treated with cochlear implantation (CI) after ISSNHL and unsuccessful conservative therapy. Approximately 1 year after implantation and 7 years after the sudden hearing loss, subjective measurements revealed restoration of the hearing threshold.