well as supplementing hearing with lip-reading, cued speech or sign language. cochlear implants a cochlear implant is an electronic device that is surgically implants to stimulate the cochlear nerve. cochlear implants will work only when the cochleovestibular nerve (8th nerve) and the cochlea are still functioning. in a study done with open-set speech perception testing and closed-set speech perception testing by neff et al., they discovered that the use of cochlear implants with nf2 patients allowed significant improvement of hearing abilities. in testing of recognition of sentences of everyday speech, five out of six patients scored within the 90–100% range, and in testing of hearing in noise setting, four of six of the patients scored within the 83–96%. additionally, all testing was done without lip-reading. auditory brainstem implants (abis) auditory brainstem implants, or abis, are used when the cochlea or any portion of the cochleovestibular nerve are not functioning due to damage to those areas or anatomic abnormalities. the procedure is done by implanting a device that send an electrical signal directly to the cochlear nucleus, allowing sound to bypass the peripheral auditory system and straight into the brain stem. prognosis nf2 is a life limiting condition. it is a rare genetic disorder that involves noncancerous tumors of the nerves that transmit balance and sound impulses from the inner ear to the brain. the prognosis is affected by early age onset, a higher number of meningiomas and schwannomas and having a decrease in mutation. an early diagnosis is the best way to ensure improvement in management. although, even with an early diagnosis, some patients still die very young. meningiomas and schwannomas occur in around half of patients with nf2. meningiomas are tumors that are both intracranial and intraspinal. schwannomas are tumors that are often centered on the internal auditory canal. patients with nf2 who have meningiomas have a higher risk of mortality, and the treatment can be very challenging. individuals who develop schwannomas frequently develop hearing loss and deafness. these individuals may also develop tinnitus after being presented with unilateral hearing loss. the first symptom that individuals may encounter is dizziness or imbalance. truncating mutations lead to smaller and non-functional protein products. studies have shown that missense mutations and large deletions can both cause predominantly mild phenotypes. phenotype is more variable in patients with splice-site mutations, and a milder disease in patients with mutations in exons 9–15. patients with a missense mutation have a greater survival rate than nonsense and frameshift mutations. prevalence incidence of the condition is about 1 in 60,000.