Sensorineural hearing loss (SNHL) is a type of hearing loss, or deafness, in which the root cause lies in the inner ear (cochlea and associated structures), vestibulocochlear nerve (cranial nerve VIII), or central auditory processing centers of the brain. SNHL accounts for about 90% of hearing loss reported. A hallmark of such hearing loss is that it is asymmetrically distributed usually toward the high frequency region, or may have a notch at some frequency. SNHL is generally permanent and can be mild, moderate, severe, profound, or total.