Audiology is a science division that studies hearing, equilibrium, and related disorders. Audiologists treat people with hearing loss and proactively prevent related damage. Through using various research methods, audiologists seek to assess whether someone has natural sensitivity to the sounds. Once hearing loss is detected, audiologists assess which portion of the hearing (high, medium, or low frequencies) are impaired, to what degree (damage severity), and where the hearing loss impairment (outer, middle, inner, auditory, and/or central nervous system) is located. When a hearing impairment or vestibular abnormality is assessed by an audiologist, he or she may provide instructions for treatment or rehabilitation such as hearing aids or cochlear implants.