Sensorineural Hearing Loss
What is sensorineural hearing loss?
Sound normally travels down the ear canal to vibrate the ear drum (tympanic membrane). The ear drum is connected to three middle ear bones (malleus, incus, and stapes), which transmit the sound into the inner ear (cochlea). The cochlea is the organ that changes sound vibrations into a nerve signal that goes to the brain.
Sensorineural hearing loss occurs when there is dysfunction of the cochlea or the nerve pathways of hearing.
What causes sensorineural hearing loss?
Many things can cause this type of hearing loss, either on one side, or both.
- Aging (presbycusis)
- Loud noise exposure
- Infections (ex. meningitis, measles, mumps, congenital cytomegalovirus, congenital toxoplasmosis, syphilis, herpes zoster oticus)
- Ototoxic medications
- Autoimmune disease
- Head trauma
- Meniere's disease
- Otosclerosis can cause both conductive and sensorineural types of hearing loss
- Inner ear birth malformations
- Vestibular schwannoma/acoustic neuroma
How is it evaluated?
Patients with hearing loss are first evaluated with a hearing test and an office exam. Tympanometry, which is a measure of the pressure on the inside of the eardrum, is often also performed at the same time as the hearing test. Depending on the pattern of hearing loss, some patients do not require additional testing. Other patients may undergo an MRI (for example, for one-sided sensorineural hearing loss), or laboratory testing.
How is it treated?
Management of sensorineural hearing loss depends on the cause. For example, in sudden one-sided sensorineural hearing loss, often steroid pills or steroid injections are used. In other cases, the underlying cause is addressed (for example, Meniere's, autoimmune disease, infection, tumors). Other causes are not reversible with today's medical technology, but our researchers are looking for a cure for the future.
Many patients can be helped with hearing aids. Cochlear implants may be an option for patients with severe to profound levels of loss.