4 facts about hearing loss:
- It is one of the most common congenital disorders (abnormalities present at birth that develop in the womb and are caused by genetics, toxins or unknown reasons) in humans.
- Out of every 1,000 babies in the U.S., two to three are born deaf or hard-of-hearing.
- Hearing loss is one of the leading disabilities among older people.
- In the U.S., hearing impairment affects 18 percent of adults age 45 to 64, 30 percent of adults age 65 to 74, and 47 percent of adults age 75 or older have a hearing impairment according to the
National Institute on Deafness and Other Communication Disorders (NIDCD).
How Hearing Works
The sense of hearing is achieved through a combination of functions of the outer ear, middle ear and inner ear. Sound waves pass through the outer ear, are conducted through the middle ear, and travel to the inner ear.
The inner ear is a fluid-filled series of chambers. One of these chambers, the cochlea, is responsible for converting sound vibrations into nerve impulses. It is these nerve impulses that the human brain interprets as sound and what we call “hearing.”
The inner ear also contains the semicircular canals which are responsible, in part, for sensing movement and maintaining balance.
Disorders of any of these structures can lead to hearing loss.
Learn about how we test for hearing loss.
Types of Hearing Loss
Hearing loss can be conductive, sensorineural or both.
Conductive hearing loss: This occurs when there is a mechanical problem in the outer or middle ear and sound does not reach the inner ear (cochlea). Causes of conductive hearing loss include:
Sensorineural hearing loss: This type of hearing loss is caused by damage to the sensory hair cells of the inner ear (cochlea), or to the auditory nerve. The hair cells convert sound vibrations from the middle ear into electrical pulses, which are then sent along the auditory nerve to your brain.
Ear infections (otitis media, external otitis and others)
- Fluid in the middle ear
- Cerumen (ear wax) impaction
- Benign tumors such as
- Perforation of the tympanic membrane
- Malformation of the outer ear, ear canal or middle ear bones
Repeated exposure to loud sounds, damaging chemicals and ototoxic drugs (medications that can damage hearing including aspirin, certain antibiotics/chemotherapies) can cause damage to the sensory haircells in the cochlea. Presbycusis, which is age-related hearing loss, is sensorineural and the result of degeneration of the sensory hair cells. Other causes of sensorineural hearing loss are idiopathic,autoimmune disease or tumors.
Treatment depends on the cause and type of hearing loss.
Some hearing disorders can be treated medically or surgically.
cochlear implants and assistive hearing devices can also help if hearing is not treatable or restored to an acceptable level.
Assistive hearing devices are used in different settings depending on a person’s particular needs. Examples of assistive hearing devices include:
- Amplified telephones and answering machines
- Wake-up alarms that vibrate
- Loud door bells
Read more about these devices through
Surgery can be an effective treatment solution for hearing loss caused by:
- Perforation of the eardrum
- Congenital malformations
We provide advanced microsurgery, minimally invasive surgery, and complex open surgeries to patients from throughout the region to address these conditions.
Comprehensive Cochlear Implant Program
A cochlear implant is an electronic device that bypasses damaged areas in the ear and stimulates the auditory nerve fibers in the cochlea, providing hearing to people with moderate to profound sensorineural hearing loss. This is very different from hearing aids.
Cochlear implants require a period of adaption for your brain to relearn sounds using an electrical signal. However, the benefits include being able to distinguish environmental sounds, have conversation (in person and on the phone).
UC San Diego Health operates the largest cochlear implant program in the region. Our expertise in this area spans over 25 years of continuous expert care. Our team includes five cochlear implant surgeons and four cochlear implant audiologists.