Types of Hearing Loss
Hearing loss affects about one out of every 10 Americans. For those over 65 years of age, the ratio is nearly one in three. There are different types and varying degrees of hearing loss. Some hearing losses can be treated medically while others may be permanent.
Hearing loss is classified according to which part of the auditory system is affected. Generally there are three types of hearing loss: conductive, sensorineural and mixed.
Conductive Hearing Loss
Conductive hearing loss is the result of disorders in either the outer or middle ear, which prevent sound from getting to the inner ear. Voices and sounds may sound faint, distorted or both.
Some common causes of conductive hearing loss:
- Infection of the ear canal or middle ear
- Fluid in the middle ear
- Perforation or scarring of the eardrum
- Wax build-up
- Dislocation of the ossicles (three middle-ear bones)
- Foreign objects in the ear canal
- Otosclerosis
- Unusual growths, tumors
Back to top
Sensorineural Hearing Loss
Sensorineural hearing loss occurs when inner ear nerves become damaged and do not properly transmit their signals to the brain. Patients may complain that people seem to mumble or that they hear, but do not understand, what is being said. The aging process is the most common cause of sensorineural hearing loss. As we get older, the inner ear nerves and sensory cells gradually die.
In addition to advancing age, sensorineural hearing loss can be caused by:
- Injury
- Excessive noise exposure
- Viral infections (such as measles or mumps)
- Ototoxic drugs (medications that damage hearing)
- Meningitis
- Diabetes
- Stroke
- High fever
- Ménière's disease
- Acoustic tumors
- Heredity
Back to top
Mixed Hearing Loss
If a hearing loss is the result of both conductive and sensorineural components, it is known as a mixed hearing loss.
Back to top
