Hearing loss is a major public health issue. It is the third most common physical problem after arthritis and heart disease. Hearing loss is an invisible condition. We cannot see hearing loss, only its effects. Because the presence of a hearing loss is not visible, these effects may be attributed to aloofness, confusion or personality changes. Varying from mild to profound, hearing loss can be a sudden or gradual decrease in how well you can hear. Depending on the cause, it can be temporary or permanent.
There are three basic types of hearing loss. They are:
Conductive hearing loss
Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the tiny bones (ossicles) of the middle ear. Conductive hearing loss usually involves a reduction in sound level or the ability to hear faint sounds. This type of hearing loss can often be corrected medically or surgically.
Some possible causes of conductive hearing loss:
- Fluid in the middle ear
- Ear infection (otitis media)
- Impacted earwax (cerumen)
- Infection in the ear canal (external otitis or swimmer’s ear)
- Presence of a foreign body
Sensorineural hearing loss (SNHL)
Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the brain. Most of the time, sensorineural hearing loss cannot be medically or surgically corrected. This is the most common type of permanent hearing loss.
Some possible causes of SNHL:
- Hearing loss that runs in the family (genetic or hereditary)
- Aging
- Head trauma
- Exposure to loud noise without the use of hearing protection
Mixed hearing loss
Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.
