Types of Hearing Loss
Conductive Hearing Loss (CHL)
CHL occurs when sound is unable to efficiently pass through the outer ear canal to the eardrum and the tiny bones of the middle ear. This type of hearing loss can often be corrected medically or surgically.
Some possible causes of CHL:
- Fluid in the middle ear from colds
- Ear infection (otitis media)
- Allergies (serous otitis media)
- Poor eustachian tube function
- Perforated eardrum
- Benign tumors
- Impacted earwax (cerumen)
- Infection in the ear canal (external otitis)
- Presence of a foreign body
- Absence or malformation of the outer ear, ear canal, or middle ear
This diagram shows the different degrees of hearing loss. Most speech is heard between 250Hz and 4000Hz.
Sensorineural Hearing Loss (SNHL)
SNHL occurs when there is damage to the inner ear or to the nerve pathways from the inner ear to the brain. This is the most common type of permanent hearing loss.
Some possible causes of SNHL:
- Illnesses
- Drugs that are toxic to hearing
- Hearing loss that runs in the family (genetic or hereditary)
- Aging (Presbycusis)
- Head trauma
- Malformation of the inner ear
- Exposure to loud noise
Mixed Hearing Loss
In some cases, a combination of CHL and SNHL may exist. When this occurs, the hearing loss is referred to as a mixed hearing loss.
Please contact Hearing Healthcare of East Gwillimbury if you think any of the above may apply to you.