Types of Hearing Loss
Hearing loss is identified by the part of the auditory system that is damaged. There are three basic types of hearing loss: conductive hearing loss, sensorineural hearing loss and mixed hearing loss.
Conductive Hearing Loss
Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the eardrum and the ossicles of the middle ear. This type of hearing loss usually involves a reduction in sound level or the ability to hear faint sounds.
Some possible causes of conductive hearing loss include:
- Absence or malformation of the outer ear, ear canal, or middle ear
- Benign tumors
- Ear infection
- Fluid in the middle ear
- Impacted earwax
- Perforated eardrum
- Poor eustachian tube function
- Swimmer’s Ear
- Sensorineural Hearing Loss
Sensorineural hearing loss occurs when there is damage to the inner ear or to the nerve pathways from the inner ear to the brain. This type of hearing loss reduces the ability to hear faint sounds. Even when speech is loud enough to hear, it may still be unclear or sound muffled.This is the most common type of permanent hearing loss.
Some possible causes of sensorineural hearing loss include:
- Drugs that are toxic to hearing
- Exposure to loud noise
- Head trauma
- Hearing loss that runs in the family (genetic or hereditary)
- Malformation of the inner ear
Mixed Hearing Loss
Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. There may be damage in the outer or middle ear and in the inner ear or auditory nerve.