Sensorineural Hearing Loss (SNHL) (click to expand)
Sensorineural hearing loss (SNHL) 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, SNHL cannot be medically or surgically corrected. This is the most common type of permanent hearing loss.
SNHL reduces the ability to hear faint sounds. Even when speech is loud enough to hear, it may still be unclear or sound muffled.
Possible Causes of Sensorineural Hearing Loss:
• Drugs that are toxic to hearing
• Hearing loss that runs in the family (genetic or hereditary)
• Head trauma
• Malformation of the inner ear
• Exposure to loud noise
Conductive Hearing Loss (click to expand)
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.
Possible Causes of Conductive Hearing Loss:
• Fluid in the middle ear from colds
• Ear infection (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
Mixed Hearing Loss (click to expand)
Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss (SNHL). In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.