Conductive Hearing Loss
Conductive hearing loss is a problem in the outer or middle ear that prevents sound from reaching the inner ear. Many times, conductive hearing losses are temporary and can be treated with medical intervention.
Some possible causes of conductive hearing loss are:
- Fluid in the middle ear from colds
- Ear infections
- Perforated eardrum
- Impacted cerumen (earwax)
- Benign tumors
- Swimmer’s ear
- Presence of a foreign body
- Absence or malformation of the outer ear, ear canal, or middle ear
Sensorineural Hearing Loss
Sensorineural hearing loss is the result of a problem in the inner ear and occurs when nerve fibers in the cochlea are missing or damaged. The nerve fibers are known as the outer and inner hair cells, and they are responsible for transmitting signals to the brain which allows one to hear and interpret sound.
Some possible causes of sensorineural hearing loss are:
- Ototoxic drugs such as penicillin-based drugs or some chemotherapy drugs
- Head trauma
- Malformation of the inner ear
- Exposure to loud noise
Mixed Hearing Loss
Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. When there is damage to the outer or middle ear and the inner ear or auditory nerve, a mixed hearing loss is diagnosed.
Degree of Hearing Loss
It is very common to explain the degree of hearing loss by describing it as mild, moderate, severe and profound with some professionals also adding the term moderately-severe. It is less common to provide a percentage describing the degree of hearing loss unless the professional who provides that information can explain how the percentage was determined. A percentage based on the Articulation Index (AI) is based on research and calculates how much phonemic information (speech sounds) can be heard by the patient with more commonly used speech sounds such as the “s” given more weight compared to a relatively uncommon speech sound such as the “th” in feather.
Hearing loss is commonly described as the inability to hear softer sounds but based on the degree of hearing loss, the ability to interpret frequencies accurately and hear loudness correctly is also impacted.