What causes Hearing Loss?

Hearing issues may arise in all three parts of the ear. The most common types of hearing loss are conductive (outer and middle ear) and sensorineural (inner ear). If you suspect you have a hearing loss that has not been treated, you should visit a member of the New Zealand Audiological Society for a hearing test and expert advice.


Common conductive hearing loss causes

While the presence of ear wax is healthy and normal, a build-up can occur over time causing hearing loss and a blocked sensation. An ear wax blockage is best treated by an Ear Specialist, Ear Nurse Specialist or trained NZAS Audiologist or Audiometrist.

A common hearing issue in the middle ear is Otitis media, better known as “glue ear.” A build-up of fluid in the middle ear prevents movement of the ear drum and hearing bones. Although this condition usually resolves itself within ten weeks without treatment, advice and help can be sought from your GP.

A less common issue in the middle ear is Otosclerosis. This condition arises from the abnormal growth of the hearing bones in the middle ear. Usually the stapes becomes fixed to the oval window of the cochlea and interferes with sound transmission into the inner ear. Otosclerosis is sometimes treated by surgery or through the use of hearing aids.


Common sensorineural hearing loss causes

Sensorineural hearing loss, unlike conductive hearing is usually permanent and caused by damage or malformation of the sensory hearing “hair cells” in the inner ear.

Outer hair cells deteriorate over time so that only about 70% are intact by 70 years of age. This can result in reduced hearing of high pitch sounds and loss of hearing clarity. Hearing aids are usually very beneficial in compensating for this type of hearing loss.

Exposure to excessive noise can accelerate damage to outer hair cells causing a greater magnitude of hearing loss. Appropriate hearing protection should be used when in the presence of excessively loud sound to reduce damage to sensory hearing cells. Hearing aids are usually very beneficial in compensating for this type of hearing loss.

Damage to inner hair cells can occur due to excessive noise, ear disease or degenerative conditions.

Hearing aids are most effective at compensating for reduced function of outer hair cells, which is the most common type of permanent hearing loss. If the function of inner hair cells is very poor then a cochlear implant may provide better hearing ability. Your NZAS Audiologist or Audiometrist can explain the type of hearing loss and recommend the best course of action to improve your hearing.