Disease

What causes hearing loss?

In adults, the most common causes of hearing loss are:

Noise

Noise-induced hearing loss can affect people of all ages and most often develops gradually over many years. Over time, the noise experienced at work, during recreation (such as riding motorcycles), or even common chores (such as using a power lawn mower) can lead to hearing loss.

Age

In age-related hearing loss (presbycusis), changes in the nerves and cells of the inner ear  that occur as you get older cause a gradual but steady hearing loss. The loss may be mild or severe, but it is always permanent.

What types of hearing loss?

Hearing loss can be categorized by which part of the auditory system is damaged. There three basic types of hearing loss are conductive hearing loss, sensorineural hearing loss and mixed hearing loss.

•  Conductive hearing loss

Occurs when sound is not conducted efficiently though the outer ear canal to the eardrum and the tiny bones of the middle ear. Conductive hearing loss usually involves a reduction in sound level, but it is usually temporary because in most cases medical treatment can help.

• Sensorineural hearing loss

Occurs when there is a damage to the inner ear (cochlea) or to the nerve pathways. It cannot be medically or surgically corrected which means it is a permanent loss.

Sensorineural hearing loss not only involves a reduction in sound detection level, but also affects speech understanding.

Can be caused by diseases, birth injuries, drugs that are toxic to the auditory system, genetic syndromes, head trauma, aging, tumours as well as viruses.

•  Mixed hearing loss

A conductive hearing loss occurs in combination with a sensorineural hearing loss.

•  Unilateral hearing loss

Patients experience hearing loss in only one of the ears.

 Image courtesy of  en.wikipedia.org/wiki/File:FA-18_Hornet_breaking_sound_barrier_%287_July_1999%29_-_filtered.jpg This image is in the public domain and thus free of any copyright restrictions.