Types of hearing loss
There are three types of hearing loss. Conductive, sensorineural or a mixed hearing loss (which is a combination of both).
Conductive hearing loss is caused by problems to the outer and middle ear (see diagrams A and B). With conductive hearing loss the sound waves cannot travel through to the inner ear effectively and so sounds will appear quieter. Conductive hearing loss can be caused by earwax, fluid in the middle ear, a damaged eardrum, damage to the middle ear bones (the ossicles), genetic defects or infection. Most problems related to the outer and middle ear can be addressed by medication or surgery. If this is not possible, hearing loss may be treated successfully in most cases with a hearing aid.
Sensorineural hearing loss occurs when the tiny sensory hair cells along the membrane of the fluid filled cochlea become damaged (see diagram C). Sensorineural hearing loss may occur due to gradual wear and tear of the sensory hair cells through the ageing process. Other causes are exposure to loud noise, illness, medications, genetics and head trauma. With sensorineural hearing loss, sounds may appear quieter but also distorted. In most cases this is where hearing systems are advantageous in treating hearing loss. Find out if you have a reduced hearing range.