Conductive hearing loss can be caused by infection, a perforated eardrum, or any number of diseases and conditions that block the ear canal and prevent sound from travelling from the outer or middle ear into the inner ear. It may alternatively be caused by a condition that prevents the middle ear from conducting sound vibrations through the stapes to the inner ear.
The result of conductive hearing loss is a loss of loudness and a reduction in intensity of sound. The degree of hearing loss varies, but can usually be overcome by simply increasing the loudness of sounds – i.e. by speaking loudly.
Sensorineural hearing loss can be the result of ageing, head trauma, excessive noise exposure, malformation of the inner ear, diseases and hereditary hearing loss. It commonly occurs as a person ages and is experienced as a loss of loudness and a lack of clarity in sound, often described as distortion.
As the name suggests, a mixed hearing loss is a combination of sensorineural hearing loss and conductive hearing loss. It is caused by problems in both the conductive pathway and the nerve pathway (the outer, middle and inner ear). As well as suffering permanent hearing loss in the inner ear, the person suffers from a conductive problem or blockage that prevents sound from travelling into the inner ear, making the degree of hearing loss worse.