Types of Hearing loss
Hearing loss can be classified into three types: conductive, sensorineural, or mixed. The type of hearing loss a person has depends on where the problem is located within the auditory pathway.
First, let’s take a look at the anatomical structures that make up the auditory pathway in the picture. The ear itself (which is also called the pinna), ear canal, and eardrum make up the portion of the pathway called the outer ear. The middle ear is composed of three tiny bones: the incus, malleus and stapes (also called the anvil, hammer, and stirrup). The inner ear is made up of the cochlea (the snail shaped structure) and the nerves that go up to the brain. Hearing loss is classified as conductive if the problem is somewhere in the outer or middle ear pathway. If the problem is in the inner ear, the hearing loss is classified as sensorineural. In some cases problems may exist in both the outer and inner ear pathways. This is called mixed hearing loss.
Some common causes of conductive hearing loss include outer ear infection, middle ear infection and perforation (hole) in the ear drum. Sensorineural hearing loss can be the result of inner ear infection, noise induced damage to the cochlea or loss due to aging (presbycusis). Some medical conditions and medications can also cause sensorineural hearing loss. The most common and easily treated form of conductive hearing loss is a large buildup of waxy secretion in the ear canal.