There are three main classifications of hearing loss currently recognized: conductive, sensorineural, and mixed. In addition to the type of hearing loss, it is possible to only have deficiency in one ear (unilateral) or both ears (bilateral). Within each classification of loss, there are varying degrees of severity as well.
Let's take a look at each hearing loss type and break them down a bit further.
Conductive Hearing Loss
Conductive hearing loss occurs when the sound is not making its way to the inner ear (the cochlea). This can occur due to ear canal malformation, a dysfunction of the eardrum, or a malfunction of the bones in the middle ear. It is possible for the eardrum to show defects of various degrees, from slight to total, resulting in hearing loss of different degrees. It is also possible for scar tissue from ear infections to cause dysfunction of the medial part of the middle ear.
Dysfunction of the three small bones of the middle ear (malleus, incus, and stapes) may also cause conductive hearing loss. Lastly, mobility of the ossicles may impair for different reasons and cause disruption of the ossicular chain due to trauma, infection, or anchylosis which may also cause hearing loss.
Sensorineural Hearing Loss
Sensorineural hearing loss is caused by dysfunction of the inner ear (the cochlea), the nerve that transmits the impulses from the cochlea to the hearing center in the brain, or damage in the brain. The most common cause of this hearing loss type, however, is damage to the hair cells in the cochlea. It is widely regarded that 50% of adults over the age of 70 have this type of hearing loss.
Mixed Hearing Loss
Mixed hearing loss is a combination of the two types discussed above. Chronic ear infections can cause defective eardrum or middle ear ossicle damage or both.
If you suspect you may have hearing loss, it is important to identify the type of hearing loss and level of severity you may be experiencing. That way, you can select the best treatment option to address that loss.
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