The Three Main Classifications of Hearing Loss

There are three main classifications of hearing loss currently recognized. Conductive hearing loss, Sensorineural hearing loss, and Mixed hearing loss. 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.

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 that the eardrum might show defects of various degrees from slight to total resulting in hearing loss of different degrees. It is also possible for scar tissue that has occurred 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 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 single most common reason for this type of hearing loss is damage to the hair cells in the cochlea. It is recognized that 50% of adults over the age of 70 have this type of 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.

It is important to understand the different kinds of hearing loss, the level of severity of the loss, and the best tools to help compensate for your specific loss. If you still have questions regarding hearing loss, please contact our helpful staff and we will walk you through the process and help you determine what is right for your needs.