Middle ear hearing loss

May 30, 2014 by Charles Halluin

What is the middle ear? The middle ear is an air-filled cavity located between the eardrum and the stapes footplate. It comprises the ossicular chain—the malleus (hammer), the incus (anvil), and the smallest bone in the human body, the stapes (stirrup)—and two muscles, the tensor tympani and the stapedius.

How it works is quite simple: like a drum, the eardrum pushes air toward the ossicular chain. The chain acts as a lever to mechanically enhance the transmission of sound to the fluids of the inner ear. If any part of this transmission chain is broken or damaged, it will result in hearing loss.

Conductive hearing loss
A gap is observed between the bone conduction curve and the air conduction curve.
Middle ear

Conductive hearing loss

The primary causes of hearing loss associated with the middle ear include a perforated eardrum, otitis, ossicular chain dysfunction and Eustachian tube dysfunction.

Some cases, otitis for instance, can be treated with medication. In other cases, surgical procedures, such as a stapedectomy (replacing the stapes), may be a solution. Wearing hearing aids can also be an effective solution for hearing loss in the middle ear.

Most of the time, this type of hearing loss (conductive) is easily treated with hearing aids since it is typically associated with a gain (volume) problem rather than a problem with understanding (distortion and clarity). As such, hearing aids provide very effective audio reproduction and quickly produce noticeable results.

The sound of a breeze blowing through the trees or crickets chirping on a warm summer night… a hearing aid fitting can enable users to perceive noises they may not have heard in years.

Keep in mind, however, that you should always consult an ENT specialist to determine the best course of action for treating hearing loss. If you have any questions about a hearing aid fitting, consult an audioprosthetist at one of the Lobe Santé auditive et communication multidisciplinary clinics.

References:

-BESS, H., and L.E. HUMES. Audiology: The
Fundamentals, Lippincott Williams & Wilkins, 1995-01-01, 334 pages.

-HAWKE, M., and A. McCOMBE. Diseases of the Ear: A Pocket Atlas, Manticore Communications, 1995, 106 pages.