Human Ear and Hearing Loss
Before discussing the many forms of hearing loss, a basic understanding of the parts of the ear and how the ear works is necessary.
The ear is divided into three parts (see figure below): (1) The outer ear which includes the part that you can see and the ear canal. The outer ear directs the vibrations of sound to the middle ear: (2) The middle ear which includes the ear drum (tympanic membrane), the three small bones (called ossicles), and the small air space which surrounds the ear bones. The middle ear is where vibrations of sound are amplified. The space is kept filled with air by the normal function of the eustachian tube which connects the middle ear to the upper throat: (3) The inner ear, which includes the cochlea, is where the nerve signals for hearing are made. The semicircular canals, also a part of the inner ear, are for balance, and the nerves take the signals to the brain. The inner ear is where the vibrations are turned into electric signals.
It is important to understand the parts of the ear because hearing loss is classified by which part of the ear is not working. Hearing loss is diagnosed with a physical examination and a hearing test (audiogram). Sometimes other testing is recommended: MRI (brain scan), electrical hearing test (ABR), blood tests.
Conductive Hearing Loss
Conductive hearing loss refers to problems related to the areas of the ear involved with the vibrations of sound, i.e. the outer ear and the middle ear.
Common Problems Which Can Affect the Outer Ear and Cause Conductive Hearing Loss
Swimmer’s Ear: (otitis externa) Hearing loss caused by swelling in the canal requires medical treatment
Ear Wax: If too much wax completely blocks the canal. A little wax is necessary to moisturize the skin and kill bacteria. NEVER try to remove ear wax with a Q-tip or bobby pin. Over-the-counter ear cleaning kits are ok. DO NOT use the candle wax method. Sometimes an ENT doctor needs to remove the wax with suction or irrigation.
Foreign Bodies: Especially in children but also in adults. Let the doctor remove it!
Tumors: A rare cause of hearing loss. Surgery required.
Common Problems with the Middle Ear
Perforated Ear Drum: (hole) Can be from infection or injury. Often heals by itself, but must be evaluated by an ENT doctor. Can lead to infection if not treated.Sometimes requires surgery (“Tympanoplasty”) to fix.
Fluid or Infection in the Middle Ear: (otitis media) If the eustachian tube does not function properly, fluid may collect in the middle ear. This is especially common in young children because their eustachian tubes have not matured. Fluid impairs the normal vibration of the ear bones, causing hearing loss. Uninfected fluid may go away by itself with the aid of decongestants and “popping” of the ears. If the fluid persists, draining the fluid (Myringotomy) may be recommended. This can be done in the office in adults. Sometimes a tube is placed to prevent recollection of the fluid (especially in children). Infection of the middle ear requires antibiotics. After the infection is gone, fluid may persist for a period of time. Hearing loss will continue until the fluid is gone. Placement of tubes may be recommended for recurrent infections. Chronic infection may require surgery.
Ear Bone (Ossicle) Problems: The ear bones can become damaged by repeated infection or injury. If they are damaged or not all connected properly, hearing loss will result. The third and smallest ear bone, the stapes, sometimes gets locked in to position by bony overgrowth. This is called otosclerosis. Ear bone problems are often associated with a hole in the ear drum. The hearing loss from ear bone problems is remedied by a hearing aid or surgery.
Cholesteatoma: Cholesteatoma is a skin cyst in the middle ear. It is usually associated with a hole in the ear drum and ear bone damage. It can by very destructive and sometimes cause permanent hearing loss. The only effective treatment is surgery (“Tympanoplasty/Mastoidectomy”). Sometimes multiple operations are required.
Tumor: Rare causes of hearing loss. Surgery usually required.
To schedule an appointment with an Ear, Nose and Throat (ENT) doctor from ExcelENT of Alabama, email us, or call (205) 259-5555.