The term ‘cookie-bite hearing loss’ doesn’t have anything to do with baked goods, unfortunately. What it refers to is the shape created on an audiogram – a visual graph that shows the results of a hearing test – when a person has trouble hearing tones in the mid-range.
“It got that name because when a patient with this pattern of hearing loss has an audiogram and the hearing thresholds are graphed, the pattern is a ‘U’ that looks as if someone took a bite out of it,” explained Dr. Jordan Glicksman, M.D., MPH, FACS, FRCSC, who is an otolaryngologist, rhinologist and skull base surgeon, as well as a part-time lecturer at Harvard Medical School.
Cookie-Bite Hearing Loss Is Sensorineural
There are two types of hearing loss: conductive and sensorineural. Conductive hearing loss is caused by a physical blockage in the ear that prevents soundwaves from passing through
. Sensorineural hearing loss is caused by damage to the inner ear. Cookie-bite hearing loss is the latter.
Within the cochlea are tiny hair cells called cilia. These cells convert soundwaves into electrical energy that travels via the auditory nerve to the brain to be interpreted as sound. When there is damage to the cilia or the auditory nerve, the result is sensorineural hearing loss: a permanent condition.
What Sounds Are Affected?
As stated previously, cookie-bite hearing loss is related to loss of mid-tones. Much of human speech and music falls in the mid-range, between about 500 Hz and 2,00 Hz.
High-frequency hearing loss, indicated with a downward sloping audiogram, is more common and causes difficulty with sounds like birds chirping and the voices of children.
Low-frequency hearing loss is indicated with an upward sloping audiogram and affects the ability to hear sounds like thunder and some men’s voices.
What Causes Cookie-Bite Hearing Loss?
Cookie-bite hearing loss is usually a genetic condition. Family history of mid-range hearing loss is a factor. Cookie-bite hearing loss can present at birth or develop over time.
In more rare circumstances, this type of hearing loss can be the result of an acoustic neuroma (a benign tumor on the auditory nerve).
For more information about cookie-bite hearing loss or to schedule an appointment for a hearing test, call the experts at the Hearing & Balance Center of Charleston ENT today!