After your hearing test, your results are printed on a chart known as an audiogram. Your hearing thresholds will be indicated by points on a graph and connected by a line. For most people with hearing loss, the line is flat or trends downward in the higher frequencies. For people with cookie-bite hearing loss, however, there’s a U-shaped dip in the middle, almost as if someone took a bite out of it.
What Is Cookie-Bite Hearing Loss?
Cookie-bite hearing loss, also called mid-frequency sensorineural hearing loss, is exceedingly rare, with a prevalence of only 0.7%. People with this condition struggle to hear sounds in the mid-range of frequencies, and can hear high- and low-frequency sounds much more easily. It’s like listening to music but only being able to hear the high instruments and the low instruments.
Critically, the mid-range of frequencies is where most of human speech resides. This means that people with cookie-bite hearing loss find listening to speech incredibly challenging. Conversations with friends, listening to dialogue-heavy scenes on TV and listening attentively in settings like lectures and meetings are all difficult with cookie-bite hearing loss.
What Causes Cookie-Bite Hearing Loss?
Cookie-bite hearing loss is almost always caused by genetics. Specifically, it’s most commonly caused by a mutation in the TECTA gene, which provides instructions for the development of the tectorial membrane, a membrane in the cochlea that helps convert sound waves into nerve impulses to be interpreted by the brain. Faulty TECTA instructions can cause dysfunction of the tectorial membrane, inhibiting the cochlea’s ability to transmit sound information to the brain.
This mutation could be carried by either parent or even both parents and passed on to their offspring. A parent may even be hearing and not know they’re a carrier of the mutation (more than 90% of babies with hearing loss are born to hearing parents, and TECTA-caused cookie-bite hearing loss is no exception).
Cookie-bite hearing loss may be present at birth or develop over time, becoming apparent in childhood or early adulthood. That said, cookie-bite hearing loss does appear to plateau: 96% of patients diagnosed with cookie-bite hearing loss do not exhibit any worsening of their auditory thresholds.
How Is Cookie-Bite Hearing Loss Treated?
Hearing aids are a common and effective way to manage cookie-bite hearing loss. These powerful devices pick up sound waves, process them digitally, sort them by frequency and amplify the pitches you need to hear. This makes them ideal for amplifying the mid-range sounds that are lost with cookie-bite hearing loss.
If you’re interested in learning more about cookie-bite hearing loss and how hearing aids can help, contact Heuser Hearing Institute. We’d be happy to answer your questions or schedule an appointment for a hearing examination.