July 2020 Healthy Hearing (Madeleine Burry)
If you have mid-range hearing loss, your audiogram will be shaped like a bell, or the letter U. This is also known as cookie-bite hearing loss. “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,” explains Dr. Jordan Glicksman, MD, MPH, FACS, FRCSC, an otolaryngologist, rhinologist and skull base surgeon, and a part-time lecturer at Harvard Medical School.
Cookie-bite hearing loss is a type of sensorineural hearing loss—that means it’s due to an impairment in the cochlea or auditory nerve, and not a conductive problem (such as fluid in the middle ear or earwax build-up), Dr. Glicksman says. This type of hearing loss is far less common than other types of hearing loss, such as age-related hearing loss, he says. Human ears can normally hear a wide range of pitches, from low to mid to high. But if you have cookie-bite hearing loss, your ability to hear mid-range hearing frequencies will be affected. A lot of human speech and music is in the mid-range, between 500 Hz and 2,000 Hz.
Your high-frequencing hearing is not affected, so you’ll still be able to hear high-frequencies noises (i.e., higher pitch sounds like women and children’s voices and bird chirping). And, you’ll also still be able to hear low-frequency sounds (low-pitched sounds such as thunder or a man’s voice).
Since you can still hear those frequencies, you may still be able to figure out what people are saying, even if you’re not hearing fully, notes Gallaudet University’s Laurent Clerc National Deaf Education Center.
As with many forms of hearing loss, it may be the people around you—your friends and family—who first suspect you’re having difficulty hearing.
You may find yourself raising the volume on the TV or radio, experiencing reduced clarity, or having difficulty hearing in a crowd, says Dr. Glicksman. “Since speech frequencies are commonly affected patients can have communication difficulties if the loss is severe,” he adds. Typically, cookie-bite hearing loss is a genetic condition, Dr. Glicksman says. “A family history is a risk factor,” he says. Cookie-bite hearing loss can be congenital or develop over time due to genetics, he says. There are some less common reasons cookie-bite hearing loss is developed beyond genetics. For instance, a rare benign tumour, known as vestibular schwannoma or acoustic neuroma, can lead to this mid-frequency hearing loss, Dr. Glicksman says.
The diagnosis process for this form of hearing loss is simple: An audiogram will reveal the distinctive pattern that points to cookie-bite hearing loss. In fact, the biggest challenge for diagnosis may be requesting the test. “It’s commonly a mild form of hearing loss,” Dr. Glicksman says. That could make people slow to realise that their hearing has worsened, and result in them not having the audiogram performed early on. Plus, he notes, this mid-range frequency loss can occur over a long period of time, as opposed to a sudden hearing loss, which might be more noticeable.
No cure exists for cookie-bite hearing loss—there’s no surgery or medication that will restore a person’s hearing abilities. However, there are treatment options available to help manage the condition. They depend on how severe the hearing loss is, and how eager someone is to rehabilitate their hearing, Dr. Glicksman says.
- Making adaptations: Simple changes, such as changing where you sit in restaurants and other social gatherings, as well as in classrooms, can be helpful, says Dr. Glicksman. Aim to move close to the person speaking, or make sure you can easily see their lips. If a person is speaking into a microphone, moving closer to the amplification device can be helpful, he notes.
- Hearing aids: Wearing hearing aids can help amplify the mid-frequency sounds