Have you ever heard the term “cookie-bite hearing loss?” This sweet-sounding term describes a rare type of hearing loss in which the ability to hear mid-frequency sounds is much lower than high- and low-frequency sounds. More officially, cookie-bite hearing loss is called mid-frequency sensorineural hearing loss, or MFSNHL.
The Audiogram and Visualizing Hearing Loss
To understand cookie-bite hearing loss, let’s quickly review what an audiogram is. When you complete a hearing test, your test results are printed out on a chart called an audiogram. Every sound audible to the human ear can be mapped on this chart, with the horizontal (x) axis representing frequency in Hertz (Hz) from low to high and the vertical (y) axis representing volume in decibels (dB) from soft to loud.
Your hearing ability will be imposed on this graph. Points will be placed that indicate the softest volume at which you can hear each pitch. Keep all this information in mind, as it will help contextualize cookie-bite hearing loss.
What Makes Cookie-Bite Hearing Loss Unique
Everyone experiences hearing loss in their own unique way, but there are certainly patterns. Generally speaking, hearing loss progresses starting with the high-frequency noises, especially with age-related hearing loss (presbycusis) and noise-induced hearing loss (NIHL).
As the name “mid-frequency sensorineural hearing loss” might suggest, with cookie-bite hearing loss, hearing loss is most pronounced with the mid-frequency sounds. It is quite rare, with a reported prevalence of 0.7%.
What It Looks Like on an Audiogram
For someone with healthy hearing abilities, their audiogram will have an almost flat line running across the top of the chart, showing that they can hear all sounds quite well at low volumes. For presbycusis, NIHL and most other types of hearing loss, the line will start to slope downward on the right side of the chart, indicating that they struggle the most with high-frequency sounds. The more severe the hearing loss, the steeper this slope and the lower the top of the line will be.
With cookie-bite hearing loss, the line on the audiogram dips in the middle. In fact, this is where cookie-bite hearing loss gets its moniker, as it looks like a bite was taken out of it.
What It Sounds Like
Imagine a symphony: a wide variety of instruments such as tubas, violas and flutes span a range of pitches and work together to create beautiful music. Someone with presbycusis or NIHL will struggle to hear the higher instruments, such as the flutes. Someone with cookie-bite hearing loss, however, will hear the flutes but struggle to hear the mid-range instruments, such as the violas and woodwinds.
The mid-range of frequencies is also where most of human speech can be mapped. This means that people with cookie-bite hearing loss will have an especially hard time hearing people speaking to them.
What Causes It
As mentioned, cookie-bite hearing loss is a rare form of hearing loss. Typically, it’s a genetic condition. It can be congenital, meaning that it’s present at birth, or it can develop gradually as you grow up, but it is almost always caused by a genetic mutation passed from parent to child (even if the parent shows no symptoms).
Treating Cookie-Bite Hearing Loss
Cookie-bite hearing loss is commonly managed with hearing aids. These powerful devices pick up sound waves and process them digitally, sorting them by frequency and amplifying the pitches that you need to hear. This makes them ideal for amplifying the mid-range sounds that cookie-bite hearing loss diminishes.
If you’re interested in learning more about MFSNHL or hearing aids, contact Carolina Ear Nose & Throat – Sinus and Allergy Center today.