Have you ever struggled to hear certain sounds or distinguish between similar-sounding words? Do you find yourself constantly turning up the volume on the TV or radio? 

These could be signs of hearing loss, a common condition affecting millions worldwide. But what if your hearing loss is not like the typical high or low-frequency loss but rather a unique pattern in the middle frequencies? 

This is where cookie bite hearing loss comes into play. What exactly is cookie-bite hearing loss, and how does it differ from other types of hearing loss? What are the symptoms and causes, and how is it diagnosed and treated? 

In this article, we will delve into the world of cookie-bite hearing loss and provide answers to these questions and more. Relax and find out more about the salient facts of cookie-bite hearing loss.

cookie bite hearing loss

Cookie Bite hearing loss is a type of sensorineural hearing loss. What this means medically is that this problem arises primarily due to defective function of the auditory part of the vestibulocochlear nerve and not from conduction defects of the conducting system of the ear. 

But why is it referred to as cookie-bite hearing loss? 

On an audiogram, your hearing ability is affected in the middle frequencies, particularly between 500Hz-2000Hz. This results in a U-shaped curve that appears as a bitten cookie and thus the name. 

Cookie Bite Hearing Loss Audiogram Credit: Florida Hearing Institute

What this means is that if you have cookie-bite hearing loss, you can hear low-frequency sounds like thunder and high-frequency sounds like birds chirping, but you cannot hear sounds in the mid-range frequencies between 500 Hz and 2,000 Hz.

This can make it difficult to hear many speech sounds and music that occur in this frequency range. Although you may be able to hear people talking with normal hearing in the low and high frequencies, you may struggle to understand what is being said due to the missing mid-range frequencies.

cookie bite hearing loss

Cookie bite hearing loss is a very rare form of hearing loss forming 0.7–1% of all sensorineural hearing loss cases and affecting 5 – 15% of children with hearing loss

It is thought to be caused by a combination of genetic and environmental factors. The genetic component is largely implicated as it has been shown to run in families due to the inheritance of certain genetic mutations. In these cases, it is seen to have a delayed onset as compared to other genetic forms of hearing loss.

However, it is not always a case of genetic mutations; sometimes, it can be acquired. For instance, in some medical conditions such as Meniere’s disease and otosclerosis, cookie bite hearing loss can develop gradually. The damage caused by the disease process of both diseases is the factor of concern here. The good news, however, is that early diagnosis and treatment can help prevent or slow down further hearing loss.

Additionally, exposure to loud noise, certain medications, and aging can also contribute to the development of cookie-bite hearing loss. In some cases, the cause of the hearing loss may not be identified.

Also, mid-frequency hearing loss can be caused by an acoustic neuroma, which is a benign tumor, albeit in rare cases.

cookie bite hearing loss

Just as with all other forms of hearing loss, it is those around you – friends and family – that suspect that you have difficulty hearing.

However, what are the tell-tale symptoms of cookie-bite hearing loss? 

Symptoms may differ from person to person, but the most typical thing is difficulty hearing mid-frequency range sounds. This can manifest as a reduced perception of speech, music, and environmental sounds, resulting in increased TV or radio volume due to decreased hearing of certain speech sounds, as well as difficulties hearing in social and crowded environments especially struggling in background noise.

The presence of background noise can particularly obscure speech sounds in the mid-frequency range, thus making it more challenging to perceive these sounds. This can be quite exasperating as it requires extra listening effort to decipher the words instead of fully engaging in the conversation.

cookie bite hearing loss

Typically, a hearing test is conducted to diagnose cookie-bite hearing loss, and an audiogram is drawn and interpreted to show the presence of disease. 

However, how is it done? To categorize broadly, there are two types of tests: genetic and hearing tests.: 

  1. Genetic tests – Scientists have identified over 130 genes that may cause cookie-bite hearing loss. While research on this is not definitive, there are available protocols that can be used to identify the said gene anomalies in hearing loss. As such, cookie bite hearing loss can be detected via genetic testing.
  2. Hearing tests – are common and come in various types of hearing tests. The use of this test is dependent on age.
    • Otoacoustic emissions – are usually done in cases where young children cannot undergo a traditional behavioral hearing test, and as such otoacoustic emissions (OAEs) are used to provide an objective measure of hearing. This test involves playing sounds in the ear and recording the sound sent back by the inner ear. If this sound is recordable, it indicates normal inner ear function and rules out anything more than mild hearing loss.
    • Auditory Brainstem Response (ABR) – ABR testing measures the hearing nerve’s response to sounds and is typically performed under sedation for children over six months old. For younger children, an unsedated test is possible if they are tired and able to sit still or sleep. An earphone is placed in the ear, and stickers are attached to record the nerve’s responses. The results can help determine the severity of a child’s hearing loss and guide the fitting of hearing aids.
    • Visual Reinforcement Audiometry Test – Around 18 months of age, children become capable of participating in different types of hearing tests. One such test is known as visual reinforcement audiometry (VRA), which involves a “game” where the child hears a sound from either the right or left ear, followed by a visual cue such as a cartoon or animated toy. The child turns their head towards the sound in anticipation of the fun visual. If these head turns to occur in response to sounds within the normal hearing range, it indicates normal hearing in at least the better ear.

For older children who can tolerate wearing headphones, ear-specific information can be collected through a type of hearing test called conditioned play audiometry. In this test, the child plays a game, listens for beeping sounds, and then puts blocks or toys into a box when they hear them.

  • Traditional Hearing Tests to Diagnose Cookie-Bite Loss- this is a conventional hearing test that is available for adults and older children, which involves listening for beeping sounds and pressing a button or raising their hands when they hear them.

The test consists of three components: air conduction testing (listening to beeping sounds with headphones), bone conduction testing (listening to beeping sounds with a headband), and speech testing (repeating words).

cookie bite hearing loss

Unfortunately, there is no cure for cookie-bite hearing loss. Not even surgery. However, there are options available for managing the situation. These include making simple life adaptations and use of hearing aids.

For simple adaptations, you can begin by moving closer to the speaker and watching your friends’ lips as they speak. This will go a long way to help one understand what is being said by the other party.

However, it is highly recommended that you get hearing aids as they will increase the frequency of mid-frequency sounds for you to hear better.

Here are seven interesting facts about cookie-bite hearing loss:

  1. Cookie-bite hearing loss is a rare form of hearing loss, accounting for only 0.7-1% of all sensorineural hearing loss cases.
  2. The name “cookie bite” comes from the shape of the hearing loss on an audiogram, which looks like a U-shaped bite taken out of a cookie.
  3. People with cookie-bite hearing loss can hear low-frequency sounds and high-frequency sounds, but they have difficulty hearing sounds in the mid-frequency range between 500 Hz and 2,000 Hz.
  4. Cookie bite hearing loss is primarily caused by genetic factors, but it can also be acquired through exposure to loud noise, certain medications, and aging.
  5. Symptoms of cookie-bite hearing loss include difficulty hearing mid-frequency range sounds, reduced perception of speech and music, and difficulty hearing in social and crowded environments.
  6. Cookie bite hearing loss can be diagnosed through hearing tests like otoacoustic emissions and auditory brainstem response, as well as genetic testing to identify gene anomalies.
  7. Early diagnosis and treatment of cookie bite hearing loss can help prevent or slow down further hearing loss.
Medical Doctor (MBBS) at Faculty of Medicine, University of Colombo, | + posts

Dr. Dolapihilla is a medical doctor (MBBS) and a research assistant at the Faculty of Medicine,
University of Colombo, Sri Lanka. She is a clinical research physician-scientist and an
enthusiastic academic writer with over 6 years of experience in clinical research.

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