How Does Sound Function?

“I’m sorry, I don’t understand—can you repeat that?”

Have you caught yourself saying something similar? You can hear someone talking, but their words are not clear; you can’t understand them.

Hearing loss is tricky. When people have issues with their hearing, they are quick to blame the issue on a circumstance such as background noise or to accuse someone of mumbling. However, blaming the issue on your environment or your loved ones won’t solve the problem. If you have a problem seeing clearly, you don’t blame your surroundings for being blurry. Instead, let’s try to understand the extent of your hearing loss and why it has happened. How does sound function?

Anatomy

When sound waves enter your ear, they are “caught” by your eardrum, resulting in the movement of the three smallest bones in your body, the incus, malleus, and stapes. (You may have seen these tiny bones referred to as the hammer, anvil, and stirrup, respectively)  The stapes moves the oval window which is located on the vestibule of the inner ear. The cochlea, located within the inner ear vestibule, is the spiral-shaped organ that amplifies sound waves into signals the brain can interpret. Inside the cochlea are about 1500 hair cells. Hearing loss results when the hair cells inside the cochlea become damaged and can no longer change sound waves into signals that your brain can interpret. Most of us who experience hearing loss due to genetics or noise exposure (nerve/hair cell damage), have only a partially damaged cochlea. This means that only certain frequencies are hard to hear, not all of them.

Frequencies

An audiogram is usually composed of frequencies from 250 to 8000 Hz. Low frequencies are on the left side at 250 Hz, and high frequencies on the right side at 8000 Hz. One of the most common types of hearing loss is called high-frequency hearing loss. This means a person can hear low frequencies but cannot hear higher pitches clearly.

A high-frequency hearing loss for some people is harder to recognize because they perceive low frequencies as normal. However, being able to hear low frequencies doesn’t mean you don’t have another form of hearing loss.

Speech and Frequencies

To better understand this point, think of the English language. The word “cat” is made up of a vowel and two consonants. The “a” sound is a low pitch that is easier for most people to hear. However, the “c” and the “t” is not easily heard if you have high-frequency hearing loss because they create a soft, high-pitched sound. This is why many people with hearing loss can hear, but they do not understand. They can hear part of the word, but not all of it. They must understand based on context alone – “Is she talking about my hat? Or our friend named Pat?”

Everyone Mumbles

Many people with hearing loss complain that other people mumble too much. This is because people with high-frequency hearing loss hear low frequencies better than the high-pitched ones. They may hear the vowels, but not the higher-pitched consonants, resulting in mumbled sounds. The sentence “I took my hat off” without any consonants sounds like, “I OO MY A AW.” That definitely seems like mumbling to me.

Baseline Hearing Evaluation

Now that you understand frequencies and the basics of hearing loss, you no longer have to wonder, “Why can I hear you but not understand you?” Even if you do purchase hearing aids, you may have difficulty re-learning the information your brain has been deprived of for so long. Because of this, getting an annual or biannual baseline hearing test is important. Even if you experience slight hearing loss, you may not be the ideal candidate for hearings aids. Having routine checks provide a foundation for understanding your hearing loss as it progresses over time.

Book Your Baseline Hearing Evaluation Today!

At Hearing Resources Audiology Center, it is our mission to create awareness for hearing loss and to provide exceptional treatment. Let’s get you reconnected to the beautiful sounds around you.