Ear, Nose and Throat Group, Inc.

Understanding hearing loss becomes much easier if we know a little more about the mechanics of hearing.

Sound waves of pressure enter the ear and vibrate our eardrum and tiny middle ear bones. These vibrations are then sent to the inner ear structure. This snail shaped organ, if unrolled, is like a keyboard with “hair cells” or receptors from low to high pitch tones that, when moved or pressed, send impulse signals via the nerve to our brain.

To detect hearing loss, we conduct our tests in sound treated booths to provide accurate results. Patients respond when they hear sounds transmitted through insert earphones at the different tones (or frequencies) and volumes (decibels or dB). We plot the responses on a graph or “audiogram”.

The responses are plotted with the tones from low to high pitch across the top. The numbers on the side reveal how loud the decibels or dB are needed for a patient to hear. From the top of the chart to 25 dB is normal hearing. The chart below depicts a hearing test with normal hearing in the low frequencies sloping to a moderate degree of loss for the high pitched tones.

This type of loss causes problems because the parts of speech are not evenly distributed across the frequency range. Our normal speech distribution is called a “speech banana” because of the shape; the low pitched tones are strong– like our vowels a, o, e.

The high end of the “banana” shows the weaker consonants like the f, sh and t sounds. These are the crucial sounds we need to distinguish one word from another. When we lose these critical high pitched tones, it seems like we “hear the words but cannot understand them” because we need the consonants or high pitched tones to help differentiate one word from another.

Just by virtue of the coiled organ’s position, loud sounds damage these high-frequency hair cells first which results in hearing loss which is additive and cumulative over our lifetime. Likewise, these high frequencies are vulnerable to aging as well as from certain types of drugs and other agents. These “keys” on the keyboard or hair cells do not grow back and cannot be replaced.

When a significant hearing loss occurs, hearing aids improve the audibility and perception of these signals so that poor communication struggles can be improved.

In fact, since 95% of all hearing losses cannot be medically or surgically treated, hearing aids become the only realistic option for improving hearing ability.

At the Ear, Nose and Throat Group, Inc. our Board Certified Doctor of Audiology professionals can assess your hearing loss and communication abilities. After review, the audiologist will then recommend the treatments and technologies that are appropriate for you and your loved ones.

By Marilyn A. Gresham, Au.D. - Marilyn A. Gresham, Au.D., Director of Audiology, earned her Masters degree at the University of Memphis and a Doctor of Audiology degree from the University of Florida in 2000. She has been a practicing audiologist for over 25 years, is licensed by the State of Tennessee, and certified by the American Speech & Hearing Association. She is a Board Certified Fellow of the American Academy of Audiology.