How are Audiometry Tests Interpreted?

an audiologist is explaining the results of a hearing exam to her patient

Audiologists use audiometry tests to verify the severity and type of hearing loss and give your audiologist the information required to determine the most appropriate course of action to manage your hearing issues.

If you are unfamiliar with the result and chart or graph, you may find yourself at a bit of a loss. It can often look like a bunch of lines and marks that are seemingly impossible to decipher. However, when you have learned how to interpret and read an audiometry test, you are in a much better place to understand your hearing loss. Even more importantly, your audiologist can make decisions based on it that will improve your hearing and overall quality of life.

What is an audiometry test?

The aim of an audiometry test is to measure your hearing ability over a range of frequencies each ear. The results of this test are plotted into a chart called an audiogram. 

An audiogram plots the threshold of your hearing across various frequencies in a quiet environment. By hearing threshold, we mean the softest sound that you can detect. It is important to remember that the results of an audiometry test are quantitative rather than qualitative. It does not describe your hearing loss or hearing ability subjectively. Instead, it is a very particular numerical system to measure your residual hearing in a quiet environment.

What do the marks and lines mean?

The left axis of your graph refers to the volume and intensity of the sounds that you heard during your test. The softer sounds are at the top, and the louder ones are at the bottom. The sounds are measured in decibels (Db). To give you an idea, a whisper is around 30 Db, whereas a rock concert is between 110 and 140 Db.

The right axis indicates the frequency or the picture of the sounds. Sound waves are measured in hertz or kilohertz, named after the German scientist Heinrich Hertz, who looked into electromagnetic waves in the 1880s. A typical range of hearing is 20 Hz to 20000 Hz, but the average person’s most sensitive hearing range is between 2000 and 5000 Hz.

Your audiologist will play tones and varying frequencies and volumes through headphones and plot your response on the graph. These are then measured against a standardized curved to determine the extent and nature of your hearing loss.

Standard audiometry tests use red circles to represent the right ear results and blue crosses to mark the left ear results. Each of these marks indicates both the frequency level and the volume at which you were able to hear that sound.

Normal hearing results are shown in the top fifth of the graph. Someone with no hearing issues should be able to hear all the sounds from 250 Hz to 8000 Hz at a relatively quiet volume. Any results below the 20 Db line may indicate a hearing loss. The more significant the drop, the more profound the hearing loss.

What do the results tell us?

When people see their audiometry test results, they are often surprised. People tend to wait, on average, seven to ten years before having their hearing checked after first noticing an issue. By the time the test is done, the hearing loss is usually a lot worse than expected. This because hearing loss is gradual in most cases, and our brain adapts brilliantly, so we do not notice the decline.

Typically, the sensitivity for higher frequency sounds is first to go. The high-frequency cells are damaged more easily because of the location in the cochlea than the lower frequency cells. Higher frequency hearing loss is often caused by excessive loud noises, ototoxic drugs and the aging process.

Most people will see a downward curve, especially when looking at the higher frequencies. The important thing to be aware of is the volume at which your own hearing curve starts and how drastically it drops down. This will help you to understand the overall extent of your hearing loss, from mild to profound. 

Do not worry if you do not understand your chart and audiometry test results. Your audiologist will and should be explaining them to you along with the plan of action for managing your hearing loss. However, do not be afraid to ask questions and for clarification on anything you do not understand or that concerns you. Having a deeper understanding of your results allows you to gain more control over your treatment and the steps that you will be taking towards better hearing. 

If you want further advice on hearing loss or audiometry tests, the hearing experts at Valley Heating Center can help. Call us today at 831-240-4162.