Audiograms are an easy way to visualize your hearing ability as they can be compared to a normal hearing range. The results displayed by your audiogram are incredibly useful as they indicate to your doctor not only whether you have hearing loss, but also the severity and medical properties.
How Are Audiograms Made?
Audiograms are created by plotting the thresholds at which you can hear various frequencies. The X-axis represents frequency or pitch. Low frequencies start on the left side of the graph and each line to the right represents a higher frequency (just like if you were playing the piano). The frequencies tested are 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 3000Hz, 4000 Hz, and 8000 Hz.
The Y-axis on the audiogram represent loudness or intensity. The zero decibels (dB) line is located at the top of the audiogram and denotes a sound that is barely audible. The lines below represent louder and louder sounds. The softer the sounds you can hear, the closer the marks will be to the top of the graph.
During the hearing test, you will be asked to raise your hand or push a button in response to the sounds that you hear. The audiologist notes the loudness of the sounds heard at each frequency. The audiogram displays what you heard.
An ‘O’ is often used to map responses for the right ear and an ‘X’ for the left ear. The audiogram will show how loud sounds must be at different frequencies for you to hear them. Where your results fall on the audiogram indicate the different degrees of your hearing loss. The type, degree, and configuration of your hearing loss can be interpreted by the audiologist.
What Does Your Audiogram Look Like If You Have Hearing Loss?
The audiogram shows the pattern of your hearing loss as well as the degree of your hearing loss (the severity). Put simply, if the ‘X’s and ‘O’s are at the top of the graph, you have normal hearing. When the ‘X’s and ‘O’s are farther down the graph, you have hearing loss.
Your hearing might be normal for certain pitches but poor for others. For example, you can have normal hearing for low pitches but not for high pitches. There are many different types of hearing loss!
Humans can generally hear between 20 and 20,000 Hz. However, audiograms usually test frequencies between 250Hz and 8000Hz, mainly because human speech falls between 250Hz and 6000Hz.
Mild hearing loss is indicated by the 20 – 40 dB range and is characterized by an inability to hear soft sounds. Moderate loss (difficulty hearing some quieter conversations) occurs at 41 – 55 dB, moderate-severe loss (difficulty hearing a normal conversation) occurs at 56 – 70 dB, severe loss (understanding speech only if the speaker is in close proximity) is shown at 71-90 dB, and profound (inability to even hear loud stimuli) is anything over 90 dB.
If your audiogram indicates that you have hearing loss, your audiologist will be able to talk you through the details of your individual case. They’ll explain the breakdown of your results and discuss the treatment options available to you.
Hidden Hearing Loss and Audiograms
Audiograms are incredibly useful tools. However, they won’t show if you have hidden hearing loss, as this is not detectable through standard hearing tests that focus on issues with the ear.
While ordinary hearing loss occurs due to damage to the hair cells or the nerves. Hidden hearing loss occurs as a result of a loss of synapses in between. The signal arrives at the brain incomplete, and we don’t have the information needed to interpret words. Repeated exposure to noise is thought to be one of the most common causes of hidden hearing loss.
In the audiologist’s quiet testing room, you only need a few synapses to pick up sounds. This means that people with hidden hearing loss can appear normal on a hearing test, but when they’re in a noisy environment and the ear must activate specific synapses, they struggle to hear.
Instances of hidden hearing loss are more common than you might think. A study of more than 100,000 patient records over 16-years shows that around 10% of patients who visited the audiology clinic at Massachusetts Eye and Ear had a normal audiogram despite their complaints of having hearing difficulties. Fortunately, this means that audiologists are well aware of the possibility of their patients having hidden hearing loss.
Although there is no direct treatment, promising research is underway to find medications that can prompt synapse growth and effective methods of diagnosis. In the meantime, there are assistive listening devices and other alternatives available to help assist you.
The information in this guide has been written using the following reliable sources: