What is an audiogram? In short, it is a useful tool that audiologists use to help people understand their hearing loss by providing a graph or chart that displays the results of their hearing test. Audiograms show your hearing threshold, which is the quietest sound you can hear at least half the time, across various speech frequencies.
Audiograms are quantitative, not qualitative, in that they use a specific numerical system to measure hearing ability in a quiet testing room, not subjectively describe the quality of your hearing in different environments.
Axes on Audiogram
Audiograms have two axes.
The horizontal axis (x-axis) represents frequency, which is measured in hertz (Hz) and is ordered lowest to highest, like keys on a piano. The lowest frequency that appears is typically 250 Hz, while the highest is 8000 Hz. This range encompasses most speech frequencies.
The vertical axis (y-axis) represents volume (or intensity) and is measured in decibels. The lowest decibels appear at the top of the graph, while high decibels are at the bottom. The decibel range usually starts at -10 or 0 dB, which are the quietest sounds people with healthy ears can hear, and goes up to 120 decibels, which is the threshold where sounds become uncomfortably loud.
Colors and Symbols on Audiogram
Responses from the left ear are represented with a blue line, and responses from the right ear are represented with a red line. If the two lines more or less overlap, your hearing is consistent in both ears. If they don’t overlap, it means your hearing is asymmetrical and you have different hearing ability in each ear.
There are several symbols used to indicate hearing thresholds on an audiogram that are based on the types of test used. Air conduction testing results are indicated with a red “O” for the right ear and a blue “X” for the left ear. Bone conduction testing is indicated with the symbols “[“ or “<”.
How Audiograms Indicate Degree of Hearing Loss
The topmost space above the 25-dB mark represents normal hearing. If the line or any symbols on your audiogram are below this threshold, it indicates a loss of hearing. Hearing loss is classified as slight, mild, moderate, moderate-to-severe, severe and profound, and can present as flat, sloping or rising. Your audiologist will go over what these results mean in terms of your quality of life and treatment options.
To schedule a hearing test or to learn more, call the experts at ENT of Georgia today.