READING AN AUDIOGRAM

    Hearing is tested in many ways. One of the clinical methods used to test hearing (by an audiologist) provides an audiogram. An audiogram is a "graph" of your hearing. It shows the hearing sensitivity of each ear at different frequencies and different intensities. The graph indicates the softest sounds you can hear.

This is what a typical blank "graph" of an audiogram looks like:

        The numbers running from left to right across the top of the graph are the pitches you hear (frequencies). They run from low to high, from left to right, just like the pitches on a piano. These pitches are measure in Hertz (Hz). Typically in a standard audiogram the numbers start at 250 Hertz and continue up to 8000 Hertz. Hearing is commonly tested at the following intervals 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz and 8000Hz.

        The numbers running from the top to the bottom of the graph indicate loudness levels. They are measured in Decibels (dB). Numbers closer to the top relate to soft sounds (like a pin dropping) while numbers at the bottom refer to much louder sounds (like a plane flying overhead).

        It is important to note that hearing is NOT measured in percentages. The decibels (dB) are a arbitrary unit of measurement that is a logarithmic scale. Every 6dB increase measured represents a doubling of sound pressure level. To the human ear (perceptually), every 10dB increases sounds twice as loud. For example, 20 dB sounds twice as loud as 10dB but 40dB sounds twice as loud as 30dB and 8 times as loud as 10dB (i.e. 10 to 20 to 30 to 40 is 2 x 2 x 2=8times as loud). 

        An audiologist tests both ears. They mark each ears performance on the graph using this common code:

•  the left ear is marked with an X and is often represented in BLUE

•  the RIGHT ear is marked with an O and is often represented in RED

A typical audiogram may look like this:

   back to Hearing and Hearing Loss