An Audiogram is a chart of hearing ability.
A profile of hearing ability is recorded on a chart called an Audiogram. Typically, an audiogram has numbers across the top which show each frequency (pure tone) that will be sampled. For example they might include: 125, 250, 500, 1000, 2000, 4000 and 8000 Hz.
On the left, going down the side, would be the intensity, marked off in decibels relative to threshold, required for a person to hear each pure tone at threshold.
These might include: -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 dB.
A series of pure tone are presented with increasing intensity. The individual raises his hand when he finally hears it. Most audiograms use an "X" to show the threshold for the right ear and an "O" for the left ear.
If one connects the points with a line, a profile of hearing is apparent. In the following audiograms you can see the high frequency loss in the profile.