An audiogram is the output – in the form of a graph – of a test performed to assess the state of your hearing, and to help determine whether you have suffered any hearing loss. The audiometry test is very quick and comfortable. The test measures your ability to hear sounds at various decibel levels and frequencies. On the audiogram graph, the Y or vertical axis represents the intensity of sounds that you were able to hear, measured in decibels (dB), from 0 (the faintest) to 100 (the loudest). On the other horizontal or X axis, you see the frequencies of different sounds, measured in Hertz (Hz); the frequencies range from 100Hz (the lowest bass frequency sounds measured in this test) to 8000Hz (the highest treble frequency sounds measured).
The specialist will then repeat the process starting with a tone at a new frequency. For each frequency tested, the volume at which you are first able to hear it is plotted on a chart – this is the audiogram. In theory, this line of dots should be fairly straight, showing that you heard all frequencies at about the same volumes, but even in people with perfect hearing there are always small variations. Deviations from normal in your audiogram give your audiologist information about what may be causing your hearing loss. For example not being able to hear low frequencies expect at very high volumes is associated with Hearing disease. Conversely, NIHL (noise-induced hearing loss) is associated with an inability to hear high-frequency sounds at low volumes. If you can’t hear sounds in any frequency except at higher volumes, that may indicate sensorineural hearing loss, such as that caused by otosclerosis.
These are just three example of data that your hearing specialist may glean from your audiogram. It is a vital tool in assessing the type of hearing loss you have and the treatments that are most suitable for you.