An audiogram is a graph used to show the softest sounds that a person can hear at different pitches.
The graph shows the range of sounds included in typical speech. Different sounds in our language vary in their pitch and loudness. For example, the "s" you use in the word cats is high in pitch and fairly soft. In contrast, the "o" sound in bow is low in pitch and fairly loud. The frequency and loudness of individual speech sounds are shown on the audiogram.
Hearing is tested using earphones or loudspeakers. Sounds are sent to the ear canal and through the middle ear to reach the inner ear. This is known as air conduction testing.
If air conduction testing shows a hearing loss, another device, called a bone vibrator, is placed behind the ear to send sounds directly to the inner ear. The sound bypasses the ear canal and middle ear.
- In conductive hearing loss, sounds can be heard at softer levels with the bone vibrator than with the earphone
- In sensorinerual hearing loss, sounds are heard at similar levels through both devices