An audiogram is a graph that charts what a person can hear. An audiogram also shows the type of hearing loss (conductive, sensorineural, or mixed), the degree of hearing loss (ranging from minimal to profound), and the pattern of the hearing loss (how much hearing loss exists at different frequencies).
The horizontal axis of an audiogram displays frequencies or pitch (high/low sounds). Pitch is measured from left to right starting from low frequencies (125 or 250 Hz) on the left side gradually climbing up to higher frequencies (8000 Hz) on the right side. Think of a piano keyboard, with the low notes (low pitches) are on the left and gradually moving up to the higher notes (high pitches) on the right.
The vertical axis displays intensity or loudness. The top of the audiogram starts with very soft sounds (-10 or 0 dB) and as you move down, you reach very loud sounds (110 dB).
Frequencies are measured using hertz (Hz) and loudness is measured using decibals (dB). The average standard audiogram uses frequencies starting at 125 Hz up to 8000 Hz and decibels starting at -10 dB up to 110 dB. The higher the number of decibals, the louder the sound. The louder the sounds must be in order to be heard, the greater the degree of hearing loss. Similarly, the lower the pitch the lower the frequency (100 or 125 Hz) and the higher the pitch the higher the frequency (8000 Hz).
Threshold is defined as the softest sound a person can hear, and is measured in decibels (dB). Thresholds are measured at several frequencies (pitches) and graphed on the audiogram. The frequencies tested are those important for hearing and understanding speech and other environmental sounds.
Symbols are used to represent what ear is being tested and what each ear hears at the various levels. An "O" is used to represent the right ear and an "X" is used to represent the left ear. An "A" (Aided) is used to represent an ear tested with a hearing aid on.
