How to read your audiogram

The two axes

Along the top, from left to right, is pitch, measured in hertz (Hz). Low-pitched sounds, like a deep voice or a drum, are on the left, around 250 Hz. High-pitched sounds, like birdsong or the s in speech, are on the right, up to 8,000 Hz.

Down the side, from top to bottom, is loudness, measured in decibels hearing level (dB HL). The top of the chart is very quiet. The further down a mark sits, the louder a sound had to be before you heard it.

The symbols

• O, usually red: your right ear, tested through headphones (air conduction).
• X, usually blue: your left ear, through headphones.
• < and >, or [ and ]: bone conduction, tested with a small vibrator behind the ear, which bypasses the outer and middle ear.

Levels of hearing loss

• Up to 20 dB: within the normal range.
• 21 to 40 dB: mild hearing loss. Soft speech and conversations in noise are harder.
• 41 to 70 dB: moderate. Normal conversation is difficult without hearing aids.
• 71 to 95 dB: severe. Even loud speech is hard to hear.
• Above 95 dB: profound.

What the pattern tells you

A line that slopes down to the right is the most common pattern, high-frequency hearing loss, usually from age or noise. A gap between the headphone and bone conduction results points to a conductive loss, such as wax, fluid or otosclerosis. When both sit together, the loss is sensorineural, in the inner ear. A clear difference between your two ears is worth investigating further.