An audiometry exam tests your ability to hear sounds. Sounds vary based on their loudness (intensity) and the speed of sound wave vibrations (tone). Hearing occurs when sound waves stimulates the nerves of the inner ear. Eventually the sound travels along nerve pathways to the brain. Sound waves can travel to the inner ear through the ear canal, eardrum, and bones of the middle ear (air conduction), or through the bones around and behind the ear (bone conduction).
The first steps are to see whether you need an audiogram. The specific procedures may vary, but they generally involve blocking one ear at a time and checking your ability to hear whispers, spoken words, or the sound of a ticking watch. A tuning fork may be used. The tuning fork is tapped and held in the air on each side of the head to test the ability to hear by air conduction. It is tapped and placed against the mastoid bone behind each ear to test bone conduction.
Audiometry provides a more precise measurement of hearing. To test air conduction, you wear earphones attached to the audiometer. Pure tones of controlled intensity are delivered to one ear at a time. You are asked to raise a hand, press a button, or otherwise indicate when you hear a sound.
The minimum intensity (volume) required to hear each tone is graphed. An attachment called a bone oscillator is placed against the bone behind each ear (mastoid bone) to test bone conduction.