An audiometry test is performed to determine how well you can hear. This may be done as part of a routine screening or in response to a noticeable loss of hearing. A machine called an audiometer will play a series of tones through headphones. The tones vary in pitch (frequency, measured in hertz) and loudness (intensity, measured in decibels). The health professional conducting the test will control the volume of a tone and reduce its loudness until you can no longer hear it. Then the tone will get louder until you can hear it again. You signal by raising your hand or pressing a button every time you hear a tone, even if the tone you hear is very faint. The health professional will then repeat the test several times, using a higher-pitched tone each time. Each ear is tested separately.