What is a Hearing Test/Audiogram?

An audiogram is a graphical representation of hearing. It is used to diagnose the type and degree of hearing loss and monitor a patient’s hearing status over time. There are three types of hearing loss: conductive, sensorineural & mixed. The audiogram displays the results for each ear and tells the audiologist the softest sound that a patient can hear at each frequency.

Frequency:

Hertz (Hz) is the unit of frequency or pitch. The audiogram shows frequencies from low pitch through high pitch. They are read from left to right. Each vertical line represents an individual frequency such as 250, 500, 1000, 2000, 4000, 6000, and 8000 Hz.

Intensity:

The intensity of a sound is measured in decibels (dB). Intensity refers to the volume or softness of a sound. Each horizontal line indicates a different level of intensity. The chart shows the lowest intensity sounds at the top while the highest intensity level at the bottom of the graph. The lowest intensity is usually 0 dB, while the loudest is 120. The audiogram will show you the softest sounds a person can hear.

Right Ear vs Left Ear

The audiogram will show the results of the hearing test for the right ear with either an O or a triangle and the left ear with either an X or a square. These are the results of air conduction, meaning testing performed using inserts, or headphones.

The results of the hearing test completed through speakers, also known as sound field, are marked “S” on the audiogram. This indicates the response of only one ear or the better-hearing ear.

You may also see other symbols on the audiogram that indicate responses to bone conduction testing or testing of only the inner ear. This is performed using a special headband called a bone oscillator. These responses will help determine if the hearing loss is conductive, sensorineural, or mixed and are represented by a less than/greater than symbol or a bracket.