An audiogram is a graph or picture that shows the results of a hearing test called “pure-tone testing”. The audiogram depicts your child’s hearing threshold, or the softest sounds that they are able to hear. The Speech Banana is an excellent resource that can help families visualize how speech sounds correlate to the audiogram. If a child is very young or is unable to clearly signal that they heard the beeps used during pure-tone testing, an audiologist may use different forms of testing such as auditory brainstem response (ABR) or otoacoustic emission testing (OAE).
The audiogram is often completed as a single part of an audiologic assessment, and audiologists will likely use a variety of additional testing methods to provide you with a report. For example, an audiologist may look inside of your child’s ear with an otoscope, check the pressure in your child’s ear, or test the acoustic reflexes of the ears. Each of these tests provide different information about the physical status of your child’s ear or the status of their hearing.
The numbers across the top of the audiogram represent frequency, or the perceived highness or lowness of a sound (pitch). Frequency is measured in Hz and sounds with a lower frequency will have a lower pitch while sounds with a higher frequency will have a higher pitch. An audiogram will depict frequencies of 250 hz (lowest pitch) to 8,000 hz (highest pitch), and your child will be tested in each octave (i.e. 250 hz, 500 hz, 1,000 hz, 2,000 hz, 4,000 hz, and 8,000 hz).
The numbers that run up and down the left side of the audiogram represent the intensity, or the perceived loudness or softness of a sound. Intensity is measured in dB and sounds with a lower dB are softer while sounds with a higher dB are louder.
Audiograms may have a variety of different symbols, and different clinics or hospitals may use their own set of symbols. However, the most important symbols for you to know are below.
Red O: Right ear
Blue X: Left ear
Normal hearing and degrees hearing loss:
According to the American Speech-Language-Hearing Association (ASHA), normal hearing falls between -15dB to +15dB. The categories for hearing loss are as follows:
Slight hearing loss: 16 to 25 dB HL
Mild hearing loss: 26 to 40 dB HL
Moderate hearing loss 41 to 55 dB HL
Moderately severe hearing loss: 26 to 70 dB HL
Severe hearing loss: 71 to 90 dB HL
Profound: 91+ dB HL (Clark, J.G. 1981)