Audiogram of Hearing Tests
The audiogram is a graph showing the results of the pure-tone hearing tests. It illustrates the type, degree, and configuration of hearing loss.
The frequency or pitch of the sound is referred to in Hertz (Hz). The intensity or loudness of the sound is measured in decibels (dB). The responses are recorded on a chart called an audiogram that shows intensity levels for each frequency tested.
Pitch or Frequency
Each vertical line from left to right represents a pitch, or frequency, in Hertz (Hz). The graph starts with the lowest pitches on the left side and moves to the very highest pitches (frequencies) tested on the right side. The range of frequencies tested by the audiologist are 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 3000Hz, 4000 Hz, and 8000 Hz.
Examples of sounds in everyday life that would be considered “low-frequency” are a bass drum, tuba, and vowel sounds, such as “oo” in “who.”
Examples of sounds in everyday life that would be considered “high-frequency” are a bird chirping, a triangle being played, and the consonant sound “s” as in “sun.”
Loudness or Intensity
Each horizontal line on the audiogram from top to bottom represents loudness or intensity in units of decibels (dB). Lines at the top of the chart (-10 dB and 0 dB) represent soft sounds. Lines at the bottom of the chart represent very loud sounds.
Examples of sounds in everyday life that would be considered soft are a clock ticking, a voice whispering, and leaves rustling.
Examples of sounds in everyday life that would be considered loud are a lawnmower, a car horn, and a rock concert.
If we were to compare “normal conversational loudness level” (typically 60 dB) with whispering (typically 30 dB), we’d say that whispering is softer than conversation.
On the audiogram, the pattern of hearing loss (configuration) and degree are recorded. For example, your hearing might be normal in the low pitches while you have hearing loss in high pitches. In this case, you might hear speech, but it would sound muffled and unclear. If you have hearing loss at all pitches, you might have difficulty hearing any speech.
The audiologist uses a red O to indicate the right ear and a blue X to record the left ear. The farther down the audiogram the Xs and Os appear, the worse the hearing.