The chart above is an example of an audiogram which is used to plot the results of a hearing test and to establish your hearing threshold. Hearing is tested at different frequencies – usually from a low tone of 250 Hz (hertz) up to 8000 Hz and aims to affirm the quietest sound heard at each frequency. The sound levels are measured in decibels (dB) which are found on the vertical line of the audiogram. The results of your hearing test are then plotted on the audiogram and this is known as your hearing threshold.
The audiogram chart above, gives an indication of the different every day noises and the sounds that make up speech. They have been plotted at approximately the frequency and sound level you would expect to find them. Your hearing threshold is an indication of the minimum volume levels you can hear at a particular frequency which is then noted on the chart. The line across, charts the shape of your hearing loss and is often used in the description of your loss. An example of this is a ski slope hearing loss – which is good to normal low frequency hearing which drops off steeply after 1000Hz to a severe to profound loss in the higher frequencies.
-10dB 20dB across frequency range
High frequency loss
Normal hearing to 1000 – 2000Hz and then dropping off in the higher registers.
Reverse slope loss
Normal hearing in high frequencies and then dropping off
Cookie bite loss
Normal hearing in high and low frequencies with a dip in mid range frequencies
Ski slope loss
Steep high frequency loss
Mild hearing loss
40 – 70dB loss across frequency range
Moderate hearing loss
70 – 90dB loss across frequency range
90+dB loss across frequency range
Asymmetrical hearing loss
Marked difference between left and right ears
Unilateral hearing loss
Recordable hearing on one side only.