What is involved in a Hearing Test?

We will then perform a thorough hearing test, which will produce an audiogram showing whether you have a hearing loss or not, if the test indicates a loss we will be able to show and explain the extent of any such loss. Basically, the audiogram is the product of the hearing test, more precisely it is a graphical representation showing the loudness (intensity) levels at which specific pitches (frequencies) can only just be heard in each ear (hearing threshold), as well as some of the loudest sounds that we can hear without causing discomfort. The procedure for the audiometric test is:

  • Pure tones (beeps and buzzes) are presented to each ear via a set of headphones (air conduction test). The tones range from 250 Hz through to 8000Hz. These frequencies are used as they best represent everyday speech sounds and environmental sounds.

  • The person being tested either raises a hand or presses a response button every time a sound is heard or a sound is thought to be heard (the finger raised or button pressed should be for the duration of the tone presented).

  • The loudness of the tones are decreased until you can only just hear the sounds, this process will determine your hearing threshold.

  • The same procedure is then repeated by placing a bone conductor which fits behind one ear (on the mastoid process of the worse ear). The tones used for this test are only 500Hz, 1000Hz, 2000Hz and 4000Hz.

  • If necessary masking will then be applied. Masking is basically the blotting out of one cochlea response (through a distracting stimulus) while the opposite ear is tested in isolation.

  • Another test is also carried out, this is threshold of discomfort. The threshold of discomfort (TOD) or Uncomfortable Level (UCL) is the intensity (loudness) level of sound, which causes an awareness of the impending onset of physical discomfort (i.e. when sounds become too loud for physical comfort). In normal hearing people this is 120dB HL (threshold of pain being normally about 140dB HL).

  • All the results are recorded on the audiogram to produce a graphical representation of the test person's hearing.