Hearing Loss/Diagnosis
Pure Tone Audiogram:
The hearing test is plotted on an audiogram which shows the degree of hearing loss (dB or decibel on the vertical axis) for individual frequencies (Hz or Hertz on the horizontal axis). The range frequencies tested (pure tones) is usually 250Hz – 8 KHz. This is the range of frequencies which is important for speech recognition.
Conductive Loss
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Sensorineural Loss
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Mixed loss
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Speech Audiogram:
This is a graph which shows the percentage of correct words repeated on the vertical axis against the presentation level (volume in dB). There is usually close correlation between the speech audiogram and the pure tone audiogarm.
Tympanometry:
Is another test performed routinely, especially in younger children. This is a measure of middle ear and Eustachian tube function. It is not usually considered a measure of hearing but rather it measures the mechanical function of the the middle ear which includes the ear drum and the three ossicles (tiny bones) as well as the ventilating adequecy of the Eustachian tube (for the middle ear to work normally it needs to be filled with air at the same pressure as the outside atmospheric pressure ar any given time including different altitudes).
Other Tests:
Include electrophysiological measurement of the auditory system as well as Central Auditory Processing which tests how auditory information is processed, it tests ‘what the brain does with what it hears’.