Affinity
2.0
Additional Information Page 53
1.7.16 Tone Decay
17
This is a test to help identify the adaptation of the auditory system (Carhart, 1957). It involves measuring the
perceptual reduction in a continuous tone over time. This can indicate towards a cochlear or neural cause of
deafness.
The test involves looking at the patient’s response to the onset of a supra-threshold sound and then their
continuous response to this as it continues over time. For example, in Meniere’s disease this is detected
correctly on onset but rapidly deteriorates due to dysfunctional hair cells (Carhart, 1957). A normal response
should be maintained for a minute of stimulation, should a patient not be able to maintain this then the
stimulus intensity is increased until a minute is achieved. This is only increased up to a maximum 30 dB
supra-threshold.
Previously this test could only be administered manually with the Affinity
2.0
/Equinox
2.0
Suite and a stopwatch
but now we have added this test to the software for ease of use.
Required Items:
• The Affinity
2.0
hardware
• Licensed AC440 Audiometry module within your Affinity
2.0
hardware
• Calibrated Headphones or insert phones
Test Procedure
1. The patient’s Audiometry is obtained.
2. The patient is then instructed to continuously respond to the tone if they hear it and not respond as the
signal fades/is absent.
3. The test is administered with a pure tone 5 dB below the subject’s established threshold and then
ascended in 5 dB steps without interruption until the subject responds. As soon as the subject
responds, the system will begin timing (this is shown in the image below). If the tone is heard for a full
one minute then the test is stopped.
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Tone decay requires an additional license
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