INTERPRETATION OF TONE DECAY RESULTS:
Tone decay is usually classified as noraml if decay is 0 to 5 dB , as mild if decay is 10 to 15 dB , as moderate if decay is 20 to 25 dB , and severe if decay is 30dB or above .
severe decay is considered to be suggestive of Retrocochlear lesion and warrants further investigation.
Normal hearing individuals and patients with conductive deafness typically have 10dB or less of tone decay.
patients with cochlear lesion usually have less than 10dB decay but sometimes show 20 dB decay even upto 20dB.
A decay with 30dB should not be considered as a foolproof evidence of retrochochlear pathology, but yhe suspicion that some retrocochlear lesion probably exist . and then the patient go through the detailed neuro- logical examination including Acoustic reflex, Decay test, Brain Stem Evoked Response Audiometery and C.T Scan .The patient should be made to undergo the full audiological test battery.
