[Skip to Content]
[Skip to Content Landing]
November 1958

Clinical Observations on Excessive Threshold Adaptation

Author Affiliations

Evanston, III.
From the School of Speech and Department of Otolaryngology, Northwestern University.

AMA Arch Otolaryngol. 1958;68(5):617-623. doi:10.1001/archotol.1958.00730020639010

In 1955, Lierle and Reger1 reported an unusual finding in connection with their extensive studies of threshold tracings obtained with the Békésy-type audiometer. When subjects were asked simply to trace threshold for a fixed frequency over a 20-minute period, they found that the tracings remained relatively constant in two cases of end-organ lesion, but dropped markedly in one patient with a subsequently confirmed eighth-nerve tumor. In other words, in the case of end-organ lesion, the intensity level required to maintain a threshold response did not change appreciably over the 20-minute tracing period. In the case of eighth-nerve lesion, however, the patient rapidly required more and more intensity to keep the tone at threshold. Similar results were subsequently reported by Kos.2

This finding is, of course, exactly opposite to the earlier observations of Dix and Hood.3 According to these investigators, the threshold "adaptation" exemplified by the gradual decline

First Page Preview View Large
First page PDF preview
First page PDF preview