Abstract
Results are reported in a series of 125 perceptively impaired ears by determining the course of threshold tracings during a 3-min stimulation, first in quiet and then in the presence of 83 db (over-all) white noise. Larger than 10 db threshold shifts occurred in 21 ears in quiet (17 per cent) and in 44 ears in the presence of noise (35 per cent). Abnormal fatigability may appear in all categories of perceptive hearing loss and as such is not pathognomonic to any particular locus localization of the lesion.