Excursion size Bekesy tracings of continuous and interrupted tones at threshold and at most comfortable loudness in cochlear-impaired ears.

Bekesy fixed-frequency tracings at .5, 1, and 4 kc/s were obtained at THL and at MCL from 64 men with cochlear-impaired ears. Mean continuous- (C) and interrupted-tone (I) excursion sizes were compared within 4 hearing-level categories from mild to severe/profound. Mean I-tone excursions were comparable at THL and MCL, regardless of amount of loss or frequency, the majority of excursions between 5-15 db. Mean C-tone excursions at MCL were reduced to less than 5.5 db á value at HTL said by Bilger (1965) to be clinically significant in separating normal from pathological cochlear function], i.e., significantly more often than mean C-tone excursions at THL . Inspection of excursion size at MMCL appears to have diagnostic value.