Suprathreshold Bekesy excursion widths in normal and sensorineural impaired listeners.

Abstract

Normal-hearing (N:20) and sensorineural adults (N:15) performed sweep-frequency Bekesy audiometry from .1-8 kc/s at threshold and at MCL and UCL with both continuous (C) and interrupted (I) tones. Excursion width was measured in 1-db steps. Normals exhibited no C-I differences in excursion width at any level, and differences between the two groups of Ss were negligible for I tones, but the sensorineural Ss yielded significantly smaller widths at 3, 4 and 6 kc/s for C tones at both suprathreshold levels. SInce a number of sensorineural Ss did not yield tracings at UCL, it was recommended that MCL be traced as one feature of site-of-lesion testing. Of the sensorineurals, 75% yielded widths of 5 db or less for C tones at MCL, and this criterion in a sweep-frequency Bekesy is suggested as of clinical value.