PRESBYACUSIS .I. COMPARISON OF MANUAL AND AUTOMATIC THRESHOLDS

Threshold determinations employing manual and automatic audiometry were made in one experienced and one inexperienced normal control group and in two groups of presbyacusis, one of which showed signs of acoustic trauma. The manual and automatic tracings were superimposed in the experienced normal group, while in the other three groups the manual method resulted in poorer thresholds. Continuous and pulsed tone tracings were overlapping in the normal groups but in old age the pulsed tone tracing was clearly better than the steady tone threshold. The threshold amplitudes were significantly larger in presbyacusis than in normal subjects; the low tones in all groups showed larger amplitudes than the middle or high frequencies. Advancing age did not decrease the performance in Békésy audiometry, and the best thresholds were obtained by the automatic pulsed technique. This study was supported by a grant from the National Research Council for Medical Sciences. © 1969 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.