Contralateral Masking and Bfiklssy Audiometry in Normal Listeners

The influence of low level contralateral masking on the outcome of Jerger's diagnostic Bekesy procedure was studied in normal listeners. In fixed-frequency recordings at 1000 and 4000 cps, masking of the non-test ear was found to separate the tracings for I (interrupted) and C (continuous tones). At 250 cps no separation occurred and tracings obtained with sweep-frequency technique were always superimposed. As to tracing amplitude, masking caused a statistically significant reduction in both C and I fixed-frequency tracings at 1000 and 4000 cps. At 250 cps, there was no significant change. The presence of a contralateral noise appears to influence the adaptative mechanisms of the test ear, presumably through efferent fibers to the cochlea.