Effects of simulated conductive hearing loss on dichotic listening performance for digits

This experiment assessed conditions under which simulated conductive hearing loss would affect performance on a digit dichotic test. Losses were simulated by insertion of EAR plugs, and each subject served as his/her own control. Performance for left ear plugged and right ear plugged conditions was compared with performance in a normal hearing condition (neither ear plugged). Conductive losses did not affect dichotic performance at test intensities 12 dB above the "knees" of monotic performance-intensity functions for the plugged ears (95% correct points) but did affect dichotic performance for some listeners at intensities that were within 8 dB of the monotic knees.