Effect of Local Signal Level on Differential Performance in Dichotic Listening
Thomas H. Crystal, Arthur S. House · The Journal of the Acoustical Society of America · 1974
Current studies have used a variety of dichotic listening tasks to demonstrate differential ear advantages in the processing of particular speech elements. The results have been used to draw conclusions about the roles of memory devices, feature processors, signal encodedness, and other factors in speech perception. In the belief that such interpretations are premature, we are conducting a series of experiments to evaluate the influence of the inherent levels of speech sounds on the results obtained from a variety of dichotic listening tasks. In particular, results are reported here for (1) dichotic temporal-order judgments involving three classes of speech sounds, and (2) dichotic discrimination and identification of sound features. The listening difficulty across sound categories was equated by using envelope masking that allowed the specification of local signal-to-noise conditions in the stimuli. In general, the results indicate that knowledge of local signal-level characteristics may be used to explain a variety of results obtained in dichotic listening. The implications of these results for a number of earlier experiments are discussed.