Dichotic vs monotic masking functions may reveal central organization for speech identification
Charles I. Berlín, Harriet L. Berlin, Larry F. Hughes, Phillip Dermody · The Journal of the Acoustical Society of America · 1976
Previous studies of dichotic interference of speech by nonspeech challenges have presented targets and challenges at equal intensities In this study targets (CV stops) were first paired monotically with challenges (noise, vowel, sweeps, bleats and CV's) with the target held constant at 70 dB SPL and the challenges varied in intensity. Masking functions of the challenges on the targets were then generated. The dichotic presentations of the challenges vs the targets were then arranged at two levels: (1) that point at which the challenge masked the target to between 62% and 65% and (2) that point at which the challenge masked the target completely (less than chance). Using these monotic masking functions as references we asked subjects to listen only for the targets presented to one ear while the challenges were presented to the other ear. Dichotic interference functions revealed that, despite uniform monotic masking capabilities, the challenges were quite different in their dichotic effects. Bleats and CV's generated the greatest interference dichotically; sweeps generated some interference but, in contrast to bleats and CV's, did not generate a right ear advantage. The implication of these results will be discussed with respect to central organization for speech detection. [Support by NS-11647.]