FIG. 4.

Results of the PDI experiment (Exp.II). Performance, d', for discrimination of the residue pitch of a complex Huggins Pitch (CHP) which was either presented alone (condition “None”) or simultaneously with another complex tone (interferer) whose F0 was either centered between the F0 of the target sounds in the two intervals, or increased by 40% (condition Dio_PS). When the interferer was shifted in pitch, it was presented diotically. When the interferer was unshifted in pitch, it was presented either monaurally to the same side to which the CHP was lateralized (condition “Ipsi”) or monaurally and to the opposite side of the CHP (condition “Contra”) or diotically (condition “Diotic”). Figures 1(a)-1(e) show, for each subject separately, the mean d', averaged across blocks of 100 trials for the conditions with interferer and averaged across blocks of 50 trials in the absence of an interferer, together with the corresponding standard errors, calculated across blocks. Also indicated in the top left corner is the lateralization of the tonal percept in the CHP complex for each subject; (45 deg.) indicates that, for this subject, the lateralization was half way to the side. Figure 1(f) shows the mean d' across all five subjects and the standard errors across subjects.