Hedwig Gockel
Hans Colonius
Graduate College ``Psychoacoustics,'' FB 5, Dept. of Cogn. Psychol., Carl-von-Ossietzky Univ. of Oldenburg, D-26111 Oldenburg, Germany
The ability to identify the frequency of the incremented component in a multitone complex was assessed in two conditions, both using the same 11-tone complexes (fixed frequency, equilog spaced, random phases). All components had equal amplitude, except one of the inner 9, which was incremented. The overall level was randomly varied on each presentation. In condition A the tone complex, with the increment position randomized, was followed by a sinusoid either at the increment frequency or at that of an adjacent component (below or above). In condition B the same complex with flat power spectrum was additionally presented on each trial. The sequence of flat and incremented profile stimuli was randomized over the first two presentation intervals, followed by the sinusoid. In both conditions subjects had to indicate whether the frequency of the incremented component was same or different from that of the sinusoid. Thresholds for these two conditions were estimated by the use of an adaptive procedure and compared to the thresholds of the same subjects in discriminating between the flat and an incremented profile (with signal uncertainty). Results indicate that identification ability is at least as good as discrimination. [Work supported by DFG.]