Fig. 3.

Stimuli and results for experiment 2 (melody discrimination). (A) Representations of a sample melody in the conditions tested as spectrograms and in musical notation. In each condition, the first four-note melody was always comprised of pure tones. The second melody was comprised of either pure tones or filtered complex tones and was the same as the first or its second or third note was raised or lowered by one step in the diatonic scale. In this example, the second note is lowered by one step. Melody 1 in the pure-tone low condition was drawn from frequencies between 500 Hz and 1 kHz; melody 1 in the pure-tone high condition was drawn from frequencies between 1.5 and 3 kHz. In both conditions, melody 2 was transposed up by two octaves. In the complex-tone high condition, melody 1 consisted of pure tones drawn from 1 to 2 kHz, and melody 2 consisted of complex tones filtered between 7.5 and 16 kHz, with F0s between 1 and 2 kHz. The complex-tone shifted condition was the same, except that the components within each complex tone were shifted up or down by the same random amount to disrupt their harmonic relations while maintaining the same frequency spacing between components. The shift was selected for each complex tone independently from between 10% and 90% of the F0 with uniform distribution. (B) Average percentage of correct responses in the different conditions in Experiment 2 a and b. Performance in the complex-tone high condition (red bars) was good in both experiments, despite the absence of components below 6 kHz, whereas single pure tones above 6 kHz in the pure-tone high condition (dark blue bar) did not convey reliable melodic information. The poor performance in the complex-tone shifted condition (pink bar) from Experiment 2b shows that listeners were not able to reliably perceive melodic pitch using periodic temporal envelope or beating cues. Error bars represent the 95% confidence interval around the mean.