Pitch-induced illusory percepts of time.

Past research suggests that pitch height can influence the perceived tempo of speech and music, such that higher-pitched signals seem faster than lower-pitched ones. However, previous studies have analyzed perceived tempo across a relatively limited range of fundamental frequencies. To investigate whether this higher-equals-faster illusion generalizes across the wider range of human hearing, we conducted a series of five experiments. We asked participants to compare the tempo of repeating tones from six different octaves and with 15 different interonset intervals to a metronomic standard tempo. In Experiments 1-3, we observed an inverted U-shaped effect of pitch on perceived tempo, with the perceived tempo of piano tones peaking between A4 (440 Hz) and A5 (880 Hz) and decreasing at lower and higher frequencies. This bias was consistent across base tempos and was only slightly attenuated by synchronous tapping with the repeating tones. Experiment 4 tested synthetic complex tones to verify that this nonlinearity generalizes beyond the piano timbre and that it was not related to the presence of low-frequency mechanical noise present in our piano tones. Experiment 5 revealed that the decrease in perceived tempo at extremely high octaves can be abolished by exposing participants to only high-pitched tones. Together, our results suggest that perceived tempo depends more on the relative pitch within a context than on absolute pitch and that tempo biases may invert or taper off beyond a two-octave range. We relate this context-dependence to human vocal ranges and propose that illusory tempo effects are strongest within pitch ranges consistent with human vocalization.