Harmonic partials facilitate pitch discrimination in humans: electrophysiological and behavioral evidence

The effect of the spectral tone structure on pre-attentive and attentive pitch discrimination was investigated. The mismatch negativity (MMN) component was recorded from reading subjects to pitch changes of identical magnitude in pure tones with only one sinusoidal frequency component and in spectrally rich tones with two additional harmonic partials. In a separate condition, subjects were asked to indicate detection of pitch change by a button press. The MMN was elicited with a larger amplitude and shorter latency by change in spectrally rich tones than by change in pure tones. Furthermore, the subjects' behavioral responses were more accurate for spectrally rich tones than for sinusoidal tones. Together these data indicate that pre-attentive and attentive pitch discrimination is facilitated with spectrally rich sounds in comparison to pure sinusoidal tones.