Why Missing Fundamental Stimuli are Counterintuitive

The fact that tone complexes with missing fundamentals can be perceived to have a pitch that is below their lowest frequency component can have counterintuitive consequences.

Consider the tone sequence shown in the spectrogram here:

 

 

A pure tone 700 Hz pure tone (labelled "A") alternates with a tone complex containing frequencies 800, 1200, 1600 and 2000 Hz (labelled "B"). All frequencies in B are above the frequencies in A, but nevertheless when you listen to these stimuli you will find that B sounds lower because the pitch of B is perceived to be that of a missing 400 Hz fundamental.


 

 

Or here is another example:

spectrogram

The sounds in this spectrogram are harmonic complexes with a fundamental frequency that rises from 110 to 220 Hz in semitone steps. So the pitch should be rising from the musical notes A2 to A3. But the harmonic complexes have been bandpass filtered to be 3.5 octaves wide with the lower edge of their passband falling from 880 Hz to 440 Hz. So the frequency components become increasingly lower, but the pitch should get higher, at least in as far as harmonic structure is the dominant pitch cue. Do the pitches sound falling or rising to you?


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