Experiment with Pitch and Partials

Using pitchpartials.m:

• add successive equal-amplitude harmonics to f0 = 55 and f0 = 440.
• listen for gradual reinforcement of the pitch frequency.
• listen for a sense of a higher frequency (especially f0 = 55).

Figure 4: Peaks and wiggles.

Regular peaks account for hearing f0, and wiggles creates sensation of a higher pitch.

We can get rid of this sensation by choosing the relative amplitudes differently.

At around 440 Hz, the ear can get the ``right'' pitch from the first 6-12 harmonics but NOT from harmonics 7 through 12.

• at 440, the time resolution of the ear isn't good enough to follow the envelope;
• instead, we get a sound based on the frequencies of all the wiggles, small or large.

Duplex Theory of Pitch says we use two pitch mechanisms:

• based on periodicty at lower frequencies,
• based on frequency (place theory) at higher frequencies.