Pitch perception experiments restrict stimuli to a clearly audible frequency range.

Evidence

Patterns were generated by randomly selecting a set of five intervals, with the restrictions that each interval should only occur once within a pattern, and two intervals with same magnitude but opposite sign should not follow each other immediately in the sequence (to prevent the occurrence of repeated tones in the pattern). All tones making up the pitch sequences were harmonic complexes, consisting of the first four harmonics of the nominal pitch, exponentially decreasing in amplitude (1:1/2:1/4:1/8) to give an oboe-like timbre. … The first tone of the first pattern always had a pitch of 450 Hz. To avoid the use of pitches which may not be clearly audible to everyone despite reporting normal hearing, all pitches were restricted to lie between 100 and 3200 Hz. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5294