Listeners perceive the pitch of a bass note even when its fundamental is absent.

Evidence

In timbre, an example is the “missing fundamental” bass phenomenon. If the harmonics of a bass note are present, but the fundamental frequency is missing, we are likely to perceive the pitch as that of the missing fundamental. The physically engaging bass energy is missing, but the melodic information is preserved. This is an obvious benefit to small loudspeakers. — Toole, Floyd E, Sound reproduction- the acoustics and…, 316

Categorization

• DEFINE: Defines the missing-fundamental phenomenon, a classic psychoacoustic case of the brain reconstructing pitch from harmonics.
• ADDENDUM: Directly supports the ‘Grafting & Growth’ article’s theme of small physical structures achieving outsized perceptual results, though that article is about trees — the transfer is that limitations can be compensated by perceptual mechanisms rather than raw physics.
• XREF: connects to: The kettledrum outputs a missing-harmonic series yet still conveys a clear pitch — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1306