Perceived pitch intervals match log-frequency ratios regardless of register

Evidence

A doubling (or halving) of a value anywhere on a logarithmic frequency scale is equivalent perceptually to a raising (or lowering) by a musical interval of one octave, and multiplying by 3/2 (or by 2/3) is equivalent perceptually to a raising (or lowering) by a musical interval of a perfect fifth and so on. We perceive a given musical interval (octave, perfect fifth, perfect fourth, major third etc.) as being similar no matter where in the frequency range it occurs. For example, a two-note chord a major sixth apart, whether played on two double basses or two flutes, gives a similar perception of the musical interval. In this way, the logarithmic nature of the place analysis mechanism provides a basis for understanding the nature of our perception of musical intervals and of musical pitch. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 821

Categorization

• XREF: Connects to the baseline of my reading on how the basilar membrane’s log place map grounds perception; links to why equal temperament and tuning systems work perceptually.