The jnd or "just noticeable difference" is the smallest detectable difference between the levels of two successive sensory stimuli. Of interest to tuning theorists and microtonal musicians is the jnd for pitch, which varies over the frequency range of the pitch-continuum.
The number of perceptible steps in the audible range of human hearing, about 16 Hz to 16 kHz, is about 1400, which very roughly approximates to 140-edo.
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