Delays under 100 ms are heard as timbre change rather than distinct echo

Evidence

The sensation of a distinct echo begins around a 0.1 s (100 ms) delay and longer. However, if a tone were played for many seconds, the echo would no longer be perceived as distinct. If a monaural recording is made under these circumstances at a single point and played back, a listener would perceive the tone as affected by the enhancement and suppression combs, spaced by 10 Hz. — Eric J. Heller, Why You Hear What You Hear- An…, 2551

Categorization

• QUESTION: Worth chasing: the threshold at which onset/offset gating determines whether a delay reads as echo vs. comb-filtered tone connects to the perception/physiology boundary.