Below ~200ms, auditory perception switches into a different mode

At durations shorter than approximately 200 ms, many aspects of auditory perception change character and different modes of hearing come into play. Above this threshold listeners perceive discrete events with pitch, timbre, and temporal sequence in the normal note-like way. Below it, hearing transitions: brief sounds lose stable pitch (timbre takes over), temporal ordering becomes harder to determine, and the ear begins fusing rapid successions into continuous textures. This boundary is not a hard line - the exact threshold depends on frequency content, amplitude, and context - but it defines the region where granular synthesis exploits perceptual fusion and fission.

Examples

A 300ms sine burst is heard as a pitched note. A 10ms sine burst at the same frequency is heard as a click with some pitch color. A rapid stream of 20ms grains at 30/sec fuses into a continuous tone.

Assessment

What changes in how you perceive a sound when its duration drops below about 200ms? Give two concrete examples of perceptual phenomena that only emerge below this threshold.