Time-varying sound loudness is set by integrated loudness peaks, not moment-to-moment level

Evidence

So far we have reviewed the perception of loudness caused by tone bursts. Speech and music are composed of sounds whose spectrum changes all the time. The perceived loudness can thus be expected to change all the time. However, it has been found that the loudness of such timevarying sounds seems to be the result of a short-time integration of sound power followed by a processing of the peak values by another mechanism. The perceived loudness is thus defined by loudness peak values. For example, a sound, in which 200-ms sound bursts alternate with 200-ms pauses is perceived to have loudness similar to a corresponding continuous sound. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1177

Categorization

• XREF: Connects to soundscape and noise-perception reading — this explains why intermittent sounds like passing aircraft or phone chirps are judged by peak loudness, relevant to the perceptual weighting behind noise annoyance.
• DEFINE: Clarifies how ‘loudness peak’ and short-time integration jointly account for percepts of dynamically changing sounds.