Loudness constancy persists in controlled direct-comparison matching tasks.

Evidence

Experiment 1 demonstrated for the first time that binaural loudness constancy can be observed in a loudness matching task using direct comparisons of loudness between an occluded and unoccluded second ear. Experiment 2 showed that this effect could be partially mediated by the residual sound at the occluded ear, but the remaining effect would seem attributable to the listeners’ awareness of the occlusion. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1525