Loudness constancy occurs regardless of whether sound is speech or noise

Evidence

Taking these small and inconsistent effects together, we found no evidence that binaural loudness constancy is greater for more ecologically valid stimuli such as connected speech. Indeed, for both speech and noise, occlusion of the ear led to little reduction in loudness (a small summation effect), suggesting that loudness constancy occurs independently of stimulus type. It should be noted, however, that quite prominent reverberation was present in our experiment, which reliably cued the existence of an external sound source. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1525

Categorization

• QUESTION: Reverberation cuing an external source may be the key manipulation, not ecological validity of the stimulus itself.