Out-of-phase binaural tones can double perceived loudness

Evidence

The dat.a of the two figures indicate that phase differences in binaural hearing can influence loudness, so that out-of-phase presentation of tones increases loudness up to a factor of two (equivalent in effect to a lO-dB level difference for monaural presentation). Phase changes in both signals and maskers (noise, in this case) clearly influence binaural loudness. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1738

In summary, under favorable conditions binaural loudness may achieve almost twice the value of monaural loudness for the same physical level presented at about the same time. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1740

Categorization

• XREF: Connects to interaural phase/timing processing and binaural unmasking phenomena in hearing science.
• corroborated: 3 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1738; Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1740