Stereo directionality was long mistaken for a pure intensity effect

Evidence

Superficially this would only provide intensity cues to give the illusion of direction to sound coming from two speakers due to the head shading above 1kHz, as discussed in Section 2.6.2. However, this would be incorrect, as demonstrated by Blumlein in 1931. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2195

Categorization

• SEED: An article angle on how the intuitive-but-wrong explanation of stereo (intensity only) persisted until Blumlein’s 1931 demonstration corrected it.