Head movement resolves directional ambiguity and explains headphone sounds seeming internal

Evidence

Head movements have long been assumed to be important to satisfactory externalization in binaural headphone reproduction (Toole, 1970). The brain protests when the musicians and the performance venue move with the head. But mismatched HRTFs are a logical contributing factor to the perceptual error. — Toole, Floyd E, Sound reproduction- the acoustics and…, 290

Categorization

• QUESTION: Toole cites his own 1970 work here; worth chasing whether later research quantified exactly how much head-tracking compensation improves externalization ratings.
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 290
• XREF: connects to: Head-motion-dependent sound changes are required for external sound localization; Head symmetry creates a cone of directions where sound localization is ambiguous; Lack of head-tracking dynamic cues causes headphone audio to sound internalized (+13 more)

Broader Connections

• Static binaural images sound inside the head until head movement is tracked #corroborates (0.95)
• Headphone listening reveals sounds ordinarily outside awareness #expands (0.75) — Pauline Oliveros, Deep Listening, 279