Cancelling both ears’ HRTFs requires a fixed speaker layout and a motionless head.

Evidence

To convert binaural signals into a form suitable for normal stereo presentation, it is necessary to cancel out the HRTFs associated with the positions of left and right speakers, as shown in Figure 7.16. This involves using two filters that are the inverse of the HRTF to each ear and two other filters that model the cross-coupling between the two ears and subtract the effect. Clearly this is only going to be possible for a particular speaker layout and a forward-facing listener with no head movement. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2255

Categorization

• DEFINE: HRTF is the head-related transfer function — the per-ear filtering the head and pinnae impose on incoming sound, which is the engine behind every spatial-audio illusion.