How can an INCREASE of delay cause a reversal of apparent sound direction?

Question

How can an INCREASE of delay cause a reversal of apparent sound direction? Would this happen with real signals? Why?

Answer 1

By changing the relative phasing of the signal.

Your ears are very sensitive to the phasing of sound waves. This is one of the ways that humans perceive audio source position and distance. By providing delay, various effects can be generated from multiple speakers that "trick" the ear into believing that the sound source is somewhere it is not. By shifting the phase of a sound, the apparent source of the sound is moved 1/2 a wave length. This is part of how a "stereo expander" circuit works.

If the phasing is done dependent on frequency - very interesting effects can be generated in stereo.