[kurthr]

Yes, our ears hear power not amplitude so phase isn't so important... except maybe for strange mixing products and reflections off of walls? OK the Audiophiles can hear some of that, but generally it's true if you're listening through headphones.

[marcan_42]

We do hear relative phase relationships at any given frequency between both ears. So if you phase shift one side of a stereo signal and not the other, then yes, that is very audible.

But nodes and mixing products are independent of overall phase across the power spectrum, in a linear system. So if you apply the same phase change to both left and right, the distribution of nodes in the room won't change. The only time these inter-frequency phase relationships start to matter is when you introduce nonlinearities, like distortion.

[kurthr]

Yes, directional hearing is quite sensitive to phase, but there are often multi-reflections inside the outer ear that allow some people to hear phase discontinuities in mono.

[marcan_42]

Anyone can hear phase discontinuities because any phase discontinuity is just a burst of high frequency content.

But typical reflections off of surfaces are largely linear as far as I know, and any linear operation will not introduce any power spectrum changes that are phase dependent. As far as I know, the the ear canal can be largely modeled as a linear system (to within the thresholds of hearability).

The only way to hear phase is to introduce a nonlinearity. That then generates harmonics (or sometimes even lower frequencies), and their power spectrum depends on the specific phase relationships of the incoming signal.

A physical example of a nonlinearity would be a vibrating surface that hits another surface at a certain excursion. Depending on the relative phases of the excitation signal, you can have different peak excursion, and therefore clearly get a different result if one phase set makes it reach the other surface and another one doesn't.