Yeah I'm thinking the relative phasing of the group delay is essentially having a comb filter effect on the audio, and the difference is perceived qualitatively

Yeah I'm thinking the relative phasing of the group delay is essentially having a comb filter effect on the audio, and the difference is perceived qualitatively rather than anything approximating a time delay. For anyone not familiar, here's an example of comb filtering, where reflections interfere and you get wobbles in your frequency response (shown in an fft mid video). https://www.youtube.com/watch?v=Amj4UevyRfU https://www.youtube.com/watch?v=Amj4UevyRfU