The human ear detects half a millisecond delay in sound
I guess that makes sense considering we use the delay of sounds reaching each ear separately to determine the direction sound comes from.Assuming the speed of sound is around 340 m/s, in half a millisecond it travels about 17 cm, which, I would guess, is larger than the average distance between our ears.So, using that rough estimation, I would cautiously extrapolate that we probably detect a delay under 0.5 ms, but I'd be interested to see what "detect" means exactly.