Why is that important ? If you can really read from a square wave graph what the sound is like, then knowing what device is on the graph should not be necessary.
Anyway, the second square wave sounds the same as the first one, as it was processed with an allpass filter (it has a flat magnitude response, and only changes the phase - by 90 degrees at 60 Hz), but the low frequency delay (a few ms under 100 Hz) is either inaudible or at most it has a minor effect.
The third square wave sounds noticeably different, despite looking more similar, because a 3 kHz lowpass filter was applied.
Edited by stv014 - 2/13/13 at 8:32am