I've done the sine sweeps and sine waves are totally unrevealing. For a simple time domain based test, pink or white noise might reveal gross differences, but I doubt we would learn much from that. As I mentioned in a previous post, the differences probably are (IMHO) a complex collection of parameters that only affect in an audible sense, complex musical waveforms.
These waveforms are often thought of as two dimensional sine waves, but are they not three dimensional pulses within the conductor, pulses of electrons like waves, traveling at the speed of light(186,000 miles per second), and indeed higher frequency pulses riding on top of lower frequency pulses?
Complex, indeed. Would one sine wave at a time be different from multiple (complex) frequencies simultaneously?