Going by Amirs testing, a short cable will measure better than a longer one.
With most cables, digital as well as analog, he found no real difference between cheap (don't go super cheap, but decent quality) and super expensive.
One flat and fairly expensive USB cable measured better than a normal one (wich might be due to separation of data and power).
Overall, as long as the plugs fit properly and tere are no defects (as said, don't go super cheap), I really doubt you'd be able to hear any differences, even if you might be able to measure small ones.
With headphone cables in particular, impedance/resistance can make a real difference since that needs to be added to the output resistance of the amp.
Given a low impedance driver (say 20 Ohms) a very high resistance cable (say 3 Ohms) combined with the output resistance of the amp (say 1 Ohm) can change tonality. Most decent headphone cables have a low resistance (in typical length <0,3 Ohm), however there are super expensive and super cheap ones that - more or less on purpose - do not. With high impedance headphones like the 300 Ohm Sennheiser, even a very high resistance cable liekly wouldn't make an audible difference.
To sum it up: Good cables will sound the same (not at all you could say) and don't need to cost more than a couple $.