Apart from the price, is there any "real" difference between these two types of copper, in a cable of similar construction used between a source and pre-amp?

I see from the Atlas website that they say this about OCC
The benefits are obvious, with almost no crystal boundaries, the audio signal is no longer impeded down the copper wire and more information and detail is delivered faithfully to the receiving equipment.
How "golden" do your ears have to be to hear the difference?