In my system, I readily hear differences between speaker cables, analogue interconnects and even digital interconnects. I have demonstrated these changes in sound to others and they are plain to hear. Naturally, I use those cables that have the least detrimental effect on the sound (all cables are detrimental, but some are more benign to the reproduced sound than others in their effects).

I don't suffer from 'expectation bias' (a term that is often thrown in as a subtle slur by the way, just to deride other points of view). I rely on my ears and judgement, which is very good when it comes to sound quality.