Our ears and brain have good resolution, but little precision and very poor memory.
I have measured differences in speaker cables, mainly due to poor amp/speaker interaction. Audible? Questionable. That had little to do with cost. Expensive does not mean better. ICs? ... Any measureable difference is not of the audible type. A good IC like a power cable may have some impact noise levels. Changing bass or even treble response as often claimed? ... Bass not at all, and treble not enough to hear a difference.
Most perceived differences disappear when you don't know the change.
I have measured differences in speaker cables, mainly due to poor amp/speaker interaction. Audible? Questionable. That had little to do with cost. Expensive does not mean better. ICs? ... Any measureable difference is not of the audible type. A good IC like a power cable may have some impact noise levels. Changing bass or even treble response as often claimed? ... Bass not at all, and treble not enough to hear a difference.
Most perceived differences disappear when you don't know the change.
Our ears are EXTREMELY precise instruments, that's for sure.