There are 'good connectors' and there are always better connectors. I will not argue this particular case because I have no idea, but usually differences in power cords are quite audible, sometimes big time audible.
Another point - we do not have equal hearing abilities in all components of these complex perceptions. What is imagination to some can be a reality to others. To put it another way - if you don't hear something, that doesn't mean it cannot be heard. How important is the difference? It varies and it depends.