Re: for dogs only
Apparently, it is. Back when i were moving faders for a living, I had the opportunity for a chat with a bloke from Klark Technik (they make rather good graphic equalisers, amongst other things) and while most of the conversation disappeared some way over my head, he made the point that they engineered their kit to take account of harmonics outside the threshold of human hearing simply because it seemed to make a difference. These weren't mental 'put your speakers inside a pyramid' audiophiles, these were people building robust kit that was going to be put into flight racks and sent around the world.
Something, something psychoacoustics, if I recall correctly.