If you think it's a USB issue, have you tried to see if there is an updated BIOS to the computer or maybe getting a 3rd party USB card to plug into a vacant slot...if you have a vacant slot, that is. I didn't like the default USB speed of one computer I had, so I got a 4 connector USB card and put it in the computer. That solved my problem.
Also, not all USB plugs are the same. Sometimes the ones in the back of the computer are hotter than the ones in the front. It's not always the case, but sometimes it is. I've received notices on my desktop that I should connect something to a faster port than the one I have it connected to, when I use the front USB jacks. All of this is just food for thought.
I guess you've also canceled out updating the driver to the interface. The noises don't sound like a bad or weak connection, but maybe a defective driver? It does sound strange that the interface would be humming at all, though. That sounds more like a power issue with it. There shouldn't be any humming at all.