That's because the connection is analog (3.5mm), not digital (usb). There's a lot of noise inside your laptop. On a pc, high end mobos have isolation technologies to minimize electromagnetic interference. Same goes for sound cards, which are essentially amps/dac. What I would suggest is to get an external amp, and that would take all the signal out of your laptop. That would solve your problem. If you don't wanna do it, another suggestion is to return your product and get a replacement for one with a usb plug.