Jack or analogue cinch cables already provide the amplified sound signal. Via USB, so-called frames or data packets are transferred from the hard disk to the USB sound card and then converted and amplified in the speaker.
Washing Machine
More advancements were made to washing machine technology in the form of the rotative drum design. These early design patents consisted of a drum washer that was hand-cranked to make the wooden drums rotate. While the technology was simple enough, it was a milestone in the history of washing machines, as it introduced the idea of "powered" washing drums.
Bose
Basics USB Plug-n-Play Computer Speakers for PC
€109.97