USB is a data connection. You can certainly send audio encoded as data across a USB connection -- there are a fair number of audio devices which connect that way, from simple I/O (I use an M-Audio Transit rather than my PC's built-in audio hardware, since it's higher quality) up to professional-quality multichannel interfaces. But that requires having drivers in the PC which recognize this external audio device and communicate with it, and computing power in the device to handle the USB protocols and move data between that and D-to-A or A-to-D hardware to play or record (respectively).I believe there are USB-attached video devices as well. The same answer applies: the device has to essentially be a small computer which has video capture or display hardware and which can communicate on USB, and the host PC needs to have a driver which presents those capabilities to the operating system in a form it knows how to work with.So the answer to your question is "no, you can't _convert_ USB to audio or video. But given appropriate hardware and software, you can convert audio or video to digital data and back, and once that's done USB can be used to transport it. between processors.