[RFI] Sound Card

[Joe]

For my playing of wav files for contesting I am going to dedicate a nice 
small USB type sound card ya know looks like a thumb drive?

Now in thinking of RF issues of RF getting into it. Where would be the 
best placement of it to lessen the possibilities of RF getting into it?

Having it right at the computer, and run the AUDIO cable long enough to 
reach the radio.

OR

Have it right at the radio, and run a USB extension cord to the computer.

What is less prone to have RF Issues?

Joe WB9SBD