You "
could", but it would take a lot of work, and most likely, programming. And not Voip
Most online radio stations work with a .m3u file (playlist file). Inside that playlist file, there is 1 url linking to a small mp3 file. the mp3 file is 30-ish seconds long, and the next one is uploaded every 30-ish seconds... so the effect on the user end is a streaming station (because the m3u starts over when it reaches the end).
Where the programming would come in is where you hack up all of your audio into 30 second bits (in realtime) and upload them (programatically would be the only way to go). I listen to a radio station that uses 1`file in their m3u file, but sometimes it screws up... so if you
do actually do what I just said, you could use 2 urls in your m3u and alternate with their uploading.
Example of .m3u file (from
http://www.wklu.net/)