I have blocked Internet radio who use port 80.
You should inspect the port and you can add this commands


regex audio-mpeg "audio/.*"


policy-map type inspect http test_radio
parameters
protocol-violation action drop-connection log
match response header content-type regex audio-mpeg
drop-connection log
match request header user-agent regex _default_windows-media-player-tunnel
drop-connection log


class global-class-test
inspect http test_radio


To help you, use a sniffer and capture radio traffic and see http headers.
It is easy to block streaming from media-player, but for other I check the response header and when I see audio/*   (like audio/*  where * can be mpeg,  x-mpeg,  mpeg3,  and/or x-mepg3 …) I close the connection.

Sorry for my bad english.