Hey there, SimonRussi
I've found the best way to get that radio 'sound' is to cut out all sound below about 440Hz and above about 3520Hz.
This is what a real radio does (as it doesn't transmit sound across all frequencies the human ear picks up
).
As far as static is concerned, in most sound editors there is a distortion type effect... I generally play around with that until I get the sound I'm after.
Another method is to record a separate sound file of static (you could probably find some radio static on the net) and merge (mix) it with your speech file.
Hope that helps to point you in the right direction