Yes, it is... but that "format"...
- spacing counts. Or, if you want to run the possibility of two, yes two (or more) messages in one, you can do the Radio.ini and associated files below that, in the Sound / Radio / Washington / Events folder, and even "broadcast" it, if you can do "voice-over". Of course, I don't think they'd broadcast about Wounded Bear over public radio airwaves... but we just discovered that little trick the other day, quite by accident... Like most other "sounds" though, the game does "re-broadcast" the event upon game re-load after a Save.