Athens police, just up the road, uses full-time voice inversion. I have wondered whether the voice inversion sounding stuff on 154.205 is really just bleedover from Athens PD, since the 154.205 repeater gets pounded with interferance. If the repeater gets opened with crud it's possible other crud like Athens can find it's way in. The only time I've heard this is when the 154.205 repeater is getting opened by interferance out of the county.
Otherwise, if Bradley Fire-Rescue is really using voice inversion, it's easy to decode. There are "boxes" or now software out there that will allow you to listen to voice inversion. Don't know if this falls under the "listening to encryption is illegal" category, since voice inversion is kind of like signal sideband used for CB and amateur radio.
But why the fire department needs to scramble or encrypt their traffic is beyond me! In most departments, if there's sensitive information to pass along, firefighters use their Nextels or cellphones.
Interesting to see how this works out for Bradley County Fire!
BG..