The "Techniques" forum is probably more appropriate.
Here's what I would do though:
Shelve everything below about 800hz and everything above 8000hz.
Boost between 2000 and 6000hz to the point of clipping a tube emulator plugin--not completely overdriven, just enough to make it sound "hot" on transients and sibilance.
Add some white noise or static on another track and sidechain a gate using your vocal track to it so that it only keys when you're talking (in other words, you only hear the static when your voice track is producing sound).
You can add some short delay and amplitude modulation and play with phase if you want it to sound like the signal is dropping in and out (mentioned above).
These are all starting points, you'll have to kind of dial it in to get exactly what you want.