SO i think i know why my companion may have dissapeared, but anyways. Yea my companion Veronica has dissapeared, but i can still hear what shes saying.
Wtf? I think it is because i entered Lucky 38 with her to the penthouse level but ever since then NO Veronica. : ( So i suggest you DONT enter the penthouse level of Lucky 38 with youur COMPANION.

- DarkSunHalifax

My Bad, Your companion can be found in the presidential sweet of the Lucky 38, as for the continuous voice outside in the wasteland, i honestly dont know what that was about but thats what led me to believe it was a bug.