Om-Com was a method of communication that could remotely connect to anything with a speaker-grill. It was used by the Chula.
The Chula warship owned by Jack Harkness had Om-Com capabilities. Chula ambulances were also equipped with nanogenes which could give Om-Com capabilities to soldiers.
Gas mask zombies had the ability of om-comming. (TV: The Empty Child/The Doctor Dances)
Behind the scenes[]
"Om-com" possibly comes from the Latin word "omni" (all), and the English word "communication."