Latency in human speech transmision has deep psychological impact on a conversation. A Japanese research project called SpeechJammer exploited this part of our senses by inventing a “shut up gun.” When pointed at a person it makes them immediately stop talking. Everyone who has used a cell phone knows the frustration of “echo” where you hear your own voice, slightly delayed. The delay is caused by the network latency of the cellular carrier.
Here in the USA, some prowords evolved into a coloquial language, complete with slang thanks to the Citizen Band radio boom of the 1960s and the truck driving culture that used it to communicate while on the road. The 1977 film Smokey and the Bandit is more than just a touching love story with world class actors, it is an amazing dramatization of an information culture that resembled pre-Internet BBS systems and current day Internet Relay Chat (IRC) networks around the globe. The truck drivers portrayed in that movie have a mobile, decentralized information sharing network that is anonymous. The users have pseudonyms and a language of their own. Many of them have never met their CB radio friends IRL. They are invisible companions on the lonely road of the US of A.
Old ideas are worth bringing back if they have strong roots. CB and general purpose radio telephones have a long history, unlike the standard the standard of tody, VoIP. Perhaps these features are thought of as obsolete or not cutting-edge enough to model into a digital system. Regardless of the reason, if you are looking for a mobile and open source PTT solution to use on the Internet with anonymity and security, Mumble over Tor is currently the state of the art. All you have to do is throw in some prowords to keep the conversation flowing.