Most of the time when chatting in-game there's a terrible high-pitched screech before or after someone talks. You can even hear the screech if you hear them tapping in buttons or any noise on their end at all. It's horrible. It usually only happens if someone double taps the chat button to lock in chat but the noise in unbearable and makes talking in-game, one of the biggest parts of DayZ, a challenge because you just don't want to.