A microphone is mounted next to the joystick in the joystick holder and the user speaks directly into it. The microphone is used either as input for voice control or together with Ventrilo to be able to communicate with other players. Ventrilo is a free program that makes it easy to talk to people online. All you need is a microphone and an internet connection. Gamers use Ventrilo, which is best for fast online games.
For example Clas Ohlson, clasohlson.com/uk/ (last checked March 2020)