Multi-Gaming Community

Mumble Voice Communications

Mumble is a free, open-source, cross-platform voice over IP application.

Its primary users are gamers, and it is similar to programs such as TeamSpeak and Ventrilo. It uses a client-server architecture where users who want to talk connect to the same server.

You can download it from the official Mumble page. Once installed, you can connect to the Specialattack server with the following details:
Username/PasswordSame as in the forums 

Before utilizing the program, it is strongly recommended to go through the Audio Wizard.