Vanguard Saga of Heroes doesn't support Voice Chat. Several guilds offer voice chat services through hosted third-party applications.
An Official Forum Post asked existing players what their favorite application for voice chatting was and why.
Third Party ApplicationsEdit
The following are the most commonly used applications. Most offer a push to talk (PTT) functionality that can be accessed from within Vanguard.
Vanguard: Saga of Heroes is also available on Steam. Steam offers communities and voice chat.