The 'Options' window ( illustration) lets you configure new connection defaults for Voice Chat connection mode.
Voice chat defaults window
You can configure the following options:
Specifies a nickname for chat sessions.
Specifies default user information for chat that others can view via the 'Get user info' command.
Lower values (slider to the left) will result in a low network load, but poor voice quality. Higher values (slider to the right) improve voice quality, but utilize more network resources.