When attending gototraining sessions that I am not an organizer, I have noticed that the connection and audio information is in German (even though my setting is English). Also, the audio does not allow me to unmute although I can hear other presenters.
@LBeekman You should have immediate muting controls available, unless the scheduling Organizer has muted all participants without your knowledge.
Is your local computer's default language also English?
If so, have you already performed a full re-install of the GoToMeeting software?