MUSIC VOLUME: If music be the food of Borderlands 2, play on.
SOUND EFFECTS VOLUME: Adjust volume of gunshots, footsteps, etcetera.
DIALOG VOLUME: Adjust volume of characters when they speak.
SUBTITLES: Toggle whether or not dialog appears in printed text at the bottom of the screen.
PLAYER CALLOUTS: Toggles all quips and callouts by player characters.
PUSH TO TALK: If this is off, you will constantly transmit any sound your microphone picks up. On gives better network performance.
VOIP CHAT VOLUME: Adjust the volume of incoming voice chat.