On the community forums at GameFAQs.com, users are comparing notes regarding their favorite method of listening to game audio.  This includes an interesting poll, wherein users can vote for their preferred video game listening environment.  The winner?  Gaming headsets, which pulled 30% of the vote.  This was followed by 5.1 surround systems, TV speakers, 7.1 surround systems, with an external stereo system trailing the field.

Why does this matter to a game composer?  Our method of monitoring our mixes should reflect what the majority of listeners will experience in-game.  If we primarily hear our mixes through stereo monitors, we’re experiencing the music in a way that matches the listening environment of only a small percentage of our target audience.  We’ll have to make sure that we check our mixes through multiple audio delivery systems, with a particular emphasis on headsets.

Source: GameFAQs