Minimum system requirements for Dark Souls: Prepare to Die Edition released earlier suggested the PC release would utilise a microphone during multiplayer. Namco has said the listing was in error, as the game does not support in-game voice chat.
The inclusion of a microphone would have run counter to From Software's past approach to multiplayer in both Demon's Souls and the console version of Dark Souls; both games failed to include voice support and the developer discouraged planned encounters with friends.
That said, Dark Souls' use of covenants helped like-minded players find co-operative buddies, and improved matchmaking was promised for the PC version.
Dark Souls: Prepare to Die Edition launches on PC in late August, and includes new content which will release as DLC for the PlayStation 3 and Xbox 360 versions.