Why is Dead Space 3 using the webcam?

Whenever I start up Dead Space 3 it starts using my webcam. I have checked all of the settings menus inside of the game as well as Origin (which I am running it through) and cannot find any settings that use either the webcam or its microphone. I am sure that this is the program using the webcam as the "in use" indicator light turns off if I minimize the game.

Where can I find the setting to disable this?

After a bit of digging around it seems like the most likely option is that it is using your webcam for your microphone. There are no in-game options dealing with the microphone and there were pre-release reports that the engine would react to your own screams while playing. The mic is auto-on during co-op and the only mute function in the game relates to other players and is in the pre-game lobbies.

All of this leads me to believe that DS3 is accessing your webcam for its mic functionality and the camera's indicator does not differentiate between the mic/camera exclusively. This can be easily tested if there is a software setting to independently control the mic/camera.

As a caveat, I do not own DS3 nor do I game on PC, this question was just independently interesting and my answer is based purely on computer hardware/software knowledge and digging through the dregs of forum posts.