In a new Gamasutra feature, developer and researcher Raymond Usher (Crackdown) determines that horror games benefit most from players hearing audio as they inhabit the game world. In the study, two groups of players -- one with the game's audio muted -- were asked to play a group of three games, including popular horror indie Amnesia: the Dark Descent. Their heart rate and breathing were monitored. "Before starting each game, participants had to be in a resting state," writes Usher. "If participants were not in a relaxed state when they began the game, it would be challenging to determine the effects of gaming on physical responses." "[Amnesia] best demonstrates the affect of audio in games. The audio group obtained significantly higher heart and respiration rates compared to the no-audio group during game play," he writes. "This is more impressive given that in the section of game all participants played through, very little happens. There are no enemies and no fighting -- just exploration -- and the results suggest that audio can yet increase immersion in games." The full feature, which also delves into the puzzle (Osmos) and racing (Flatout: Ultimate Carnage) genres, is live now on Gamasutra.