It’s an interesting read. Across the board, with very different types of game, players experienced heightened breathing and heart rates when playing games WITH audio present.
There’s a brief excerpt from the piece below. You can find the whole article on GamaSutra…
[What effect does in-game audio have on players? Audio expert Raymond Usher (Grand Theft Auto: Vice City, Crackdown) shares the results of a study in which players were monitored while playing three games — Osmos, FlatOut, and Amnesia — with audio and without.]
This study investigated the importance of audio in computer games. To do this an experiment was designed that compared groups of participants that played the same games with and without audio. Participants’ physical responses to the games were recorded via a bioharness that recorded participant’s breathing wave, heart rate, respiration rate and skin temperature.
Analysis of the heart rate and respiration rate of participants showed that those playing games with audio had a higher level of arousal (a combination of heart rate and respiration rate) and demonstrated the immersion capabilities of audio in games.
Which is why Euphonious started the off-the-shelf AudioSkins service, which provides smaller projects and indie developers with access to complete audio ‘packs’ for their online / casual / social or mobile games titles…
If you’re a developer, you owe it to yourself to check it out.