Saw Alive is a horror maze at the Thorpe Park theme park in London, England. When people go into the maze, it is very dark. There are live actors who pretend to attack them, and sets themed to look like torture scenes from the Saw films, complete with moving machinery, and a real electric fence.
In this event, we took groups of four people, and split them into two pairs. Two people were kitted up with breathing sensing gas masks, microphones, and also infrared torches with a small infrared camera attached to them. The torch camera meant that people could film what was going on, but could not see any better than a normal participant. We used a small netbook in a bag to transmit audio, video and breathing data back to a base room, where the other pair were watching the breathing traces and video, and listening to the screams of the people in the maze.
People who were second through the maze had already heard the screams of their friends in the maze, whilst not really being able to see masses of detail about what was happening to them. This really seemed to pump them up and make the experience seem more scary.