Recently, we’ve seen some buzz about Dolby Atmos, a relatively new movie theater sound technology that gives the illusion that there are an infinite number of audio speakers and channels surrounding the audience. It’s hard to believe we didn’t even have wide-spread Dolby Stereo in movies until Star Wars, and if theaters wanted to play Lucas’s space opera, they had to redo their sound system, or Fox wouldn’t give them the film reels.
Several years prior to Dolby Stereo, studios also experimented with a short-lived experiment in movie sound that’s fun to look back on today: Sensurround. It was a gimmick of its time, because the era of the all-star disaster film was in full swing, and while Sensurround wasn’t as high tech as Lucasfilm's THX or Dolby's Atmos, it did try to make movies feel bigger and more realistic through the sheer power of sound, and perhaps helped pave the way for today’s cinema audio technology.
Sensurround was the brainchild of the late Jennings Lang, a Hollywood producer who knew the power of showmanship. Lang was one of the first to call a film an “event” back in 1974 for Earthquake, and legend has it the idea for the film was based on a true event. Lang was in a movie theater when a real life earthquake happened. Then Lang got the idea about making a disaster film where an earthshaker hits L.A., and it would somehow shake the hell out of the audience as well.
“My dad was one of the last true showmen,” says his son, Rocky Lang. “He realized that movies had to be bigger and more event oriented. He was always trying to find a way to make the movie going experience bigger and better.”
"ATTENTION! This motion picture will be shown in the startling new multi-dimension of Sensurround. Please be aware that you will feel as well as see and hear realistic effects such as might be experienced in an actual earthquake. The management assumes no responsibility for the physical or emotional reactions of the individual viewer."- Theater Notice For Earthquake (1974)
By setting up a series of speakers in the theater, and running a soundtrack with very low tones, an earthquake simulation could be done, and there were cues on the Earthquake soundtrack when the special speakers were to be triggered.