Sensurround

Sensurround is an audio technique developed in the 1970s for the presentation of theatrical movies. According to Halliwell's Film Companion, the process involved "the augmentation of violent action on screen by intense waves of high decibel sound, enough, in some documented cases, to crack ribs." Originally developed for the Universal production Earthquake, the process was used used in two subsequent films, Rollercoaster and Midway.

A Loud Reception

Sensurround involved the installation of special very large woofer speakers which were placed in the corners of the theatre and triggered by a special secondary pickup on the optical soundtrack. The speakers could only play a single rumble noise during the various moments in the film when tremors were experienced onscreen.

Sensurround never caught on due to disturbances at the local cineplex. When Earthquake opened in December of 1974, Godfather II opened the same week and often played in the next theatre auditorium. Theatre managers were inundated with complaints from audience members, literally shaken, by the bleeding of Sensurround into their theatre exhibiting Godfather II. This disruption was not worth the effort for most theatre owners.

The rumble effects from these speakers also caused strucutural damage to some cinemas. When Earthquake first showed in one cinema, the ceiling started to crack and pieces of plaster fell off. The cinema had to suspend a net above the seats to stop pieces of plaster falling on the audience.

Trivia

The alternative pop/rock band They Might Be Giants have a song called "Sensurround" which appeared on the soundtrack to the first Mighty Morphin Power Rangers movie and one of the band's EPs. Many fans consider "Sensurround" to be one of the band's best songs. The song makes several references to the theatrical audio technique.