The gimmick: Sensurround is just a fancy term for making the sound loud. Really, really loud. Used during the 1974 movie Earthquake, large speakers emitted high-decibel rumblings every time the earth shook on screen.
The result: Earthquake actually won an Academy Award for its sound, but the technology was short-lived. Sensurround made things so loud that in several cases, cracks opened in the ceiling of a theater or plaster fell on filmgoers. In the end, theater owners decided the effect wasn’t worth it, though it was used in three more films after Earthquake.