Abstract: A special effects system for simulating physical sensations in an audience during the presentation of a motion picture. Relatively high intensity, very low frequency random noise is acoustically coupled to a theater space to produce psychological and physiological sensations, much as earthquake movements, in the audience. The special effects are controlled by a control sub-channel which is either frequency multiplexed onto a conventional optical audio track or, in a magnetic stripe film format, the control sub-channel is placed on an accompanying optical track. The presence and amplitude of two control frequencies in the sub-channel are detected and logically combined, providing four separate digital function control signals and two analog control signals which are variable in amplitude.

Abstract: A special effects system for simulating physical sensations in an audience during the presentation of a motion picture. Relatively high intensity, very low frequency random noise is acoustically coupled to a theater space to produce psychological and physiological sensations, much as earthquake movements, in the audience. The special effects are controlled by a control sub-channel which is either frequency multiplexed onto a conventional optical audio track or, in a magnetic stripe film format, the control sub-channel is placed on an accompanying optical track. The presence and amplitude of two control frequencies in the sub-channel are detected and logically combined, providing four separate digital function control signals and two analog control signals which are variable in amplitude.