Audio headsets work by decoding the surround recording into its discrete channels. Once this is done, the audio can be heard in its 4-channel or 5.1-channel surround format. This produces the surround sound effect.
With 3-D audio headsets, sound gets distributed to the front and the sides of the head instead of just to the right and left. Since the sound waves are altered by these headsets in this manner, the ears perceive the sound as if it was coming from several directions.
Modern 3-D movies are projected at 48 frames per second, which is twice the number of images per second of a non-3-D film. One 24fps image is intended for each eye. Glasses using LCD panels alternatively hide one eye and then the other, synchronized with the movie.