Hemi-Sync is short for Hemispheric Synchronization, also known as brainwave synchronization. Monroe claimed that the technique synchronizes the two hemispheres of one’s brain, thereby creating a ‘frequency-following response’ designed to evoke certain effects. Hemi-Sync has been used for many purposes, including relaxation and sleep induction, learning and memory aids, helping those with physical and mental difficulties, and reaching altered states of consciousness through the use of sound. The technique involves using sound waves to entrain brain waves. created by Hemi-Sync founder Robert Monroe, is the owner of the Hemi-Sync technology.