Hemi-Sync

Hemi-Sync is a trademarked brand name for a patented process used to create audio patterns containing binaural beats, which are commercialized in the form of audio CDs. Interstate Industries Inc., created by Hemi-Sync founder Robert Monroe, is the owner of the Hemi-Sync technology.

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 claims to involve using sound waves to entrain brain waves. Monroe has claimed that, listening with headphones, brains respond by producing a third sound (called binaural beats) that encouraged various brainwave activity changes. Binaural beats generally have been widely studied for possible mental health therapies, outside of Monroe’s products.