Hemi-Sync was developed by Robert A. Monroe, a radio broadcasting executive and consciousness researcher. He began experimenting with sound patterns in the 1950s, leading to the creation of this audio-guidance technology in the 1970s. Monroe founded The Monroe Institute to further explore and promote Hemi-Sync, which uses binaural beats to induce hemispheric synchronization for enhanced mental states.
Even the CIA was investigating it, but to me that is not really relevant. I tried the first few tapes, and it basically is playing two slightly different tones in each of your ears, which results in a low frequency inteference pattern being audible, and starting to synchronize your brain hemispheres. at least that is what the project claims to do. It might work or it might not, but personally I have not been so interested in reaching an out-of-body state that I never completed the whole set of types.
But one thought occurred to me the other day: where some people complain about ringing in their ears, and call it tinitus, others claim the high-pitched noises are downloads that raise their consciousness. I'd rather believe the latter than the former, but lately the riniging in my ears is no longer a steady tone. Instead it has a low frequency modulation that very much reminds me of the hemi-sync difference frequency. But it does not feel like a sound wave, much more like a product of two radio waves. What if our brainwaves (which are electro-magnetic in nature) are interfering with all the radio waves our ubiquitous technology is emitting all around us? Are we somehow syncing up with the global "mind of the machine"?