Pulsed, percussive sounds like drumming will also produce the frequency following response. While most light and sound machines only use percussive sounds, all the Mind Gear systems also produce binaural signal sounds (explained below) synchronized with the pulsing lights.
Binaural signal sounds produced by our light and sound systems create a resonance effect that synchronizes the two hemispheres of the brain. Feeding one tone to the right ear and a slightly different tone to the left ear produces a beat frequency in the brain. Because the process requires the cooperation of both brain hemispheres, a unique mental balance results. With the beat frequency adjusted to the alpha or theta range, most people can feel a gentle entraining effect. This frequency following response (entrainment) forms the foundation for many of the effects of mind machines. Our L/S systems use both pulsed and binaural signal sounds. The BioTones Software acts as a PsychoAcoustic Sound Generator on a PC with a sound card.