When two different tones, separated in frequency by only a few Hertz, are introduced — one in each ear — the brain perceives a third, unique tone. Binaural beats work by creating this phantom frequency, which the brain then mimics. For example, if we play a 220 Hz carrier tone into the left ear and a 226.5 Hz carrier tone into the right ear, your brain perceives the difference between the two, which is a subtle beat frequency of 6.5 Hz, the same frequency associated with deep, meditative states. Your brain naturally follows this frequency, and you experience this deeply relaxed state.