7 Hz has long been shrouded in mystery and unease. It sits at the median of the brain's alpha rhythm frequencies and coincides with the resonant frequency of several of the body's internal organs. At high volumes, infrasound at this frequency has been documented to cause disorientation, anxiety, panic, nausea, and in extreme cases, serious physical harm.

The effects of 7 Hz infrasound on the human body have been studied by military and scientific researchers for decades. At dangerous volume levels, it can directly affect the central nervous system, causing bowel spasms, visual disturbance, and a profound sense of unease. This has led some researchers to speculate that natural sources of 7 Hz infrasound — wind, geological activity, certain building resonances — may be responsible for some reports of haunted locations.

At the safe, low volumes delivered by this binaural beat generator, 7 Hz is simply a theta brainwave frequency near the theta-alpha boundary. The binaural beat uses a 170 Hz carrier (left: 166.5 Hz, right: 173.5 Hz). At listening volumes, it is a meditation and relaxation tool — the dangerous effects described above require extreme sound pressure levels far beyond what headphones can produce.