We can’t always control sources of stress in our lives, but we change how we react to them. The good news is this: The human body is actually designed to experience and handle stress, which is exactly why our bodies react to it so strongly. With some practice, we have the power to learn to use certain elements of stress to our advantage (for example, the fact that stress keeps us more alert and attentive), while better controlling other negative reactions (like digestion problems or giving in to cravings for unhealthy foods).
Delta is the lowest frequency range of .2Hz - 3Hz, corresponding to dreamless sleep, growth hormone release, healing and ultra deep trance. Effective in reducing migraines, chronic pain and blood pressure. By inducing a predominantly Delta state in the brain while remaining awake, you push your brain to operate in a truly unique state that literally forces greater neural adaptation and cross-connection between the regions of your brain.
Most wisdom traditions have employed methods that allow the subjects' brain waves to slow down such as meditation, [Hindu] kirtan, [Gregorian, Menzuma or Sufi] chanting, Hebrew davening, Native American drum circles and rain chants, Tibetan prayer bowls, and whirling dervishes and African trance dancing. The rhythm of these wisdom tradition technologies actually slows people's brain waves from their normal busy brain frequency we call Beta (13-30 cycles per second or Hz), to Alpha (8-13Hz) -- meditation, Theta (4-8Hz) -- deep relaxation and dreaming, and Delta (.5-4Hz) -- slow wave or dreamless sleep.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement.