With digital upgrades, Berger’s machine is still in use today, known as an electroencephalography machine, or EEG. Berger used his machine to study the brains of psychologically normal and abnormal people and discovered the first brainwave, called the alpha wave and also known as the Berger wave, along with the faster beta wave, which he observed suppressing the alpha wave when subjects opened their closed eyes.
Binaural beats is a method where two sound waves of different frequencies are introduced into each ear. These frequencies when processed by the brain cancel each other out, creating a whole new frequency. So if we had a tone of 500 Hz in one ear and a 510 Hz tone in the other, the result would be a 10 Hz tone. So while a 10 Hz tone couldn’t be directly heard, using binaural beats we can create that tone inside our brain.
A popular opinion in the brainwave entrainment community is that listening to isochronic tones without music produces a much stronger effect. However, in the study by Doherty, Cormac. “A comparison of alpha brainwave entrainment, with and without musical accompaniment” (2014), it was concluded that brainwave entrainment was equally effective for isochronic tones, both with and without music.
This is something which will come to you with practice. For instance you may feel an energy around and inside you like you have shifted dimensions but are still there. Instead of thinking this is God, the Zone or whatever, think of this as your soul, you essence, your expanded pure light being. In this way you will begin to train yourself to find your identity in your expanded being and your internal identity. This is what we want - to let go of the idea that we are a limited ego.
A study published in Electroencephalography and Clinical Neurophysiology by Paul Williams and Michael West in 1975 examined the brainwave states of people experienced in meditation while using photic stimulation, and another study by Leonard, Telch, and Harrington in 1999 examined the successful use of brainwave entrainment techniques for attaining meditative states in subjects.
Gamma waves are the most recently discovered brainwave, a discovery made possible by digital EEG technology. Gamma is associated with the integration of information from different areas of the brain, and having a good memory is associated with having a certain baseline of 40 hertz gamma activity. Low gamma activity is associated with learning disabilities and poor memory.
A more extensive study of over 100 participants who were undergoing general anesthesia for a day procedure, reported a decrease in pre-operative anxiety. The participants in this study listened to 30 minutes of binaural beats before surgery, but the researchers noted that people experiencing high levels of pre-operative anxiety could listen to binaural beats for up to 1 hour before anesthesia to reduce levels of anxiety.