According to wikipedia, '"
Brainwave entrainment or "
brainwave synchronization", is any practice that aims to cause brainwave frequencies to fall into step with a periodic stimulus having a frequency corresponding to the intended brain-state (for example, to induce sleep), usually attempted with the use of specialized
software. Entrainment is defined as the synchronisation of two or more rhythmic cycles.
Since time immemorial humanity has used this knowledge, either by the beating of a drum, or as Ptolemy did in 200BC, by the flickering of sunlight generated by a spinning wheel, to stimulate the brain into various states of consciousness. When the brain is presented by a regular stimulus, the rhythm is reproduced in the brain.
Brainwave entrainment was first identified in 1934, though its effects were noted much earlier,
