+++ The sample contains four short excerpts from ten premium tracks included in this audiobook. +++ When you strike a tuning fork and place another tuning fork next to it, the second one begins to vibrate at the same frequency. A similar principle is often used to describe brainwave entrainment. In brainwave entrainment audio, gentle rhythmic frequencies are used to stimulate the brain's natural electrical activity. Many listeners find that this type of sound stimulation supports deep rela...