Table 1.

Human Brain Band Waves. The human brain EEG power spectrum is divided into at least five band waves that are classified, depending on their frequency expressed in hertz (Hz), as delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (more than 13 Hz). Another category of very high (30–100 Hz) frequencies is referred to as gamma waves. Brain waves can be significantly altered when listening to sound. Thus, brain waves can change from a normal or even anxious state, like beta waves, to an exceptionally relaxed state (like alpha waves, theta waves, or even delta waves), while listening to relaxing music or through singing bowl sound meditation (for ref see [9]).

Band Waves	Frequency	Brain Activity	Wave Form
GAMMA	30–100 Hz	Gamma rhythmics are faster brain waves binding neurons and processing information from different brain areas.
BETA	12–30 Hz	Beta waves are the predominant rhythmic activity of the frontal cortex and are associated with alertness, active concentration, but also anxious thinking.
ALPHA	8–13 Hz	Alpha waves are the main rhythmics of the posterior regions of brain emerging during relaxation and resulting attenuated during brain stimulation.
THETA	4–8 Hz	Theta waves are rhythmics associated with relaxed creative states and can be observed during meditation, light sleep, or deep relaxation.
DELTA	1–4 Hz	Delta rhythmics are the highest amplitude and slowest waves, observed during deep dreamless sleep, or deep states of meditation.