This sound features Theta waves at 4 Hz with a low, 150 Hz carrier tone.
Theta waves are linked to meditation, creativity, deep relaxation, and REM sleep. These waves are active during trance like states and are studied for their role in emotional processing and memory development.
Some believe that Theta waves are the 'door to the subconscious' and that they unlock intuition, creativity, and access to buried memories or spiritual insight.