The relaxed time just before the one goes to sleep is known as alpha waves. Alpha waves are waves of the waves found in the brain at the time of relaxing just before one sleeps or closes his eyes. These are the most common waves one can found in people at relaxed time just before sleep.
These are waves that help in sleep and associated with meditation like the state to calm and relax the mind of an individual. These are found in between 8 to 12 Hz.
