Brainwaves coming up during the transition period of sleep or slight relaxation are scaled somewhat lower. Alpha-frequencies cover waves from 8 to 12 Hz. The individual is just ready to get up or relaxes without getting asleep. At this phase the soul is open and ready to accept stimuli, which may influence its brainwaves and which may reach its subconsciousness.
Alpha waves are emitted low on the frequency spectrum between 8 and 12 Hz, mostly in that twilight time between sleep and awakening or when the awakened body is truly relaxed.
Practioners of brainwave music such as binaural beats and isochronic tones say that when alpha brainwaves are most prevalent is a time of great opening for the soul, allowing listeners to tap into their subconsciousness through aural brainwave stimuli. This so-called brainwave entrainment has existed since early cavemen found rhythm on drums, but has become refined to include entrainment devices that include both aural and visual stimulation (called mind machines).
The parapsychological field of hypnagogia pertains exclusively to the states of consciousness accessible going to and coming from sleep and the alpha brainwaves produced during this period. For this time, certain types of binaural beats are recommended to accomplish a more relaxed state in waking, learn more fluidly or prepare mentally for a sporting competition.
Alpha brainwaves are just one type of signal the brain is entrained to respond to and create. EEG tests also detect beta frequency brainwaves, between 12 and 40 Hz. this is the awake human. Theta brainwaves, from 3 to 8 Hz, happen during periods of meditation or dreamless sleep. Finally, Delta (brlow 3 Hz) and Gamma (above 30 Hz) are the deepest levels of both sleep and alertness, respectively. Much of these frequencies are outside a person's ability to notice.
Scientists have found that the higher a person's frequency, the higher that person's level of stress tends to be, though other factors must be considered. Music can be applied to relieve that stress and promote relaxation or, conversely, to stimulate concentration.
The Theta and Alpha waves are especially ripe for tapping into and stimulating the subconscious, typically first with Alpha waves during the beginning of a relaxation period and finishing up with a Theta-tuned sequence of beats. These are geared more toward someone who is starting to meditate, deeply relaxed or just done-for-the-day asleep. Quickly go from Alpha brainwave to Theta brainwave recordings, as many recordings do, and it could be just the nudge your subconsciousness has always needed. Or at least your dreams may be more vivid tonight.
A common theme through all Theta and Alpha brainwave recordings is a calmingly redundant, barely perceptible rhythm that mimicks the quicksilver and steady rhythm of the brainwaves themselves. The recordings will often include gentle breezes, distant birdsong or the slow progression of deep synth notes. But that's just what you can hear. Many of the recordings are produced with equipment capable of creating sounds set below what's perceptible to the ear, anything below 16 Hz. These shifting tides of frequencies are still getting through, though, below the 16 Hz level, stimulating the connection between the subconscious and conscious mind.
Through monaural beats, binaural beats or isochronic tones, or a combination of all three, the headphone-wearing public is invited to stimulate the alpha brainwaves if attempting to calm anxieties. Listening to Theta frequencies, on the other hand, is geared more toward helping people sleep but may also help some to "clarify hidden issues" and "transfer information from the subconscious into the conscious" in what some describe as similar to out-of-body experiences.