Most of these websites give some brief explanation of entrainment. The example you hear most often is that of Dutch polymath Christiaan Huygens, who in 1665, hung two pendulum clocks next to each other on a wall. He noticed that the pendulums eventually matched each others' frequency, but always in antiphase, opposite to each other, as if canceling each other out. He'd try disturbing one or setting them in sync, but they'd always return to the same antiphase synchronization. Huygen's experience is widely touted on binaural beat websites as a demonstration of how systems can become spiritually connected through some energy field. However, they misunderstand what happened, and have not read the full story. Huygens also tried taking one clock off the wall, and as soon as they were no longer physically connected to one another via the actual wall, the effect disappeared. It was not the proximity of the clocks to one another that created the entrainment; it was their physical, mechanical connection to one another. As each pendulum swung it imparted an infinitesimal equal and opposite reaction to the wall itself. With two clocks on the wall, the system naturally sought the lowest energy level, according to the laws of thermodynamics; and both pendulums would thus swing exactly counter to each other, minimizing the system's total energy.
You know how movie characters always look themselves in the restroom mirror when faced with a tough situation? Well, giving yourself a quick pep talk in the looking glass can actually help relieve stress. “‘Mirror work‘ is done by looking in a mirror and vocally speaking positive affirmations to yourself with affectionate conviction, to release worry or to improve your self-confidence,” Whitaker says. To relieve stress in the moment, she suggests using a restroom mirror, your car’s rear-view mirror, or even a compact. “Calm your mind by saying encouraging affirmations aloud to yourself, such as, ‘I am excellent at what I do,’ ‘I’ve got this! I am amazing,’ ‘I am an asset to this company,’ or ‘I am awesome!’” she says.
I have seen 1.5Hz being linked to HGH, but also 4 or 5 other frequencies as well, so it’s difficult to know what may work if any. I haven’t seen any research relating to HGH and brainwave entrainment. It’s widely believed that 40Hz is the limit for achieving a brainwave entrainment effect, which is also where many believe the gamma frequency range begins. Once you get over 40Hz into gamma your brainwave activity isn’t likely to stay in sync with it. So from a brainwave entrainment perspective, I recommend high beta frequencies for increasing energy during workouts.
After fixation upon our phenomenon takes place, what started out as a random perception is now cemented into our experience of, and is conditionally associated with entrainment. We condition ourselves to relive the same experience associated with entrainment each time we use it. It isn’t random any longer. It is explicit conditioning, and it repeats as predictably as the sunrise using entrainment as its new trigger.
Several adaptogenic herbs and essential oils have been shown to improve anxiety symptoms by reducing the effects that stress and cortisol have on the body. Adaptogens (including ginseng, ashwagandga, maca, rhodiola, holy basil and cocoa) are a unique class of healing plants that balance, restore and protect the body and make it easier to handle stress by regulating hormones and physiological functions.
Transparent Corp's Research Area is arguably the most comprehensive resource for collated brainwave entrainment research.   Update: the main research area on Transparent Corp's website is currently being updated, so it is offline.  However, you can still access their peer-reviewed research paper as a PDF here: “A Comprehensive Review of the Psychological Effects of Brainwave Entrainment“.
Your brainwave activity during sleep is largely distinct from your brain activity when you’re awake. (REM sleep is one exception to this—during REM, your brain is active in ways very much like when you’re awake.) During non-REM sleep, the slower, lower frequency theta and delta waves dominate, compared to the alpha and beta waves that are prominent when you’re alert and active.
Making time for connecting with the people around you, spending time outside and doing things you love with family, friends and your spouse are all stress relievers that are good for your health in many ways. Social connection is tied to longevity, since it helps people feel like they’re a part of something larger than themselves and helps give them perspective. Being outdoors has some similar effects, reminding people that they’re one piece of a much larger universe, lifting their moods and making it easier to get good sleep. (12)
Thanks for the reply. I am now clearer on ‘what’ is heard. Can you expand or point me in direction ..a bit more about ‘pitch frequency’ and frequency spoken about and what exactly is the difference ..and how we use the higher pitch frequencies to ‘hear’ or become aware of them? Would you only pick up the low freq on a EEG?. sorry for being pedantic still does not clear up split isochronics and possibly creating same situation as binaural beats..

The body responds in essentially the same way to made-up imagery as it does to real experiences. Positive, relaxing images can be an effective tool for relieving stress. Try it for yourself with this Guided Imagery podcast from our Founder and Director Dr. James Gordon, or check out Dr. Gordon’s book Unstuck: Your Guide to the Seven-Stage Journey Out of Depression for dozens more techniques, including scripts for guided imagery exercises.

Entrainment is a term originally derived from complex systems theory, and denotes the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in a context and at a proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force, such that they adjust until both oscillate with the same frequency. Examples include the mechanical entrainment or cyclic synchronization of two electric clothes dryers placed in close proximity, and the biological entrainment evident in the synchronized illumination of fireflies.[13]