Cortisol is the principle hormone (although not the only hormone) tied to our innate “flight-or-fight” response, which is how the body reacts to acute stress by either helping us run from the situation or stick around and fight our way through. When short spikes in cortisol/adrenaline happen over and over again nearly every day, they cause wear and tear on the body and speed up the aging process.

When you hit a tuning fork, tuned to a particular sound frequency such as the note B, and hold it close to the strings of a guitar, you will notice that the B string on the guitar will vibrate because it has entrained on to the same frequency of the tuning fork. Interesting enough, the other strings will not vibrate. Only the one with the same tuning as the tuning fork.
The brain is composed of millions of specialized cells called neurons. Neurons send signals to other neurons using electro-chemical messengers called neuro-transmitters that attach to receiving sites located on the neurons themselves. There is a space between the end of the neuron and the receptor called the synaptic gap. As neuro-transmitter chemicals move across this gap, a small electrical charge is created. 

The pitch frequency measures and describes what a beat sounds like, i.e. does the isochronic beat have a deeper bass sound, or is it high pitched and sharper sounding? The beat waveform frequency describes how many times the beat is repeating per second, i.e. how fast it is beating. You don’t really need to concern yourself about the pitch frequency, as that doesn’t have a direct influence on brainwave entrainment and doesn’t play a part on the measurement on an EEG. I only mentioned it because you were referring to humans not being able to hear below 20Hz. I change the pitch frequency just to suit the mood of the track. For tracks that are to be relaxing, for meditation or sleep, I tend to use a lower pitch frequency so it sounds deeper and more relaxing and I never have that lower than 100Hz. For an energizing, high focus track I might use a more higher pitched 200Hz isochronic tone, because that is sharper sounding and less likely to make you feel sleepy. That’s all you really need to know about the pitch frequency.

Our brainwave states are natural. Guiding the brain into those states intentionally by using entrainment is just another way of experiencing those same natural states. Nothing “unnatural” is produced by the brain as a result of using entrainment. The only thing that is different is that when using entrainment we often go into the experience with either general expectations, or a well defined laundry list of specific expectations that we associate with entrainment. We have no such list going throughout our normal day when we’re not using entrainment.
Most programs start at a work/life busy brain Beta frequency of twenty light flashes per second (20Hz) and slowly ramp them down to Alpha (relaxation and meditation) at 8-12 HZ, Theta (deep relaxation and dreaming) at 4-8 Hz) and Delta (dreamless deep relaxation) of .5-4Hz. We have taken measurements at Mass General with state of the art EEG equipment and have seen a slowing of the brain waves from Beta to Theta in two minutes and complete brain wave harmonization in the left, right, anterior, posterior and occipital regions of the brain.
Aletheia Luna is an influential psychospiritual writer whose work has changed the lives of thousands of people worldwide. After escaping the religious sect she was raised in, Luna experienced a profound existential crisis that led to her spiritual awakening. As a spiritual counselor, diviner, and author, Luna's mission is to help others become conscious of their entrapment and find joy, empowerment, and liberation in any circumstance. [Read More]
Sensorimotor rhythm (SMR) is one final type of brainwave that has been studied. SMR, also known as low beta, is a type of brainwave, which occurs in the sensorimotor cortex, in the 12 to 15 hertz range when that area of the sensorimotor cortex is idle and immobile. The purpose of SMR brainwaves is not well understood, but some neurofeedback practitioners report training to increase SMR brainwaves can be beneficial for people with autism, epilepsy, ADD, insomnia, drug addiction, and as an aide to better manage stress.

Theta is very subtle. It is one of the most elusive and extraordinary brain states you can explore. Theta is a state of somnolence with reduced consciousness; you are neither fully awake nor asleep yet. It is also known as the “Twilight state” or “Stage 1 Sleep” which you normally only experience fleetingly as you wake or drift off to sleep. In the Theta brain state, your senses are withdrawn from the external world and focused on signals originating from within.
A potential and generally desired result of brainwave entrainment is hemispheric synchronization. It refers to a state when the brainwave pattern of the right and left hemispheres become alike. It is said that a person with similar activity in both hemispheres tend to be happier, more optimistic and more emotionally stable and less prone to mental illness. Studies found that increased levels of synchronization are found naturally in people who meditate regularly and people who are very happy with their lives in general.
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.
When tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies like in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception[1], the beating starts to sound like a note, and a combination tone is produced. This combination tone can also be referred to as a missing fundamental, as the beat frequency of any two tones is equivalent to the frequency of their implied fundamental frequency.

There’s also some new stuff I’ve certainly never included in tracks before including some gentle pink noise and brown noise blended together in the background with what’s called phase modulation. This is almost outside of awareness as you’re listening to it. This is how your ear tells what direction a sound is coming from. Does it arrive at your left ear slightly before your right ear? You can modulate that. So, again, it has a very gentle, imperceptible rhythmic quality to it.

Music therapy has shown numerous health benefits for people with conditions ranging from mild (like stress) to severe (like cancer). When dealing with stress, the right music can actually lower your ​​​blood pressure, relax your body and calm your mind. Here are some suggestions of different types of music to listen to, and how to use music in your daily life for effective stress management.
... The goal of the study was to observe the effect of exposure to BB on working memory capacity. As suggested by many studies, BBs corresponding to alpha brain waves can positively influence cognitive processing, namely attention, auditory sequential memory, working memory, working memory storage, and reasoning ability (Carter & Russell, 1993;Cruceanu & Rotarescu, 2013;Foster, 1990;Kennerly, 1994;McMurray, 2006). The results show that a BB of the frequency of 9.55 Hz – which is a representation of the alpha frequency range of the brain activity – had a temporary positive effect on working memory capacity in our sample of healthy, adult university students. ...

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]