“Binaural beats are not very noticeable because the modulation depth (the difference between loud and quiet) is 3 db, a two-to-one ratio. (Isochronic tones and mono beats easily have 50 db difference between loud and quiet, which is a 100,00-to-1 ratio). This means that binaural beats are unlikely to produce an significant entrainment because they don’t activate the thalamus.”

How does brainwave entrainment work? Consistent, precisely engineered audio frequencies in the form of binaural beats cause the brain’s frequencies to match the stimulus. Your brain perceives two beats with slightly different frequencies (which are inaudible to the ear) through your headphones. It takes the difference between the two, and matches its own frequency to it. This is called the “frequency following” response.

If you’re operating in Alpha mode, you’ll feel very present and in the moment. You might be somewhat reactive to the world around you, but you’ll feel like you have time to process what’s going on rather than just react on instinct. This is a wonderful state to achieve when meditating or doing something that requires coordination, focus and learning.
Hi Rona, thanks for your compliments on my videos and the music I use, I’m pleased you’ve found them helpful. Regarding the pulse-like sound you’ve been hearing, I’ve never had anyone report something similar to that before. I also haven’t heard anyone on brainwave entrainment forums mention it. That is very unusual and because I’ve never come across it before, I’m afraid I don’t know what would cause that.
Binaural beats, or binaural tones, are auditory processing artifacts (apparent sounds) resulting from the stimulation of the ears with two different sound frequencies. In fact, when two different vibrations are delivered to the brain separately through each ear, using stereo headphones, the two hemispheres of the brain function together to “hear” and perceive not the external sound signals, but a third phantom signal. This resulting signal, discovered in 1839 by Heinrich Wilhelm Dove, is called “binaural beat”. The effect on the brain waves depends on the difference of each tone. For example, if a sound frequency of 300 Hz is played in the left ear and 307 Hz in the right one, then the binaural beat would have a frequency of 7 Hz (“frequency following response”) which corresponds to the Alpha brain state, generally associated with relaxation, visualization and creativity. The beating tone is perceived as if the two tones mixed naturally, out of the brain. For the binaural beat effect to occur, the difference between the two frequencies must be small (less than or equal to 30 Hz), otherwise, the two tones will be heard separately, and no beat will be perceived.
Cory Allen [b. 1982] is a composer and mastering engineer living in Austin, Texas. His work focuses on the cultivation of human perception with the intent of altering the listener's state of consciousness. Allen's music is deep, patient, meditative, highly-conceptual and often composed by implementing self-organizing structures, rule-based performances, set pitch classes and a wide variety of instruments.
If you want the most results in the least amount of time, a well balanced approach is to listen to IQ Increase and Beta Relaxed Focus once or twice per day, and then use one of the 30 or 60 minute meditation tracks once during the day and again as you are going to sleep. That means a maximum of FOUR entrainment sessions per day. Trust me, that is a LOT of entrainment for your brain.
Using a small amount of alcohol in the Pregnancy and Children's lines was a conscious decision. It enables us to keep the strength and efficaciousness of the formula intact but is also gentle and appropriate for women and children. Extracts made with only glycerine or water limit the constituent profile. WishGarden's finished extract contains a minimal amount of alcohol, which, per serving, is at a very low dietary level (similar to what is found in kombucha and ripe bananas). You can also further reduce the alcohol content by stirring your droppers full, or pumps, into hot water or tea for a few minutes.
The final suggestion I have to offer is that you make your practice a regular, consistent habit. You don’t have to be perfect but you do need consistency. Like any other skill, entering meditation will develop in direct proportion to the consistency of your practice. Missing a session occasionally is not going to derail all your progress. But frequently skipping or blowing insincerely through practice is not going to produce any noteworthy results. There isn’t any hard and fast rule from frequency of practice that always applies to everyone, but most of us will instinctively know whether or not we’re giving our practice the time and effort it requires.
A study by Tina Huang, PhD, and Christine Charyton, published in the September 2008 issue of the journal, Alternative Therapies examined the results of twenty previous studies measuring the effectiveness of brainwave entrainment for improvements in cognitive dysfunction and deficits, stress reduction, pain management, migraine and headache control, pre-menstrual syndrome, and behavioral difficulties, and all showed significant improvement in symptoms using entrainment techniques.
Once you begin to experience the beneficial aspects of brainwave entrainment, you may be tempted to have these tracks playing all the time during your waking and sleeping hours. This is NOT advisable, nor is it necessary. Remember, brainwave entrainment is exercise for your brain so your brain will need to rest and integrate the new changes that your entrainment regime is creating.

Controlled or pre/post studies of the effects of BWE using auditory or visual stimulation were eligible for inclusion, provided pulses of light or tone were delivered at frequencies hypothesised to have a beneficial effect or in line with a protocol addressing clinical outcomes. Studies were required to report clinical or psychological outcomes (measured using standard methods or as deemed appropriate by peer review) and to report statistical analysis. Studies of outcomes such as electroencephalogram (EEG) response or neurotransmitter levels were not eligible. Case studies were excluded.

For our ancestors, stress was a survival skill during brief, life threatening situations. Once the danger passed, their stress levels lowered. However, in today’s world, we are constantly bombarded by stressors, such as work deadlines, traffic, and family obligations. We rarely get a break long enough to relax and relieve the stress. The over-activation of our stress hormones have been linked to high blood pressure, heart attacks, lower immunity, depression, anxiety, and more.
Turns out, science says there is something to needing “fresh air”—even opening a window can help get more oxygen to your brain, soothing stress. “We live so much of our lives indoors, that when stress hits, one of my go-to techniques is to get outside or open a window,” Dr. Serani says. “Taking in a nice deep breath of crisp fresh air can immediately shift your neurochemistry.” If you’re overwhelmed with work, it can seem hard to take a break; but a quick step outside is even recommended by the American Psychological Association. When you come back, you’ll be recharged and ready to take on the challenge.
The various mental states of the individual are thought to take place across a varied range of frequencies, or brainwaves. By encouraging the frequency following process, entrainment is able to create positive change in the brain, through matching carefully-selected frequencies of light and/or sound. The stimulus enables the individual to access a different state of consciousness, which can be useful for a number of benefits including relaxation, anxiety management, stress reduction and more.
So using the example track above, the right ear is sent a 20Hz beat, compared to a 10Hz beat in the left ear.  As the right ear receives the higher frequency of beat, this works to increase the speed of the ‘left' brain hemisphere, which can be helpful for people with conditions like ADD, who are often found to have an abundance of slow wave activity in the left brain.

From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.
It takes slightly more time to practice guided imagery, but this is a great way to leave your stress behind for a while and relax your body. Some find it easier to practice than meditation, as it allows more engagement of the conscious mind. You can focus on imagining relaxing environments you would love to visit, or on memories of your "happy place" for when you're stressed. You can play natural sounds in the background as you practice, to promote a more immersive experience.
Writing or talking about the things that prey on you—in a diary, with friends, in a support group or even a home computer file—helps you feel less alone and helpless. One study, published in The Journal of the American Medical Association, looked at people who had either rheumatoid arthritis or asthma— conditions known to be stress-sensitive. One group chronicled in a perfunctory manner the things they did each day. The other group was asked to write daily about what it was like, including fears and pain, to have their disease. What researchers found: People who wrote at length about their feelings had far fewer episodes of their illness.
“Stress and sleepless nights are closely linked,” Buenaver says. “If you’re in pain, tend to worry, or are coping with a difficult situation in your life, you may have more stress hormones than usual circulating in your body. A poor night’s sleep adds even more. And those hormones may never be fully broken down. It’s like running an engine in fifth gear all the time.”
Pure tones played together interfere with each other when they are close in pitch but not identical. When each tone is sent to a different ear, there will not be any physical interaction between the waves, yet your brain still creates an interference inside your head: the so-called binaural beat. In order to create a binaural beat, each ear must receive its dedicated signal. Therefore, binaural beats only work through headphones.
Brainwave entrainment is a field of study and endeavor founded in the same physiological and psychological processes that make music, drumming, and chanting so powerful as methods for transforming the mind and spirit and aiding in healing of the body. These processes involve how the electrical energy in our brains synchronizes with sounds and visual stimuli, producing a particular brainwave frequency and its associated mental states. 
Binaural beats are dual tones, each one slightly different from the other. You hear one tone in each ear and your brain responds by creating a tone to reconcile the difference between the two. Isochronic tones are single tones. The variation in pattern here is brought in by interspersing silence between the sound, which means that your isochronic tone does not have a continuous sound but tones broken up by silences. Studies show that isochronic tones have far more contrast than binaural beats because of the silence and sound pattern. This sharp contrast evokes a faster impact from your brain, prompting it to match the frequency more quickly. Also, isochronic tones are found to be stronger stimulants to the brain.
Your brain cells reset their sodium & potassium ratios when the brain is in Theta state. The sodium & potassium levels are involved in osmosis which is the chemical process that transports chemicals into and out of your brain cells. After an extended period in the Beta state the ratio between potassium and sodium is out of balance. This the main cause of what is known as "mental fatigue". A brief period in Theta (about 5 - 15min) can restore the ratio to normal resulting in mental refreshment.  
Theta waves have another interesting characteristic. The Earth has a measurable resonance of 7.83 hertz known as the Schumann resonance. Because the Schumann resonance is a constant background frequency surrounding all life, it may play a special role in biological activity. The Schumann resonance frequency falls within the range of theta brainwaves and may have something to do with why these brainwave frequencies are so powerful. 
There isn’t really a one-size-fits-all track or frequency range which is right for all kids while doing homework. So that does make it difficult to recommend one thing in particular, and why I have a number of tracks for studying and focus. If they have already learnt and understood the information, but are just trying to commit it to memory for a test, then I would recommend an alpha track, like the Memorization Study Aid product I have with the 10.4Hz frequency you referred to. If they are still trying to fully understand what is being taught in a workbook, then I would recommend a track that is mainly beta frequencies, like my Study Focus tracks. In the middle, I have a number of tracks which use a combination of beta and alpha wave frequencies, like Study Booster, Study Enhancer and Cognition Enhancer. The last 3 use similar frequencies but deliver the tones and brainwave entrainment effects in different ways. As we are all wired a little differently it does sometimes take a bit of trial and error, to see what method or frequency range works best for the individual. These types of tracks are made for a general audience. In an ideal world, you would hook up to an EEG and see in real time exactly what a person responds to best, depending on the goal and current state of mind.
Other than that the experience of those brainwave states is no different. Once we achieve a particular brainwave state using entrainment there is one significant difference to the experience and that is that we are usually still at a high level of consciousness. We’re not (hopefully) zoned out as we are when daydreaming or unconscious as we are when we’re sleeping. We maintain awareness and therefore we get to consciously experience what those brainwave states feel like in some detail.

“Stress” is a commonly used term, and it is often used with different meanings. The standard definition for stress that will be used in this article is the disruption of the body’s homeostasis or a state of disharmony in response to a real or perceived threat or challenge (8). The threatening or challenging situation is referred to as a “stressor.” When a person encounters a stressor, the body prepares to respond to the challenge or threat. The autonomic nervous and endocrine systems respond by producing the hormones epinephrine, norepinephrine, and cortisol. The result of this hormone production is a cascade of physiological reactions that make up the stress response. Epinephrine and norepinephrine are involved in the initial changes that take place to prepare the body to react and to prepare for a challenge. These responses include increases in heart and respiration rates, blood pressure, perspiration, and energy production (8). There also is a suppression of immune function, production of β-endorphin (the body’s natural pain killer), and increased acuity of the senses. These changes make up the fight-or-flight response, which prepares the body to cope with the stressor. If the stressor is perceived as negative or more as a threat than as a challenge, cortisol production is increased. Cortisol is involved in energy production but also suppresses immune function.
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“.
According to Dr. Mark Hyman, eating whole, real foods restores balance and reduces the effects of stress on your body. Replacing harmful substances such as caffeine, alcohol, and refined sugars, with clean proteins, fruits, vegetables, and healthy fats helps regulate your hormone levels, including stress hormones. Food As Medicine Education Director Kathie Swift, MS, RDN, LDN, FAND, EBQ cites the connection between the gut and brain in relieving stress. The gut and brain are constantly sending signals to each other, so by keeping your microbiota (the bacteria in your gut) healthy, your brain feels less stressed.

When explaining this to others they frequently respond with something like, “But I had no expectation or even any idea that my face might experience flushing. I didn’t even know that was possible. Now every time I listen to a particular entrainment track that specific face flushing occurs. If it is a specific phenomena, and it only happens when I use one certain entrainment track, doesn’t that prove it is the entrainment causing it?”
“In order to get into a flow state, you have to calm a part of the brain, the posterior cingulate cortex, which is the source of what brain scientists call the default state, which is the non-focused state,” says Harris. “At any rate, it turns out that Holosync [binaural beats], when you listen to it, [calms that part of the brain] and so does traditional meditation. It’s just Holosync does it faster and more easily and more effortlessly. It turns down the posterior cingulate cortex and it enhances the other part of the brain that, when it’s enhanced, you can easily go into a flow state.”
The aim of this study is to identify tendencies in the effectiveness of relaxing audio stimuli that could be verified through further focused experiments. A series of brainwave entrainment (BWE) techniques for inducing relaxation will be presented consisting of different binaural phenomena (BP). The BP will derive from the binaural sine wave beat, widely acknowledged in rhythmic BWE... [Show full abstract]
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.
I am very encouraged by my stroke recovery progress after starting with Sacred Acoustics! I have been listening to the extended Light Body (non verbal) recording almost constantly. I keep it on the repeat mode and at a low enough volume so that I do fine with ordinary conversation as I go about my daily activity. The results with constant listening of Light Body are so fantastic, I hate to stop! 

The heart meditation is amazing. The recording of sound, vibration and guided words were heartfelt. I felt energy in waves as I listened and felt various sensations of heat, tingling, and muscular tension release as I become one with the recording.  A sincere thank you for making these recordings available to us in search of an enlightened path with the help of sound and vibration. 
I have purchased the two meditations I mentioned which are theta and 7 chakra frequencies. I tend to be a bit hesitant to register and/or buy from sites I don’t know, that’s why I asked you. But I got over my trust issues and already wrote the creator. He is most helpful. In case someone is wondering: the ‘higher spiritual awareness’ refers to a deeply meditative experience.

Although there is a general stress response pattern, there can be variations in the response according to the characteristics of the stressor (10). Individuals tend to respond differently based on the familiarity of the stressor. For example, the perceived level of stress and physiological response when giving a presentation to a group of work colleagues will likely be less than when presenting to an unfamiliar group. The stress response also varies depending on the level of perceived control one has over the stressor (10). If there is a way for one to actively cope with the stressor that is reasonable, then the individual usually perceives more control over the situation. Consider an individual who has to take a certification examination for work and has 6 months to prepare. He can adjust his schedule to accommodate study time. However, waiting for medical test results that show whether one has a serious illness does not allow a sense of control over the stressor, and the individual passively endures the stressor or may try to avoid the stressor. With this uncontrollable type of stressor, there is a more negative reaction with greater productions of cortisol, which can have damaging health effects because of the suppression of immune function (10).
The studies included in the recent reviews of Tai Chi and yoga indicate that sessions between 60 and 90 minutes performed 2 to 3 days per week were effective in reducing stress and improving feelings of well-being (7,14,17). A study conducted in a worksite environment showed that 15 minutes of chair-based yoga postures was effective in reducing acute stress when assessed by self-report and with physiological measures (e.g., respiration rate and heart rate variability parameters). This finding indicates that shorter duration sessions can be effective in reducing acute stress with this type of exercise (15).
For those who accept that we are spiritual beings currently experiencing a physical existence, with consistent practice of meditation and brainwave entrainment, you get all of the above, plus; a deeper feeling of connection and oneness with all things; a heightened sense of relationship with the Divine, whether you believe in an anthropomorphic God or just an All-Inclusive Presence; more peace and confidence in the Divine and less reliance on dogmatic policies and practices (this is not to say that dogma and ritual do not have their proper time and place!); more freedom from the fear of death; greater hope for that which comes after this life; a greater appreciation for and sense of relationship to others, even when others act in ways that are not in our personal best interests, and much, much more.
It is also possible that some people experience headaches which are almost always the result of the binaural waves. Fortunately LifeFlow can also be used without headphones, since it contains not only binaural waves but other forms as well. If you’re one of the people who suffer from headaches using entrainment, you can take off the headphones and use LifeFlow over open speakers. This usually solves the problem.
4. Be hesitant committing to any BWE system making wild claims. Profit fueled marketers with little to no experience in the BWE field have created a slew of low-quality entrainment systems on the market. These products typically make outrageous promises such as permanently enhancing the brain within minutes of use. Although BWE is a powerful method to improve the mind, it’s not a magic bullet.