Binaural beats were discovered in 1839 by a German experimenter, H. W. Dove. The human ability to "hear" binaural beats appears to be the result of evolutionary adaptation. Many evolved species can detect binaural beats because of their brain structure. The frequencies at which binaural beats can be detected change depending upon the size of the species' cranium. In the human, binaural beats can be detected when carrier waves are below approximately 1000 Hz (Oster, 1973). Below 1000 Hz the wave length of the signal is longer than the diameter of the human skull. Thus, signals below 1000 Hz curve around the skull by diffraction. The same effect can be observed with radio wave propagation. Lower-frequency (longer wave length) radio waves (such as AM radio) travel around the earth over and in between mountains and structures. Higher-frequency (shorter wave length) radio waves (such as FM radio, TV, and microwaves) travel in a straight line and can't curve around the earth. Mountains and structures block these high-frequency signals. Because frequencies below 1000 Hz curve around the skull, incoming signals below 1000 Hz are heard by both ears. But due to the distance between the ears, the brain "hears" the inputs from the ears as out of phase with each other. As the sound wave passes around the skull, each ear gets a different portion of the wave. It is this waveform phase difference that allows for accurate location of sounds below 1000 Hz(9). Audio direction finding at higher frequencies is less accurate than it is for frequencies below 1000 Hz. At 8000 Hz the pinna (external ear) becomes effective as an aid to localization. In summary it's the ability of the brain to detect a waveform phase difference is what enables it to perceive binaural beats.
But the question is: Does it have a special effect on the brain? A lot of people think so. The basic claim being made for binaural beats is "resonant entrainment". Entrainment, in physics, is when two systems which oscillate at different frequencies independently are brought together, they synchronize with one another, at whatever the combined system's resonant frequency is. Examples of entrainment occur in animals in nature; for example the chirping of crickets or the croaking of frogs. Synchronization of menstrual cycles in women is another example. Even people coming together and dancing with one another is a type of entrainment. The basic claim for binaural beats is that the perceived low-frequency beat will entrain your brain wave pattern, thus forcing your brain into some desired state.
A 2008 study at Hofstra University played two different binaural beats and a control sound (a babbling brook) to patients with high blood pressure. There was no difference between the groups. In one small study from Japan that was published in the Journal of Neurophysiology in 2006, they played various binaural beats to nine subjects, and observed the resulting EEGs. They found great variability in the results. Their conclusion was that listening to binaural beats can produce activity on the human cerebral cortex, however the cause was more likely a conscious auditory reaction and was not correlated to the frequency of the binaural beat. However, a 2005 study published in Clinical Neurophysiology found that they were able to induce a desired frequency in the EEG matching the phantom beat frequency encoded in a binaural beat, however this was with a single subject and was neither blinded nor controlled.
I have many new age, meditation, classical and jazz cds that I use for relaxation. This Steven Halpern cd is now my favorite one. I can listen to it for hours on end while I read, write, use the computer, or just veg out on the couch at home or lounge at the pool. I especially love the tracks with the ocean wave sounds mixed in with the electronic music. I definitely am in the theta brain wave state while listening to it, and I know that's the reason it is so much more soothing than any other cd that I own. It is really great for eliminating any anger or anxiety that I may be feeling. I believe it's also improving my sleep. I give this cd the highest possible recommendation!
This is probably the most popular choice of frequency. The theta state is a state of tremendous stress relief. The benefits associated with theta level relaxation include improved concentration, reduced hyperactivity and improved memory. While in a state of theta relaxation, one’s blood pressure, breathing and heart rate all slow to a much more restful and healthy level that promotes natural healing. During theta relaxation one may also experience vivid flashes of mental imagery as the mind opens to memories or subconscious information that is not available to the conscious mind during the normal waking state. The theta state is a very deep state of relaxation that is excellent for deep hypnosis and mental programming.
Ever wish a stress superhero could save you from the tension of traffic jams, chaotic meetings, arguments with your spouse, or a toddler’s tantrums? Well, you can be your own stress-busting superhero. Using your senses, you can tap into the power to reduce the impact of stress as it’s happening and stay in control when the pressure builds. Like any skill, learning how to ease stress in the moment takes time, experimentation, and practice- but the payoff is huge. When you know how to quickly relieve stress, you can stay calm, productive, and focused, no matter what life throws at you.
If new stressors are challenging your ability to cope or if self-care measures just aren't relieving your stress, you may need to look for reinforcements in the form of therapy or counseling. Therapy also may be a good idea if you feel overwhelmed or trapped, if you worry excessively, or if you have trouble carrying out daily routines or meeting responsibilities at work, home or school.
Yoga poses can also be great stress relievers. “Power posing” takes good posture one step further and can help you take control of your stress. “Consider using a superhero power pose to fight off stress,” Dr. Serani says. “Research states that posing like Superman—arms crossed, legs apart, and chin up—can bring forth feelings of strength.” In addition, some poses derived from yoga can also help you feel empowered (like the warrior pose) or calm (like the cat pose). “Shashankasana, or moon pose, can be done with buttocks placed on the folded legs and bending forward completely, head on the ground in front of the knees,” says Savita Joshi, E-RYT, MBA, B.E, a yoga therapist at Yoga Bharati. “During stress, one may stay in this pose longer with knees kept apart so that hips can lower down on to the heels and head touches the floor. This pose improves the blood circulation in the head region, and directs the vital energy toward it.”
By the 1980s, entrainment technology had merged with advancements in microelectronics technology, making it possible to develop even more sophisticated audio and visual brainwave entrainment products for the marketplace. In the last two decades, a number of scientific studies have reported brainwave entrainment as an effective remedy for ADD, academic learning problems, and improving memory and cognition.
When delta waves are present, our awareness of the external world decreases and shuts off. People with ADD have problems with delta waves occurring when they are trying to focus, and focus and attention become increasingly impossible with stronger delta waves. Studies show a reduction of anxiety, improvements in insomnia, and elimination of headaches when people engage in sessions of delta brainwave entrainment.
, that is, the average of the two frequencies. It can be noted that every second burst in the modulation pattern is inverted. Each peak is replaced by a trough and vice versa. However, because the human ear is not sensitive to the phase of a sound, only its amplitude or intensity, only the magnitude of the envelope is heard. Therefore, subjectively, the frequency of the envelope seems to have twice the frequency of the modulating cosine, which means the audible beat frequency is:
Recently developed entrainment software has been designed to correct specific imbalances in hemispheric activity associated with undesirable mind-states. For example, people suffering with depression often have more activity in the right hemisphere, and specially designed brainwave music decreases this activity while increasing activity in the left hemisphere, reducing depression.
These are just a few examples. This silly list literally goes on for pages and pages, and it is pure hogwash almost without exception. Unfortunately there are many people dealing with personal problems that read nonsense like this and want very badly for it to be true. Perhaps they don’t believe every word, but they believe or hope that at least some of it is accurate information. These hopes and beliefs contribute to the generation of false expectations, so that when listening to an entrainment frequency of 10.3Hz doesn’t clear up their stuffy sinuses they conclude entrainment doesn’t work. The digestion of such foolishness is an impediment to realizing the true value of entrainment.
Entrainment is like priming the pump of meditation. It doesn’t “cause” meditation any more than pouring that little bit of water into the pump initially “causes” water to appear in the well. The water was already there. The conditions for the pump to do its job just needed to be set up. What entrainment does is to create the conditions and the internal environment typically associated with meditation. You could get to that point without entrainment, certainly, but the entrainment allows you to get there quicker, more consistently, and to remain there for longer periods of time than you would ordinarily be capable of doing on your own.
When people begin to believe these kinds of claims it is only half a step further for them to begin to attribute all of their own curious little experiences to entrainment. After all, they reason in the back of their minds, if 3.84Hz can cure an ovarian cyst, isn’t it just as reasonable that listening to a track at 8Hz might cause the room to appear to spin and change colors? There is an old saying that suggests that the more outrageous a claim is, the more people will be inclined to believe it. Don’t fall for outrageous, ridiculous claims. If you do you’re heading for disappointment, guaranteed.