I was diagnosed with “acute high anxiety, major clinical depression,and ptsd” 16 years ago. I have clinically addressed these disorders with a number of medications, which none have helped. I am so lucky I have found this simple easy to practice method of practice, that I have found these beats and tones so essential that I indoctrinated them into my daily life, and have come to the realization, that someday very soon I will awake and will not suffer from these burdens these disorders ever again.
The fastest way to make brainwave entrainment technology work for you on your path of spiritual development is to pull back ever so slightly once you realize you have reached the peak of your nervous system’s capacity to recover from the stimulus. Because your nervous system is like a sine wave, when it is about to go into its valley, you pull back just a little bit, thereby giving your nervous system, energetic system, and hormonal system enough room to pull out all of their recovery powers. This allows you to recover from stimulus more quickly, and then you get past the waning stage and back to the waxing stage, where you can start pouring on the juice a little bit more again.
Biofeedback enhancement: In 1981, researcher Arturo Manns discovered that 15 minutes of stimulation with isochronic tones enhanced biofeedback protocols for bruxism (grinding of teeth). They did this by increasing muscle relaxation superior than standalone biofeedback. Brainwave entrainment is different from biofeedback in that it does not allow the person to consciously control their brainwave state.
The main gist of brainwave entrainment audios, without getting too technical here, is that they effortlessly guide one’s brain (when listened to with stereo headphones) into a specifically targeted state, as designated by the creator of the audio. They are able to alter your brainwave states through the use of specific audio frequencies, and specific beats-the most common of which being binaural beats (though there are other types of beats being used as well).  When one frequency is played into one ear- let’s say 1115 Hz- and a slightly different frequency is played into the other-say 1125 Hz- the brain is forced to reconcile the two, and creates its own “phantom” frequency that is the difference between the two- in this case 10 Hz.  Not only does this allow the brain to be led into specific brainwave states, but it also allows the two hemispheres of the brain to synchronize with each other, stimulating and promoting whole-brain functioning.
However, yoga and meditation take time to learn and master, and until the student becomes proficient, progress can be slow and frustrating, leading many people to abandon the effort before they see the benefits. Brainwave entrainment has the potential for helping a person enter the relaxing and rejuvenating mind-states brought about by yoga and meditation without the learning curve and time needed for mastering these other techniques. Brainwave entrainment may even facilitate learning other mindfulness methods by helping a person achieve success faster and more reliably. 

Behavior problems: In two separate studies with a total of 57 children, it was found that brainwave entrainment was able to significantly improve behavior problems. One of these studies was conducted on children with ADHD and determined that they significantly improved not only in regards to attention deficits, but also in their behavior. Both parents and teachers reported statistically significant improvements in how the children behaved.

Most wisdom traditions have employed methods that allow the subjects' brain waves to slow down such as meditation, [Hindu] kirtan, [Gregorian, Menzuma or Sufi] chanting, Hebrew davening, Native American drum circles and rain chants, Tibetan prayer bowls, and whirling dervishes and African trance dancing. The rhythm of these wisdom tradition technologies actually slows people's brain waves from their normal busy brain frequency we call Beta (13-30 cycles per second or Hz), to Alpha (8-13Hz) -- meditation, Theta (4-8Hz) -- deep relaxation and dreaming, and Delta (.5-4Hz) -- slow wave or dreamless sleep.

1) Theta Music Meditation from Unexplainable Store. Yep, you guessed it, this is a meditation MP3... with music. Boom. This is a nice, simple, powerful 20 minute session and (like all my recommendations) guaranteed 100% to work every time. Find yourself drifting away with this awesome recording, and start to reap the benefits of your underused theta brain waves. Simple and understated, my favourite.
A study that tested photic stimulation for reduction of poor behavior in ADHD children found that 15 sessions of photic stimulation between 12 Hz and 14 Hz resulted in behavioral change. This behavioral change was measured using the Achenbach Child Behavior Checklist – which accounted for not only the parent’s perspective, but self-reports from the children. Statistically it was stated that behavior improved up to 70% in the stimulation group compared to controls.
One can also learn to control and slow down their brain waves through various neurofeedback technologies such as electroencephalograph (EEG), galvanic skin response (GSR), and heart, pulse and breath rate monitors. These devices measure stress and relaxation parameters and then "play" back the signals to the user so they can use the signals as a beacon to guide and "steer" themselves into a relaxed state. This takes some time, work and discipline but is much quicker than learning meditation.

There are differences between high (over 18 hertz), mid (15 to 18 hertz), and low range beta states (12 to 15 hertz). Low beta states are more relaxed while still being focused, making this a good range for many daily work related tasks like balancing a checkbook, making a shopping list, or driving to a new place. However, people with attention deficit disorder lack the mental focus for doing these types of activities, and studies have found people with ADD are often low in this range of beta brainwaves.
After nearly two years of daily use of this brainwave meditation and brainwave technology, I began to enjoy a quality of life–without medication–that once seemed quite impossible for me. I do not say this lightly. Not only did I enjoy a fulfilling life, I also experienced what seemed like significant development in self-concept, values, interpersonal skills, creativity, accelerated learning, intuition, ability to handle stressful situations, self-esteem, sense of purpose, and social awareness.
Learning: Since performance improves among those with ADHD and cognitive function may be boosted, one may hypothesize that learning would also improve. Those that are struggling to learn as a result of inattentiveness may benefit from stimulation with beta frequencies. Deficits in learning tend to be associated with abnormal or excess slow wave frequencies.
2) You are being dissociated – When using AVE, you get drawn into the present moment and let go of thoughts relating to your daily hassles, hectic schedules, paying bills, worries, threats or anxieties and stop the unhealthy mental “chatter.” Dissociation involves a “disconnection” of self from thoughts and body awareness, as is experienced during deep meditation. Dissociation begins in four to eight minutes from properly applied AVE.
Dissociative but not present. In college I started having difficulty with reading comprehension/absorption (not dyslexia, I could read everything out loud easily but not gather the meaning). Over the past two years or so, my memory has been concerning, as I am not middle or late aged. Since it had been getting worse, I have been researching for several years now for a cure. Biofeedback led me to neurofeedback (which I can’t afford at the moment).
With each pulsed tone, the brain produces an electrical response. The effects one experiences are the creations of the brains reaction to the “tones”, what neurologists call the “cortical evoked response” (the electrical response of the top most cortical layer of the brain). The brain is a mass of neurons, each taking part in storing, retrieving and transmitting electro-chemical impulses: information, colors, images, sounds, smells and tastes. Brainwave entrainment stimulates different areas of the brain allowing for the awakening and subsequent release of various levels of stored material. It also has an effect of  quietening the mind for clearer thought and process.

While binaural beats are the most common technique we use for producing brainwave entrainment music, we do use other brainwave entrainment techniques such as isochronic tones, monaural beats and amplitude modulation. If these techniques have been used then you will find them mentioned in the written description of the music productions that include them. If not mentioned, then you can assume that binaural beats are the only brainwave entrainment technology in use.
Insomnia: Perhaps one of the most promising uses of brainwave entrainment technology is for those struggling with insomnia. While the technology is unlikely to provide a “cure” it may help those who have a high level of arousal or are “keyed-up” – reduce their level of internal arousal and sleep. Specifically insomnia that is induced by excess stress (e.g. beta activity) would likely benefit from slower wave stimulation (e.g. alpha activity) to aid the brain in transitioning into sleep.
That all said, we are all different and have our own different limits. So I generally advise that you just be aware of how you are feeling, and if you feel like you are getting a bit fatigued from it, it’s probably time to stop or at least take a break. When listening over long extended periods, I recommend that you keep yourself well-hydrated. Your brain needs a good supply of water to function well, especially if you are studying hard and increasing your brainwave electrical activity.
Neural oscillations are rhythmic or repetitive electrochemical activity in the brain and central nervous system. Such oscillations can be characterized by their frequency, amplitude and phase. Neural tissue can generate oscillatory activity driven by mechanisms within individual neurons, as well as by interactions between them. They may also adjust frequency to synchronize with the periodic vibration of external acoustic or visual stimuli.[3]