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.
, 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:[5]

This can help develop the ability to see energy fields around people and in nature, and it will also make it much easier to stay awake during your meditations. When your eyes begin to close, you simply have to open them back up again. Doing the meditations with your eyes open is a serious step up in exercising your brain, so go slow with that technique at first.
Gaia Meditation Delta programs are specifically designed to: improve sleep and healing process. Effects happen at a very deep subconscious level, ideal for powerful reprogramming. If you’re in lack of sleep because you’re a busy business man or because you have insomnia etc., a few hours of our Delta waves programs will trick your brain into thinking it had all the restorative sleep it needs.

Brainwave entrainment is a colloquialism for such 'neural entrainment', which is a term used to denote the way in which the aggregate frequency of oscillations produced by the synchronous electrical activity in ensembles of cortical neurons can adjust to synchronize with the periodic vibration of an external stimuli, such as a sustained acoustic frequency perceived as pitch, a regularly repeating pattern of intermittent sounds, perceived as rhythm, or of a regularly rhythmically intermittent flashing light.
It sounds like your brain might have initial trouble adapting to the binaural beats. The same thing happened to me when I listen to the Beta frequency (I got a headache), but then I discovered that I had the volume turned up too loud. I would say experiment with these frequencies, but at a low volume. See how you go. And if you continue to have anxiety, by all means, stop listening. Also, not all binaural beats are created equally. Some are amateurish, but the ones from Binaural Beats Meditation (mentioned and linked to in this article), are professionally created and the ones that I personally listen to. I love them (especially the Theta/Delta ones)! I hope this helps. :)
^ Bittman, B. B., Snyder, C., Bruhn, K. T., Liebfreid, F., Stevens, C. K., Westengard, J., and Umbach, P. O., Recreational music-making: An integrative group intervention for reducing burnout and improving mood states in first year associate degree nursing students: Insights and economic impact" International Journal of Nursing Education Scholarship, Vol. 1, Article 12, 2004.

Theta brainwaves in the frequency range of 6 to 9 hertz are known as thalpha waves because of their proximity to alpha waves. They are seen during states of high suggestibility, during hypnosis, and during paranormal experience and are also connected to an increase in human growth hormone (HGH) levels and higher blood flow to the brain. Theta brainwaves sit between the realms of the subconscious and conscious mind, making them an especially useful brainwave state for developing creative thinking, working through emotional problems, and integrating subconscious and conscious experience. 

Theta waves have a frequency between 4 and 7.5 hertz, making them slower than more wakeful alpha but faster than the dreamless slumber of delta. Theta brainwaves are the frequencies of nighttime dreams and REM sleep when the brain goes through bursts of activity and eye movement. People also experience theta waves in a state of light sleep, deep relaxation, during meditation and prayer, and when daydreaming. Theta waves produce an experience of inward wakefulness where we become disengaged from the outside world while engaging in inner activity. At the lower frequencies of theta, sleeping states are experienced, and at the higher range of frequency, awake relaxed states are experienced. 
Reading can be a wonderful (and healthy) escape from the stress of everyday life. Simply by opening a book, you allow yourself to be invited into a literary world that distracts you from your daily stressors. Reading can even relax your body by lowering your heart rate and easing the tension in your muscles. A 2009 study at the University of Sussex found that reading can reduce stress by up to 68%. It works better and faster than other relaxation methods, such as listening to music or drinking a hot cup of tea. This is because your mind is invited into a literary world that is free from the stressors that plague your daily life.
The Frequency following response (FFR), also referred to as Frequency Following Potential (FFP), is a specific response to hearing sound and music, by which neural oscillations adjust their frequency to match the rhythm of auditory stimuli. The use of sound with intent to influence cortical brainwave frequency is called auditory driving,[39][40] by which frequency of neural oscillation is 'driven' to entrain with that of the rhythm of a sound source.[41][42]