One larger and more recent randomized and controlled trial looked at the use of binaural beats in 291 patients admitted to the emergency department at a hospital. The researchers observed significant decreases in anxiety levels in patients exposed to audio with embedded binaural beats compared to those who listened to audio without binaural beats or no audio at all (headphones only).
Alpha Waves are electromagnetic oscillations in the frequency range of 8Ð12 Hz arising from synchronous and coherent (in phase / constructive) electrical activity of thalamic pacemaker cells in humans. They are also called Berger's wave in memory of the founder of EEG. They place the brain in states of relaxation times, non-arousal, meditation, hypnosis

Hi Sahil, it’s hard for me to speak about other people’s tracks and videos, as I don’t know how they created them either. If you’re interested in a particular track/video and unsure about it, try asking the creator a question or two about the track, what frequencies were used and for how long, what software they used etc. Then make your own judgement based on how they reply to you. Jason
Gamma brainwaves occur during creative thinking and processing of memory and language and in many learning activities. These brainwaves are not present at all when a person is under anesthesia, but return as soon as the person becomes conscious again. Multiple scientific studies have shown gamma brainwave entrainment to be helpful for reducing distractibility, improving short-term memory, improving motor coordination, and relieving migraine headaches.
While a practical understanding of brainwaves has been around for as long as people have been singing, chanting, and drumming, a scientific view of the electrical activity inside the human brain was not published until 1924 when German psychiatrist Hans Berger developed a machine for sensing and recording activity in the brain by attaching small electrical sensors to the scalp of his patients and recording the resulting electrical activity. Berger’s inventions and discoveries were built upon the earlier work of Richard Caton who published animal studies on brainwave oscillations in 1875.

♥ I admit that I do not know much about brainwaves and can be swayed by suggestion (ah, the fickle subconscious), but since using this machine and sort of hiding the noise with other sounds or my own music so it is not so obvious to me, it has helped me get through my email correspondences and other online tasks with the focus that I need. Thank you so much for making this!
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. 
You don't have to buy one, though. It's not too hard to make your own binaural beat, and free software is widely available to do just that. The one that I used to make that little sample is an open-source program called Gnaural, available on the Sourceforge website. It's pretty easy to use, though it takes some practice before you can generate some of the really cool, more professional sounding beats. A binaural beat consists of two simple tones, and most people add that background pink noise. Nothing special.