Hi Et, In all the feedback and studies I’ve read and looked into over the years, I’ve seen lots of feedback from people talking about how they don’t like the sound of the tones, or they find them irritating in some way. Unfortunately, there doesn’t seem to be any particular reason why one person likes it and the next doesn’t. It’s a bit like normal music, one person’s sweet symphony is another person pneumatic drill. It’s common for people to find it weird and maybe annoying at first, which is how I felt in the beginning. But usually after a few listens you can start to get used to it and appreciate the sound, and especially the feeling it gives you. Personally, I think it can help if you try to embrace the sound, psychologically speaking beforehand. It can also help to have the sound playing at a very low volume, to begin with, then building it up as you get more used to 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.”

Binaural beats are the playing of two sine waves of close, but not the same, frequency into different earpieces of a set of headphones. The "beat" is heard as the brain tries to process them as a distinct sound, while taking into account the constructive/destructive interference. It is said to migrate brain waves to be closer to that frequency, like a sort of biological resonance, which is true. Of course the same can be said for listening to relaxing music help you relax, up tempo music to help you feel energetic, etc...
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.  
Brainwave Entrainment is the process of synchronizing the brain to specific frequencies and patterns embedded in audio tracks. These frequencies correlate to specific emotions, feelings, and even energy levels. Using nothing more than sound, Brainwave Entrainment can enhance creativity, change moods, and even alter behavior like sleep and energy levels.

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.
Subsequently, the term 'entrainment' has been used to describe a shared tendency of many physical and biological systems to synchronize their periodicity and rhythm through interaction. This tendency has been identified as specifically pertinent to the study of sound and music generally, and acoustic rhythms specifically. The most ubiquitous and familiar examples of neuromotor entrainment to acoustic stimuli is observable in spontaneous foot or finger tapping to the rhythmic beat of a song.