While it is no doubt that the technology does create changes in a person’s brain waves, whether there are valid scientific benefits resulting from those changes is up for debate. Self-reports from those that have engaged in various types of brainwave entrainment have made claims such as: the software helped treat my depression or improved my mental focus. These claims are often vague and could be subjective and/or a placebo effect.

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]
In 1956, the famous neuroscientist W. Gray Walter published the results of studying thousands of test subjects using photic stimulation, showing their change in mental and emotional states. He also learned that photic stimulation not only altered brainwaves, but that these changes were occurring in areas of the brain outside of vision. In Walter’s words:
For centuries, brainwave entrainment has been associated with a number of benefits. Of the range of brainwave states that exist there are four frequencies that are the focus of brainwave entrainment; each of these states has a different physiological effect and achieves a different result. What they have in common is the power to trigger your state of mind in order to get a specific outcome.

Back in 1839, Dr. Heinrich Wilhelm Dove, a Prussian physicist and meteorologist, discovered that when you introduce tones with certain frequencies into each ear, you could actually entrain the electrical patterns within the brain to resonate in very specific patterns, called brainwave states. The last two decades have seen an amazing amount of scientific interest in this world transforming field of study, laying the foundation for the hundreds of studies conducted since then, boosting the technology’s significance and importance immeasurably.
Another general benefit of using brainwave entrainment in general is that it increases and promotes whole-brain functioning, meaning that the two hemispheres of the brain grow more connections and exchange information more easily. This can help more starkly rational people become more intuitive, and more airy-fairy people become more focused and logical.
But again, when it comes to subjective experience, and mental evolution, I would have to caution you to take what anyone says with a grain of salt.  Obviously people want to sell these products.  There are some good ones out there and there are some bad ones out there.  There are differences in quality, as well as differences in intent with how the audios are to be used.
I have had your Equisync CD’s for a little more than 2 years. Some recent stresses prompted me to start listening to them again. Wow……these cd’s are no joke. I have been playing them consistently for the past 2 weeks and they are a tremendous help. I have to ask about the Equisync III cds. Can this elicit a detox reaction? I played it in its entirety one night and the next morning I felt like I was having a healing crisis. I am not complaining 🙂 I believe these particular cds allows tremendous amounts of healing light to enter the body through the higher chakras.

There basically are a few things that you can use to deduce whether you think these claims are true, and will work for you.  A few manufacturers of this type of product have taken the time to hook up experienced meditators (like zen monks) to encephelographs, then fashion their audios to mimic what is occurring in these deep meditators’ brains.  It would make sense then, to a large degree, that you could experience similar benefits from your brain undergoing this process. 

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.