Different states of mind are associated with specific brainwave frequencies that would be inaudible if played directly. These frequencies can be induced in the brain indirectly by playing two different audible tones into each ear, which after being processed by the brain, are perceived as an inaudible beat matching the target brainwave frequency. As you listen, your own brainwaves fall into step with this inaudible beat, and after a few minutes synchronize with the target brainwave frequency. Brain Wave's 35 programs layer these binaural sequences into multi-stage sessions that have helped thousands of people focus and concentrate, feel positive and motivated, and sleep more soundly.
Isochronic tones are basically just a single tone with the volume being turned on and off at regular intervals. When you apply the same effects to music or a noise, it’s usually referred to as amplitude entrainment effects (in Mind Workstation anyway). When you apply the on/off effect to music or noise it’s usually done by targeting a specific frequency range in the sound and only turning that part on/off, leaving the rest of the music/noise untouched. What that does is allow parts of the music/noise to play without being distorted/interrupted, making it sound more pleasant to listen to. It produces a kind of fluttering sound as I like to call it and you can adjust the level of intensity.
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.
So often it is presented as such a highly scientific technology that can only be created by “experts”. Buzz words like “scientific”, “certified engineer”, “frequencies”, “cortical evoked response”, “anterior brain activity”, are used to make it seem over-complicated, and pseudo-scientific pictures of “data” and “brain readings” are pasted all over sites to further qualify claims of how powerful and amazing these people’s product is.
I forgot to tell you, after using your meditation for a few weeks, I woke up one morning with the most vivid recollection of having an out of body experience […shortened…] I am hoping to experience this again and control myself the next time. Thank you for enabling me to remember this extraordinary experience. I never believed they were real until I used your program.
The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.[4][5]