Hi Indi and Sherri,

As I understand things, the non-headphone type of 'induction' is not entrainment based. In other words, entrainment can not be accomplished using sound which is not algebraically integrated between the brain's hemispheres and therefore is not 'entrainment', but something else, possibly a sham.

Here is the physics of how entrainment works. First, understand that the brain exhibits specific electro-chemical behaviors depending upon the mode of the activity of the brain at any given moment. I at one time could recall ALL of the modalities and their requisite neuro-rythms, but frankly, I am only interested in Theta these days. Theta is the neuro-rythm which enables the brain and commensurate consciousness to move into Yetzirah or the lucid-dreaming state...eg, dreaming awake. Yetzirah is a useful state as it is in this state where certain psychic function transpires.

Sleep, relaxation, lucid dreaming and other states exhibit specific neuro-rythms and frequencies. Normally our brains move into these states autonomously and often with out our pre-knowledge or direction. However, one can initiate artificially these states by introducting into the brain's cognition a MORE DOMINATE RYTHM, or a rythm which has a stronger 'signal' than that of the brain's present rythm. This process is known as "ENTRAINMENT", and now here is the catch. These frequencies are outside of the Human ear's ability to hear or commute to the brain through the auditory channels. Take Theta rythm as example, its frequency is typically (can vary from individual to individual for a variety of reasons), around 3 to 7 Hertz or cycles. Human's can not hear this narrow spectrum, so how can one get this 'sound' into the brain, easily and cheaply? Neuro-researchers can directly stimulate the brain in a variety of ways, all of which are outside of the lay persons pocket-book and technical skill level. The Monroe Institute discovered that by simply putting two Human hearable tones, one each into each ear, with a slight mismatch in frequency, that the brain algebraicly integrates as one much lower tone. For instance, one requires a frequency of 5 Hertz, so, put 400 Hz into the left ear and 395 hz into the right ear and the brain hears:

400 Hz
-395 Hz
====
5 Hz, and if the resultant 'tone' is of sufficient magnitude or power, the brain will move to following that rythm 'forgetting' its own.

Simple huh?

With non-headphone usage CDs, the algebraic brain signal-processing can not work, as the brain only hears the two at once and the algebraic integration does not take place. So how these AUDIO CDs work, is a mystery to me, and I suspect that they do not, infact entrain the brain.

Indi, depending on what calls you, I would stick with the BWG program and presets at least until you have exhausted all of the publically available (preferably created by knowledgable people) presets. I found hordes of these things, by searching using the Google Database Engine with, "BWG presets".

Best Wishes,

Love

walt