Because the lowering of carrier frequency—or pitch—is capable of providing more of a sense of “fullness” and “drive” to a binaural brainwave entrainment stimulus, it is often mistakenly assumed that such lowering of carrier frequency actually increases the ability of the entrainment stimulus to attract neural activity into its train of influence. This is not so.
Scientific research has shown that people tend to entrain better to higher carrier frequencies then lower ones. Simply stated, lower carrier frequencies are generally less capable of entraining brainwave activity than higher ones, unless the brain is trained to do so through consistent daily practice. (More on this in a little bit.) This is due to the fact that overall sound energy (i.e., its number, or frequency, of oscillations) decreases with the lowering of pitch.
What carrier pitch loses in overall energy when decreased, however, it gains in capacity to resonate physical matter—including the brain—more forcefully. For anyone who has played in a band, this statement is self-evident. Even if you sound-proof a band rehearsal room fairly well, neighbors and friends can still complain about the bass guitar and drums traveling through the sound insulation and walls.
Lower pitches (like drums and bass guitar) are able to travel through walls in this manner because they are better able to resonate physical matter at its resonant frequency, the rate of vibration at which it will tend to pulsate with greatest amplitude. It is this increased resonance effect that enhances the "driving," "innervating" effect of lower carrier frequencies on the brain when used with effective brainwave entrainment.
The Good News: Through daily use, the research indicates that most individuals’ brains can be trained to entrain to lower—and therefore more resonantly powerful—carrier frequencies.
For more answers to your questions on this subject, stay tuned for the next article: Carrier Wave Therapy in Brainwave Entrainment.