Gus- thanks; that was interesting. I did go look up that beat thing but found a warning:

ATTENTION *
The following people should not use brainwaves entrainment applications like Binaural Beats Therapy :
People subject to any forms of seizures or epilepsy
People using pacemakers
People suffering from cardiac arrhythmia or other heart disorders
People taking stimulants, psychoactive drugs, or tranquilizers

I'm out :/
But I was ready to give it a try!!