building stuff, more stuff, and a little bit of… stuff
Half of the Flanagan “Neurophone” circuitry is devoted to pretending the signal was sent as electromagnetic radiation. The double-differentiator section just mimics what an antenna does.
If you’re looking to “train your brain,” it might be easier to simplify things a little. Instead of using lots of circuitry to pretend an antenna was involved, get a real one in play.
Plug a pink noise generator into a low-power audio amplifier driving a coil of wire on the floor around you. Put a small speaker in series with the wire coil. Total parts cost? Really cheap!
This will create pink noise as both electromagnetic waves and acoustic ones. If my understanding of “Neurophone” operation is correct, this should produce the same effects on the brain. Your brain should see the electromagnetic waves in a very similar way to a pink noise signal from a “Neurophone,” though much more weakly. This means any effects might take weeks or months to appear, instead of days or weeks.
Why bother? The “Neurophone” is supposed to massively boost IQ — and there are rumors on the Internet that it can do even more extraordinary things.