I really like how psychadedllic this is, *except*: you have to be careful about generating frequencies above 17kHz (yes I can still hear to 19khz despite being mid 50s); one of the high frequency bits in the 'background' becomes really foreground when it dials up to around 16kHz.
Funny story: had a guy come in, want to get a nice pair of PA speakers. Showed him QSC's (they're awesome); it was going great, then he went to his car and got his 'custom made' pre amp pedal for his guitar that "brightens everything up". As soon as he plugged it into the amp, I collapsed to the floor, covering my ears. They (the customer and my coworker, who's a drummer, who didn't believe in ear protection while drumming...) rushed to me and asked what's wrong
I said there's something squealing around the 20khz mark that is just insanely loud. Neither of them could hear it, my coworker said "maybe it's something you're hearing in your head?"
Right then a mother and child came in, and the kid collapsed to the ground covering his ears, and the mom also covered her ears and shouted in Mandarin "What the hell is that noise?".
At that point the customer immediately shut off the speaker, we tried again without his special pre-amp/ aural exciter (gotta love those guitar pedal names) and it was fine. We turned the volume down, plugged in his pre-amp without the guitar, same squeal (the kid who was in the store instantly covered his ears again, but didn't collapse to the floor this time) and I said "yup, I can hear the squeal, it's just quieter now.
The customer was dumbfounded. "So, you mean that 20KHz squeal is always there once I use that thing". Yup, I replied.
That's kind of why in the 50's and 60's, to avoid kids hanging around convenience stores, they'd use a high frequency tone generator.
Most men start losing the high frequencies after their 30s (we did a test in high school, and the physics teacher in his 30's could still hear everything up to 19khz, but the one in his late 50's couldn't hear anything above 11Khz!) because of listening to music too loudly, especially concerts and in-ear monitors (most women don't crank it up to the point of their ears bleeding) and when you start to lose hearing, it's from the top frequencies down.
I was very aware of this even in high school, so whenever our band wanted to go really loud, I said no. If your ears hurt, you're damaging them.
so just FYI you might want to filter out everything 16kHZ and above before posting, or just let your niece or nephew listen first and they'll tell you.
Mark