Neopixel power line feedback phenomena

While working on a christmas gift for a friend I encountered an interesting phenomena involving signal leakage over the USB power line.  The USB to UART adaptor I was using caused the signal leakage to go into the USB hub of the keyboard and into the amplifier for my headphones which amplified the signal up to an audible level. It sounds rather ethereal in my opinion with the echo fading similarly to a Meteor echo radio reflection. The program that was running at the time was a generic randomization "twinkle"program which pulsed on a random pixel, color and fade time on the strip.