Bull Roarer Experiments

i experimented with two different sizes of bull roarers that I have recently made. What is a "Bull Roarer?" you ask. It is an ancient instrument that creates a sound, much of which is below the human range of hearing...more down there with whales...but which can affect our brains without a conscious level of hearing. BullRoarers have been used to for long distance signaling, for scaring the bejezess out of superstiious people, for altering your brain waves, or, of course, for rounding up whales. You should try this at home. Might be useful for decapitating dandilions when gathering them for making dandilion wine. But watch out for your brain.