Perhaps I should have labeled it author-ultrasonic ;) I haven't really found much data about the distribution of hearing capacities, so it's hard to tune this

Perhaps I should have labeled it author-ultrasonic ;) I haven't really found much data about the distribution of hearing capacities, so it's hard to tune this to be truly ultrasonic. The average sound equipment starts getting really distorted at around 19kHz, which doesn't leave much space above 17,5, unfortunately. Thanks for trying my demo!