The sounds are sub strait born vibrations produced by the male spider and recorded using a lazer vibrometer, which translates vibrations into buzzing noises. It's these vibrations that travel through the ground that the female is listening to with her legs and with hairs on her legs, while she is watching the dance. And you mentioned a song and dance. Was that theoretical or no, they're actual yet? There's a couple of researchers that do this kind of work. An the one that does it on the the group that i work with, the paradise jumping spiders, is mostly damien elias and his lab. He has some vidios on you too.