It is a question. His first language was obviously not english, so be understanding. I think that delta waves are the deep sleep waves, so if they dont put you to sleep, they will probably make you very relaxed.
When I listen to delta beats they make me very very relaxed and I fall into a trance-like state with lots of dreamlike visuals, this would probably be a good tone to induce a WILD. It'll make you fall asleep if you don't make an effort to keep yourself awake.
