Why wont you be allowed to have your iphone with you?
they usually put the wires up in a ponytail with your hair, so it kind of feels like a pony tail, just a bit heavier and longer strains of hair.
I think after the first 10 minutes of having it on, i didn't feel any diffrence besides the weight from them, making my ponytail seeming full of heavier/thicker hair.

Have they not specified to stay awake during certain times prior to the testing? before my sleep study, they had me have approx 3 hours of sleep then i had to stay awake from 4am- the testing time, which was that following night.. and i was having troubles not sleeping even with being loaded up on caffiene and sugar and my stimulant med. by the time the sleep study came, i crashed. and the bed was soooo comfy!