Listening to: Nothing.
I went and participated in an obstacle this past weekend at Westminster Woods, which is a little north of Sebastopol. That's essentially considered the North Bay around these parts. There were many different "events" that consisted of both a physical and mental component: physical being climbing and balance and mental being jumping off high areas. This was the last event I participated in: Lion's Leap.
As you can see in the photo (rather, three put together), it's a 53 foot climb to a platform that ends on a wooden plank. The climb wasn't all too bad, to be honest. The worst part was finding some staples completely in the tree, thus unusable, or swaying too much on the cargo net. Some scraping did happen on my left shin from the net, but nothing worth showing people about.
In any case, it was one of the greatest experiences and it felt like I was in Assassin's Creed. I'll probably do it again next year, unless common sense catches up with me.