I love it when ads use a negative situation to advertise their product.  It's such a backwards way of promoting something.  Directly this ad is saying, use our headphones and you'll die because you won't hear the waterfall you're about fly off of.  Obviously Bose doesn't literally want people to die becasue they won't hear something dangerous coming.  However, the point of the ad is to demonstrate in an unexpected way that these are great noise-cancelling headphones.  It would be obvious, boring and expected to show someone wearing the headphones and smiling serenely while an obnoxious person is trying to talk to them, or if they were in a crowded, noisy waiting room.  Bose is giving the audience a break from the expected, and letting them enjoy the ad rather than just seeing it.  As I said, I just really enjoy ads when they come up with an outside-of-the-box way to demonstrate the benefits of a product.  This ad is actually showcasing the main benefit of the product as a bad thing--a dangerous thing even.  It's a more intelligent way to approach showcasing a benefit and I appreciate it because most ads are not so considerate to the bored audience that is the American consumer.