There are very few times in my life when I experience silence. There is the ever-present ambient noise of the city or the office: traffic, planes, power mowers, power tools, the intrusive alerts from computers signaling new emails or texts, ringtones. I find myself obsessively plugged in to the news, Twitter and YouTube—all available all the time, portable and near at hand on my cellphone.
And then there is the noise in my head: racing thoughts, internal conversations, grocery lists, music. Even—or perhaps especially—when the world around me is mostly still, I notice that I am not...