One of the by-products of life in a big city is a near constant cacophony of sounds. Sometimes it can be difficult to hone in on a beautiful aural moment. And a lot of us wear headphones and ear buds to drown it all out. But Eric Leonardson wants you to listen very, very closely to the urban soundtrack. He’s the co-chair of the Midwest Society for Acoustic Ecology, a group that among other things, organizes so-called “Sound Walks” around Chicagoland. This Saturday, Leonardson will lead a Sound Walk at the Pullman National Monument, starting at the historic Pullman factory clock tower and weaving through a mix of urban and natural environments — listening all the way. (Flickr/Ron Cogswell)