Remember when Ridley Scott asked people to record videos to be compiled into the Life in a Day movie? Bryan Pijanowski, Purdue University's Soundscape ecologist, wants to repeat the task today, but with audio rather than video. He's developed the Soundscape Recorder app for iOS and Android and is asking people to suck down three minutes of ambient noise to help measure the changes to the sonic environment. Once you've recorded your moment, you'll be asked to describe what you heard and how it made you feel -- something that Pijanowski hopes will become an annual event every Earth Day. Just don't follow our example and try and record the ambience of an empty room, because that's not helping.