This is Audiograph — the Bay Area’s sonic signature. Each week, we’ll play you a sound recorded somewhere in the Bay Area. Your job? Listen to the sound in the player above, figure out where it was recorded and what it is, then call to let us know. If you think you can identify this Audiograph sound of the week, call 415-264-7106. Also, tell us where to record next. We’ll give away a KALW t-shirt every week to one lucky caller. We will announce the winner of this week's sound on Thursday during the 5 p.m. broadcast of Crosscurrents . This auditory guessing game is part of our project, Audiograph, a crowd-sourced collaborative radio project mapping the sonic signature of each of the Bay Area’s nine counties. By using the sounds of voices, nature, industry, and music, Audiograph tells the story of where you live, and the people who live there with you.