News release: “Outside, the global position system allows mobile phone users to pinpoint their location with surprising accuracy. But indoors, those who are lost are out of luck: GPS satellite signals can’t penetrate roofs. Researchers at the McCormick School of Engineering and Applied Science have determined one way of figuring out your location inside: by letting your phone listen. Their new mobile phone app, called Batphone, allows users to record ambient noise in a room and tag it with an acoustic fingerprint, which allows future users to use that database of fingerprints to determine their location.” “We have found that the app has been very successful in determining locations,” says app developer Stephen Tarzia, a computer engineering graduate student in the Empathic Systems Project headed by electrical engineering and computer science professors Peter Dinda and Gokhan Memik and adjunct professor Robert Dick.”