A parasitic fly may revolutionize hearing aid technology. Cornell's Chronicle reports how researchers there and elsewhere have found the Ormia ochracea fly has amazingly acute hearing, able to detect the location of a sound within two degrees. Heretofore such acuity was thought possible only in large creatures like humans, whose ears can be placed many centimeters apart, but these flies' entire bodies are smaller than the smallest hearing aids today. University of Illinois at Urbana Champaign's neuroethology department has a whole webpage on the phenomenon, which says "the whole organ is less than 2mm wide." The page also describes how the flies' ears work, and has more real information than anywhere else online. Why is directional hearing important? Because most hearing aids today amplify all sound--background noise as well as the conversation you're trying to listen to. Using directional information could help hearing aids screen out background noise and only amplify what the user wants to hear. Researchers at Georgia Tech are working on early stages of building devices that work like the fly's ear.