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An insect with an extremely unusual ability to hear is the model for what may be the future of hearing aids. The insect, a fly, behaves like a parasite, an organism that lives on or in another organism called a host. This exceptional fly places larva, a young fly, onto a cricket host. The larva digs into the cricket and eats the insect from the inside out. The yellow fly is native to Central America and the southern United States. It finds its larva host by listening for the cricket’s sound. The fly’s strong sense of hearing can direct it to a cricket even 100 meters away. But the insect’s ears are just two millimeters apart. That is so close that sound should reach each ear at almost the same moment. This would make it difficult to find where a sound came from. But, the fly also has a tiny structure between its ears that creates pressure to slow down the sound waves. This permits the fly to identify where the sound came from. Neal Hall is a sound engineer at the University of Texas. He and his team of researchers created an electronic hearing device. The team made a silicon copy of the fly’s ear structures. They used materials that can turn mechanical pressure into electricity. The device requires little power as a result. This means it would be less costly to use. Mr. Hall says the device could improve hearing aids in the future. He says it also could have military and defense uses. But he says more research and development work is required. In July, the journal Applied Physics Letters published a report about the University of Texas research.