From Learning English, this is the Technology Report.
A fly with an extremely unusual ability to hear is the model for what may be the future of new and improved hearing aids. The insect behaves like a parasite -- an organism that lives on or in another organism called a host. This exceptional fly places larvae -- a young fly onto a cricket host. The larvae digs into the cricket and eats the insect from the inside out.
The tiny yellow fly lives in Central America and the southern United States. It finds its host by listening for the crickets high chirping voice. The fly can easily find a cricket from as far away as 91 meters.
Neal Hall is a sound engineer who worked on the new hearing aid model. He says the flys behavior is very strange. Mr. Hall and his team at the University of Texas made a copy of the flys hearing structure.
And they discovered that the fly has a clever mechanism that instead of using two independent ears, like a human would, the flys ears are actually coupled, says Hall.
The flys ears are two millimeters apart. That distance is so small, that sound reaches one ear just four millionths of a second before arriving at the other. Experts say it should be impossible to identify where a sound is coming from. But inside this flys ear is a 1.5 millimeters long structure similar to a see-saw -- a piece of childrens party equipment.
Like the see-saw, the flys ear structure goes up and down from a central point. Pressure waves against the structure increase the time it takes for sound to travel and permit the fly to find its host.
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