How do you find the “bad” seeds in the bunch? According to Thomas Pearson, a scientist with the Agricultural Research Service, you listen very closely.

Pearson — who's an agricultural engineer at the agency's Grain Marketing and Production Research Center in Manhattan, Kan. — has developed an acoustics-based sorter that can distinguish between “clean” wheat kernels and those that have been nibbled on and spoiled by insects.

The idea behind the novel technology is simple: A wheat kernel that's whole and intact will make a slightly different, high-pitched “ping” when striking a steel plate than the sound made by a kernel that's been tunneled through by an insect.

Because individual kernels are so small, lightweight and hard, any acoustic energy they emit is inaudible to human ears. So, Pearson made sure to outfit his sorting system with a special microphone that can pick up ultra-sonic sounds at exceptionally high frequencies.

The technology — which would undoubtedly lead to more accurate estimates of insect damage in wheat loads — is now ready for a private-sector partner to help bring it to market. ARS is the U.S. Department of Agriculture's chief, scientific research agency.