A Fly on the Wall, Literally

The secret to better hearing-aid technology may lie in the super hearing abilities of parasitic flies, say researchers at the University of Toronto and Cornell University. While most flies have no sense of hearing at all, the tiny Ormia ochracea – which is less than one centimetre long – can determine the direction of a sound within a range of two degrees, a feat previously ascribed to only keen-eared owls, cats and humans. “Their sense of hearing is remarkable considering their ears are so close together – this trait would make directional hearing impossible in any other animal,” says zoology professor Andrew Mason of the U of T at Scarborough’s division of life sciences and lead author of the study that appeared in the April 5 issue of Nature. Hearing aids that incorporate directional microphones could help hearing-impaired people filter out background noise and tune in to one sound.