This may come as a surprise to you, but most flies don't have the ability to hear. However, certain parasitic flies have a hearing system that is so exact in pinpointing a sound's origin that it rivals the exceptional ears of owls and cats.
This fly's superb hearing surprised scientists because its tiny body is too small to use the same kind of hearing system that larger animals use. And yet they discovered that the fly was using its hearing to locate the chirps of crickets in order to then deposit parasitic larvae onto the crickets' bodies.
What they found was unlike any other known ear structure, this fly's eardrums are connected by a bridge of stiff material. Vibrations that travel between the two eardrums enable the fly to pinpoint the origin of a sound as accurately as any other sound system we know of.
And what's more, this fly's exceptional hearing system is influencing microphone and hearing aid technology. For instance, it could lead to hearing aids that hide within a person's ear canal and yet are able to gather sound primarily from the direction the listener is facing.