With their very sharp ears, bats can handle themselves pretty well and look for food even in the pitch-black darkness. By clearly distinguishing one echo from another, they are able to navigate through the night. But how do they do it? Scientists from Brown University may have figured it out. They refer to it as frequency hopping, which involves focusing on the echoes’ lowest frequencies.
And it has potential, neuroscientist James Simmons and colleagues suggest in a paper in the journal Proceedings of the National Academy of Sciences.
“By incorporating this feature into an existing auditory model of FM biosonar, the model can reject echoes that lack the lowest frequencies in the most recent broadcast, thus suppressing echoes of an earlier broadcast that has slightly higher low-end frequencies,” they write.
Bats locate objects by emitting ultrasonic sounds called broadcasts, which contain frequencies ranging from 25 kHz to 110 kHz, and listening to the returning echoes.
Occasionally, an initial broadcast elicits a long-delay echo reflected from a distant object, and a closely successive broadcast triggers a short-delay echo from a nearby object. They reach the bat’s ears at about the same time, but the bat deals with the potential ambiguity in matching the echo to the correct broadcast.
It’s just amazing how bats can do this quickly.
More details about this study over at Cosmos Magazine.
(Image Credit: BatLab/ Cosmos Magazine)