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These animals can hear everything - Jakob Christensen-Dalsgaard

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TEDEd Animation

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The world is always abuzz with sounds, many of which human ears simply can’t hear. However, other species have extraordinary adaptations that grant them access to realms of sonic extremes. And some of them don’t even have ears— at least, not like we typically imagine. So, which is the best listener? Jakob Christensen-Dalsgaard explores the auditory capabilities of the animal kingdom.

Objects, like the prey of bats and dolphins, reflect sound when their size is approximately comparable to or larger than the wavelength of sound. The relationship between wavelength w and frequency f is w=c/f, where c is the speed of sound. The speed of sound in air is approximately 340 m/s, and the speed of sound in water is approximately 1500 m/s. Using the relationship between frequency and wavelength, what is the approximate size of prey that a bat with echolocation frequency of 34000 Hz can detect? What size of prey would be detectable for a toothed whale, echolocating in water at the same frequency?

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Meet The Creators

  • Educator Jakob Christensen-Dalsgaard
  • Director Joseph Clark
  • Narrator Jack Cutmore-Scott
  • Music Jarrett Farkas
  • Sound Designer and Mixer Weston Fonger
  • Director of Production Gerta Xhelo
  • Producer Sazia Afrin
  • Editorial Director Alex Rosenthal
  • Editorial Producer Cella Wright
  • Script Editor Emma Bryce
  • Fact-Checker Charles Wallace

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