Echolocation: SEEING WITH EARS

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SEEING WITH EARS

• Presented By
• Ravikash Maurya
• (14484sc038)
• Banaras Hindu University, Varanasi

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• This ppt was prepared for
• Seminar presentation purpose in M.Sc. semester
  IV
• In
• Department of Zoology
• Institute of Science
• Banaras Hindu University (BHU)
• Varanasi (India).

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How to see with Ears??

• This could be achieved by listening
  interpreting of a sound coming from an object.
• Ears are adopter of sound(signal)
• Brain is interpreter of signal.
• This property is known as Echolocation.
• (Discovered by Griffin in 1938)
• A new trending term is Biosonar.

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• An Echo is a reflection of sound after hitting an
  object.

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What is Echolocation?

• "Echolocation is a property of using echo to
  determine where objects are in space
• In other words, with the help of echoes, the
  brain draw an image of the objects.

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Echolocation Is Used by Animals

• There are some animals who have developed
  property to Echo-locate objects without help of
  vision.
• The property of echolocation is well developed in
  mammals.

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Echolocating Animals
Bats
Whales
Dolphins

• Echolocation is Only found in Microchiropteran
  bats

• Echolocation helps Whales to navigate where
  vision is extremely
• limited in range due to Absorption or
• Turbidity.

• Dolphins habitats have low visibility due to
  dirty water Turbidity. Echolocation help them
  for foraging.

• Echolocation help them for navigation foraging
  in total darkness.

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How do Animals echolocate??

• The echolocating animals cry loud so that their
  sound become Echo after hitting the target.

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Principle Of Echolocation

• Echo locating bats emit sound
• Pulses(Clicks) of very high frequency and listen
  for returning echoes to form an auditory scene..

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What a bat can detect by using echolocation

• Distance(Range)- by comparing the time of emitted
  pulse to the time of the returning Echo.
• Size- larger animals reflect more sound(high
  intensity) and smaller animal reflect less sound
  (low intensity).
• Movement- by comparing amount of echo obtained
  on Left Right ear.
• Velocity- by taking advantage of Doppler Shift.
• Echo of higher frequency Target is gaining.
• Echo of lower frequency Target is outstanding.

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Phases Sequence of Echolocation
There are 4 steps in Prey capturing by bats- 1-
Search 2- Approach 3-Track 4-Capture
Redrawn From Simmons Kick(1984)
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(No Transcript)
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You should not forget that echoes of other bats
in a space create a noise. Then, how a bat
recognize its own voice in noise? The JAR
solves this problem.
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Experimental Evidence of JAR
Reference Gillam E.H. et al. Rapid jamming
avoidance in biosonar. Proc. R. Soc. B 274,
651660 (2007)
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Co-evolution of Bat Prey

• With the evolution of Echolocation in bat, their
  Prey has also been evolved.
• Some important evolved escaping property of Prey
  are-
• By interfering Bats Sonar System (eg. Tiger
  Moth).
• By flying in irregular pattern.
• By becoming just quiet.
• By having hairy wings.

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Convergent Evolution Of Echolocation

• Reference Parker et al. Genome-wide signatures
  of convergent evolution in echolocating mammals.
  Nature 502, 228-236(2013).

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Learning From Nature

• Many equipment have been developed using the clue
  of Natural Echolocation .
• Examples of Some
• Echo-locating
• Inventions
• All these equipment produce ultrasounds for
  echolocation .

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Radar

• RAdio Detection And Ranging
• It is similar to bats, used for Arial
  echolocation.
• Radar  uses Radio wave or Microwave to determine
  the range, angle, or velocity of objects.

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Sonar

• Sound Navigation And  Ranging
• Similar to Dolphins, used for Underwater
  echolocation.
• It uses ultrasound to navigate.

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Driverless Car

• It uses Radar for navigation.

Downloaded from Google official Blog
(https//goo.gl/wYhSl2)
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Tactic Devices for Blinds
Downloaded from PhysOrg.com (http//goo.gl/Pura08
)
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Ben Underwood The Superman

• Descriptions

• Name Ben Underwood
• Life 1992-2009 (17 Years Only)
• Location California (USA)
• Handicapped Yes. His eyes were removed during
  operation of Retinoblastoma (a Retinal Cancer)
• Special Property Ben used to echolocate the
  surrounding by producing Click Sounds (With His
  Tongue). He was able to locate buildings,
  playing football, riding bike etc.
• Death When same cancer returned.
• Tribute His Mom wrote a book about Him-Echoes
  of an Angel.
• Website www.Benunderwood.com

vDownloaded From Benunderwood.com
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Blind men teach themselves to see with Ears
Downloaded from-http//goo.gl/hOkcmk
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References

• Chiu C., Xian W., Moss C.F. Flying in silence
  Echolocating bats cease vocalizing to avoid sonar
  jamming. PNAS 105, 1311613121(2008).
• Gillam E.H., Ulanovsky N., McCracken G.F. Rapid
  jamming avoidance in biosonar. Proc. R. Soc. B
  274, 651660 (2007) .
• Jones G, Siemers B.M. The communicative potential
  of bat echolocation pulses. Journal of
  Comparative Physiology A 197(5), 447-457(2011).
• Knornschild M., Jung K., Nagy M.,Metz M.,Kalko
  E. Bat echolocation calls facilitate social
  communication. Proc. R. Soc. B 279,
  48274835(2012) .
• Madsen P. T., Surlykke A. Functional Convergence
  in Bat and Toothed Whale Biosonars. Physiology
  28, 276283(2013).
• Parker J., Tsagkogeorga G., Cotton J.A., Liu Y.,
  Provero P., Stupka E., Rossiter S.J. Genome-wide
  signatures of convergent evolution in
  echolocating mammals. Nature 502, 228-236(2013).
• Shnitzler H.U., Kalko E.K.V. Echolocation by
  insect-eating bats. BioScience 51, 557-569(2001).
• Surlykke A, Kalko E.K.V. Echolocating Bats Cry
  Out Loud to Detect Their Prey. PLoS ONE 3(4),
  1-10(2008).
• Whitelow W. L. Au, Simmon J. A. Echolocation in
  Dolphins and Bats,
  Physics Today, 40-45(2007).

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• Thanking You..