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Why do we only hear between 20Hz and 20khz

  1. Oct 20, 2012 #1


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    i no that the frequency range limits are determined by the cochlea where the low frequency sounds are localized on one terminal and the high frequency on the second end, but i am wondering if there exist a formula that permits to calculate these ranges analytically
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  3. Oct 21, 2012 #2


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    Although your brain cannot hear frequencies below about 20 Hz there is evidence that the structures of the ear respond to much lower frequencies - for example when driving up/down a hill we can detect exceptionally low frequency pressure changes caused by changes in altitude.

    Some fields of science use very low frequencies to bias structures in the ear...


  4. Oct 21, 2012 #3


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    One reason for the lower limit to hearing must surely be that it gets progressively harder to 'match' the impedance of a small diaphragm like the eardrum to the impedance inherent in the hairs of the cochlea.
    Another reason could be simply that evolution has made our hearing range 'just good enough' to function adequately as an organism - as with pretty much every one of our senses and abilities. Cost-benefit analysis rules.

    We all know that Elephants have big ears - but that's because Noddy won't pay the ransom. Boom boom.
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