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Medical Psychophysics: Decibels

  1. Sep 25, 2005 #1
    I don't understand the math of the 10 fold system.
    Could someone go into detail of it for me?

    I just don't see how that works.

    10 db = 100
    20 = 1000
    30 = 10000?

    i don't understand the system here.
     
  2. jcsd
  3. Sep 25, 2005 #2
    It's a log scale

    [tex]
    I(db) = 10*log_{10}(\frac{I}{I_0})
    [/tex]

    For example

    [tex]
    10db = 10*log_{10}(10)
    [/tex]

    [tex]
    30db = 10*log_{10}(1000)
    [/tex]


    [tex]
    60db = 10*log_{10}(1000000)
    [/tex]
     
  4. Sep 25, 2005 #3
    I don't understand that log stuff or I think I'd have this understood by now.

    ==update==
    Ah, I understand it a bit better now after doing some math work. Thank you.

    simply the 6 part of 60 could signify 6 zeros after the 1, making it 1 million.
     
    Last edited: Sep 25, 2005
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