1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?