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Decibel Comparison Problem

  1. Sep 26, 2007 #1
    Hello everyone,

    Could anyone please show me the appropriate formulas which I need for the following question?

    1. How many times louder or softer than sound level of 40 dB is a sound at

    a) 68 dB? b) 0.3 dB?

    Thank you.
  2. jcsd
  3. Sep 26, 2007 #2


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    Staff: Mentor

  4. Sep 26, 2007 #3
    Thanks for your reply.

    I know how to calculate the difference in sound level for integers divisible by 10. For example, 60 dB is 10^2 or 100 times louder than 40 dB.

    However, I know that I must use logarithms for calculating the difference in sound level for all other integers.
  5. Sep 26, 2007 #4


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    Staff: Mentor

    Well look at the example of 40 dB

    I = 10000 I0, or I = [tex]10^{40dB/10}[/tex] I0 = 10000 I0

    and for 60 dB, I = [tex]10^{60dB/10}[/tex] I0 = 106I0

    and for 68 dB, ____________?
  6. Oct 3, 2007 #5
    Thank you very much for your help!
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