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Homework Help: Intensity/ sound level

  1. Apr 26, 2008 #1
    1. The problem statement, all variables and given/known data

    The average sound level of a typical musical instrument in a musical group is B dB. WHat is the sound level in Db if 10 instruments are simultaneously playing.

    answer choices: B'= 10B, 5B, B+5, B+20, B+2, B+10, B+1, 20B, B, or 2B

    My first thought was that it would be 10B since each instrument would contribute a sound level of B. My logic seems too simple. Can someone tell me if I'm on the right path? thanks.
  2. jcsd
  3. Apr 26, 2008 #2


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    Homework Helper

    Hi glasshut137,

    When you have multiple sound sources, the total sound level in dB does not add (so two 10dB sources do not give a sound level of 20dB). Instead it is the intensity of the sound that adds together.

    You should have an expression that relates sound level in dB and sound intensity so that you can convert from one to the other and back. What do you get?
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