Question

Two speakers are both emitting sounds, the first with an intensity level of 1 x 10^{-11} \frac{W}{m^2} and the second with an intensity of 1 x 10^{-8} \frac{W}{m^2}.

What is the db level of the first?
\beta =

What is the difference in the decibel (db) level of the two sounds?
\Delta \beta =

Answer 1

db1 = 10*Log(I/Io)
db1 = 10*Log(10^(-11)/10^(-12) =
10*Log(10^(-11)*10^12) = 10*Log(10) =
10*1 = 10.

db2 = 10*Log(10^(-8)/10^(-12) =
10*Log(10^(-8)*10^12) = 10*Log(10^4) =
10 * 4 = 40.

40 - 10 = 30db Difference.