Q) Two friends are walking, having a normal conversation; the sound level of the conversation if 60 dB. When they get near a busy street, they have to double the intensity of the sound to be able to hear each other. Calculate the new sound level.
I used the formula: L=10log(I/Io)
Then: 120 = 10log(I/10^-12)
Is that correct?
120dB is the level you might experience at a rock concert!
You need to double the I value:
L = 10log(2*I/Io)
L = 10log(I/Io) + 10log(2) → 60 + 3.01 ≈ 63dB
Remember, Julius, that
log ( a * b) = log a + log b
Let a = I/I0 and Let b = 2
L = 10 log [ (2 I / I0 ) ] =
10 [ log [ I / I0 * 2 ] ] = distribute the 10 over the above log property
10log (I / I0) + 10log (2) =
60 + 3.01 ≈