How much acoustic power enters the window via the sound waves?

Question

A window whose area is 1 m² opens on a street where the street noise results in an intensity level at the window of 60 dB. How much acoustic power enters the window via the sound waves?

Answer 1

Sound Intensity Level in dB is, β = 10 log (I/I₀)

Here, β = 60 dB

I₀ = 10^-12 W/m² is the Reference level.

Solving for I:

β/10 = log (I/I₀)

I/I₀ = 10^(β/10)

I = 10^(β/10) I₀ = (10⁶) (10^-12) W/m² = 10^-6 W/m²

Since I = P/A,

P = IA = (10^-6 W/m²) (1m²) = 10^-6 W or 1 μW