The difference of sound levels between two points is 30 dB. The ratio of pressure amplitude between the two points is

Here L1=10log10⁡I1I0 and L2=10log10⁡I2I0 ΔL=L2−L1=10log10⁡I2I1=10log10⁡P2P12 ∵I∝P2  Now 30=20log10⁡P2P1 or 32=log10⁡P2P1 or P2P1=(10)3/2−(1000)=31⋅62≈32