Inserting the formulas ( p i p 0 ) 2 = 10 L i 10 dB , i = 1 , 2 , … … , n in the formula for the sum of the sound pressure levels yields L Σ Σ = 10 log 10 ⁡ ⁡ ( 10 L 1 10 dB + 10 L 2 10 dB + ⋯ ⋯ + 10 L n 10 dB ) dB .