Formula:
The total sound pressure level (Ltotal) from multiple incoherent sound sources is calculated using the following formula:
Ltotal = 10 × log10 ( Σ 10(Li / 10) )
Where:
- Ltotal = The total combined sound level in decibels (dB).
- Li = The decibel level of each individual sound source.
- Σ = The summation symbol, meaning you add up all the values for 10(Li / 10).
- log10 = The base-10 logarithm.
This formula accounts for the logarithmic nature of the decibel scale, meaning sound levels do not simply add arithmetically.