Sound Pressure Level

The sound pressure level $\text{SPL}$ is determined at the receiver position by calculating, for each octave band $i$, the average of the complex pressure $\bar{p}_{i}$ across the band:

$$\text{SPL}_{i} = 20 \log_{10}\left (\frac{\bar{p}_{i}}{p_0}\right ) ,$$

where the reference pressure $p_0$ is 20 μPa.