Loudness Calculation based on distance and project acoustics data

I have to calculate the loudness of sound that the player is hearing based on distance, like if the player is far away and within a fall of distance, he will hear less loud sound, and if he is in the inner radiushe will hear more loud sound but problem is my map is baked using project acoustics, due to which loudness will also vary based on this project acoustics data. How can I calculate loudness based on distance by considering project acoustics too?