Most quoted sound levels for suppressors are for shots recorded at the muzzle. With that in mind, what is the difference when you head downrange?
To answer that, Tim Harmsen with the Military Arms Channel does a really interesting experiment where he (don’t try this at home) takes shelter behind a plate of AR400 grade steel with a meter while his buddy takes shots with an AR at various ranges at a target 25 yards to his side.
Using Winchester white box 5.56mm, they run it unsuppressed and with two different cans (a SiCo Specwar and an OSS Helix-QD) from 25 yards and follow it up out to 400 yards, contrasting the readings in real time. If you have sound propagation questions (remember the sonic boom of the bullet itself) then this is your video.