I recall seeing a video of a guy with a decibel meter on their expensive-ass phone and attempted to get readings out of an unsuppressed .45acp and then again with an FTN4 installed. It went from ~149 decibels to ~125 or something very close to that.

In the end, the FTN4 brought it down into a range that was hearing safe for a few shots. For comparison, the same firearm with a popular standard-baffle commercial suppressor wasn’t able to do much better than the FTN.

Hope that helps!