We moved into a house last year that is on a somewhat busy street and traffic noise is an issue.

We learned after moving in that the walls had zero insulation so we blew in cellulose but that didn’t help much.

I’m planning to add a layer of 5/8” drywall to the rooms facing the street and I was going to use Green Glue but I’m seeing a lot of recommendations for MLV and Sonopan but also seeing mixed reviews about which is superior.

I’d even combine them, though I understand Green Glue does not adhere to MLV.

This video argues that Sonopan and Green Glue are equally effective: https://m.youtube.com/watch?v=SiqEvlAomvI

This website says Sonopan is better: https://soundproofguide.com/sonopan-what-where-and-does-it-work-for-soundproofing/

Do you have any insights about which of these three approaches—or combinations of them—you’d recommend?

Would really appreciate any insights!