We use locally made silencers for the equipment cooling exhaust on the A320 and 737's, reduces the noise in the hangar significantly.
Can I have that pic as well, Fargoo ?
Earmuffs are always better than earplugs for the simple reason that they are more hygienic.
On a sidenote, I always advice ppl to not wear their earmuffs totally covering their ears that it's working 100% efficiently. I once almost walked right in front of an engine during an EGR simply because of the fact that I couldn't hear it. It was my first time wearing an ear muff and I mistook the engine noise for the packs.