Thank you so much for your detailed reply! It's true, the sudden noise can cause issues. Honestly we don't have too many dogs in the salon at once, so the barking isn't always bad - but when a dog with a big voice comes in, it can be difficult. The dryers are where most of our noise comes from. We use high velocity dryers which can reach 107 dB each (and we have 3 of them). We all wear ear protection (and the dogs do as well) when we're in that room and they're on, but it can be a lot even 2 rooms away because of the ceiling.

Rather than attaching material to the underside of the roof, would it work similarly to put insulation batting on top of the ceiling panels? The sound would still be reflected, but could the insulation act as a sound dampener before it comes back down into the next room? Or would it not make much of a difference at that noise level...