I had a tour at the Louvre Abu Dhabi a few days ago with a larger group, and they brought their own "whisper system". It was the first time for me using one of these - what a game changer!
Each guests have their own ear-piece, I wore this headset and then we all tuned in to the same channel. Then I could talk in my normal voice, and they could all hear me, even if they were a few meters away. Well, apparently it stretched up to 50 meters - so I could probably have been having a coffee in the café and still guided them through..!
I did feel a little bit like a fast food drive-through operator, but looks aside - such a different experience with a big group, SO much easier!
Being a gadget girl, I almost wanted to buy a whole system for myself to use for other groups as well, ha ha! Maybe for next season!