Im impressed by how they work independently as well as a pair. She wears them everyday! Purchased for my granddaughter for Christmas. You can definitely hear it at least 1 room away! I can feel my self sweat shortly after putting it on. Disappointed that only 2 straps are truly adjustable, the middle strap is permanently attached to the center strap. It cannot, I spent hours of my time researching and every method is very poorly explained and it will not give you exact instructions how. The battery life has been great also, I?ve not run them out on a single use yet. The sound in general was very good. It easily forced that vile liquid down my gullet.