Very unhappy with paying 20 dollars for these things. You must push them very far into your ear, to the point where it becomes uncomfortable, and if you don't have a proper amount of earwax, you're just not going to get a good seal. And the only time it does form a properly good seal, there's an uncomfortable vacuum effect on your inner ear. Any movement of the head or jaw will dislodge them from their sealed state. I haven't used these at a...