I use EarPeace HD, theres other companies offering similar to what these guys do but these are the ones i own.
love them, instead of blocking soundwaves reaching your ear to make it quieter, as you mention above, they actually block the ear and then allow sound to pass through the filter which in turn basically just turns the volume down yet you still get the clarity, thats a dumbed down version of whats happening, but hopefully shows the difference. You can get different filters for them for different volumes too, come in a handy carry case which does bulk my keys up but not too much! Strongly recommend them/this style, i dont really think you need moulded in ears… but i havnt tried 🙂 if this is your profession and will be for the next 20 years, maybe its worth the investment!