Just a heads up, you can buy a pair of frequency-neutral earplugs for about $10-$15. They reduce the volume without giving the sound that "underwater" quality.

Just a heads up, you can buy a pair of frequency-neutral earplugs for about $10-$15. They reduce the volume without giving the sound that "underwater" quality. The only downside is that they aren't disposable, so you might need to wash them with a damp paper towel between uses.