Did some research here and found this to be a popular option so I picked some up:
I use these when I'm jamming alone or along with a song that's amplified in the studio.
I can tell that the volume level has dropped when I use them, and the frequency ranges are still somewhat clear. Almost too clear that I wonder if they actually are helping?
What do you all use nowadays if you're playing alone?
*These are the Etymotic ER20's