Recently I was fitted with custom ear mold
Starkey Phantoms. Very expensive, retail is $1,600. But I paid about half price thru my audiologist. They come with a 30 day trial period. I'm debating returning them...
My experience has not been what I hoped. They are adequate if you are on an active outdoor range and not shooting. When shooting, pressure from the cheek rest, at least in my case, changes the shape of my ear canal and allows more sound into my right ear. I ended up removing the Phantom from my right ear and used a good foam earplug.
I'm not confident that if someone is around a braked rifle that the Phantoms will offer enough hearing protection.
When shooting 9mm pistols on an outdoor range that had concrete walls on both the right and left side of the range, I had to double up and used the Phantoms with a set of electronic ear muffs. There was so much concussion bouncing off the concrete walls that the Phantoms alone were simply not enough.
Perhaps I should have them fitted again, this time as suggested, using a bite block and perhaps deeper into the ear canal.