Dampers are delicious quick-breads cooked over a campfire or in a Dutch oven…
The word also refers to devices which pull, negate, or otherwise interfere with psionic signals. The device could be a Shield, but more often the word implies something with more substance.
For example, for some people a good solid piece of hematite (an iron ore) causes a sedating effect and cuts down on incoming telepathic and empathic signals when worn or held against the skin. It can also produce a disorienting effect, and cause weird “burning” sensations. I strongly suggest not driving while using one.
Shields are shiny. Having a Plan B is even shinier.
Hematite was the crystal that convinced me to take crystals seriously. I’d pooh-poohed most crystal stuff until one day I happened to pick up a hematite, and it pulled so much out of me that I staggered. It was kind of cool…in a startling, what-the-fluff kind of way.
For other people, hematite produces no effect at all.
Some people find that amber and/or onyx do the same thing.
If you wish to experiment with this, I suggest starting with hematite. It is cheap and fairly easy to get. By “cheap”, I mean you can sometimes find the stuff in gumball machines for a quarter. “Magnetic hematite” is not the same substance, but feel free to try it, too.