By "operated", do you mean when reclined or otherwise repositioned, as opposed to simply when someone is squirming while seated?
If so, the noise must be coming from the adjustment mechanism somewhere, and presumably could be eliminated by proper lubrication or adjustment or rebuilding with better bearings/pivots or something along those lines. Personally, I'd just live with it, since fixing seems like it's probably a lot of effort with disassembly and analysis and so forth.
