You're talking about the dust cover in the center? Use a vacuum cleaner an have your finger on the switch, and set the "vent", open on the hose a bit.
OR use a piece of tape, I've never seen one I couldn't pull out or repair.
Even cracked, I've repaired them with nail polish, and or silicone.
Also pretty easy to replace just the dust cover. You have to get a size that will work..
The noise, usually means something is touching. Pushing in the dust cover? Not sure why it would make noise. Not usually a problem, other than looking bad. It can offer distortion, but I'd doubt I could hear the difference.. Maybe, but I'd doubt it..
Regards