Finger marks !!!
Actually you possibly won't hear them, they just look bad, as they lay on the surface.
That said you should never need to touch the playing surface anyway.
Slide you hand into the sleeve, support the record on your finger tips on the label, the outer edge then pushes against your palm. Bow the sleeve so it doesn't drag against the surface, and easy the prized piece of vinyl out. Then hold by outer edges, with two hands and place on platter. That way nothing touches the playing surface.
The above link was very good polomint, the bit about keeping the mat clean is very important.
Also I clean the "needle" after nearly every side, with a something that looks like a tiny tooth brush, just to flick the fluff ball off..... Then every few albums I drag a piece of "green stuff" across the diamond tip. It's a Linn recommended thing, it's actually something like 2 micron aluminum oxide linishing film !!! It removes the baked on deposits off the surface of the diamond.
Played a couple of records last night, one hasn't been out in over a year I guess, didn't need to clean it at all, and was near "Silent".....