I also hear a loud "gurgling" sound from the shower drain when I use the vanity or the kitchen sink. We've lived here 8 years and I can't recall if I've heard it before. I do know it was never as loud as it is now. The bathtub, vanity and kitchen sink were all put in by a professional plumber. The toilet which is directly connected to the same drain as the shower was put in by a handy man. There is currently a leak in the shower faucet (which I'm trying to read up on how to fix). I checked all of the escape valves I could find all were very clear and clean except for one. I cleaned it and now the water comming from all valves are very clear. Do you think I still need a snake?