Another picture for ya...this is part of my 3/4 bath. That is a vanity drain on left and a shower drain on the right (toilet drain not shown in this pic). Above the floor the vanity drain has a dry vent. The shower drain drops about 30" to the trap. I poured a cup of water in the shower pan and I think my neighbor could hear the water dropping into the trap from across the street. This is going to drive me nuts. What should be done here?