One other interesting point that could come up but wasn't in the calculations is the reflection of the sound of the toilet tank lid hitting the tank. Most toil

One other interesting point that could come up but wasn't in the calculations is the reflection of the sound of the toilet tank lid hitting the tank. Most toilets are put into little nooks with just a few open inches between the toilet and the wall it backs up to, and maybe a foot on either side of the toilet, making a little alcove. Sound will reflect off the walls rather than dissipating in all directions, which is effectively bringing you closer to the source of the sound, or making it louder.