First I identified the major noise generators: coffee grinder, air conditioning, television, alarm clock. Then I eyeballed a radius for each, based my own perceptions while living here. Finally, I color-coded their respective regions.
The result is a cool-looking map that can support quite a few lies. I wanted this map to be as simple as possible so I sacrificed things like exact noise level, exact boundaries, exact measurements, and pretty much anything else that required me to leave bed.
One thing that I learned is that overlapping colors become very confusing. Originally I wanted the coffee grinder red to cover the entire apartment because the coffee grinder can be heard in all rooms. The problem was that you couldn't then tell where it started and ended, even with the red dot denoted the source of the noise. It just tinted all of the other colors red without any indication it was doing so.
Another thing became obvious in that you really need to decide ahead of time what you want to focus on. Do you treat each noise as a distinct sound? Or do you treat all noise equal and just focus on area? Or do you do both, but incorporate measurements of the noise levels to differentiate them? Or do you...
This was never meant to be a highly accurate map, but even making this inexact map made me think about exacting requirements for other mapping endeavors.