Is that because you were souring the milk? ;) Or was it the sound leaking in? I do have a degree in Music Technology Turuloid, as I stated earlier, which includes training in acoustics and design. That link is pretty good for a very basic and easy to build damping system, and it's the method i'd first turn to. If you check, there's also a table of absorption coefficients, which you can use to calculate problem frequencies in your room (using the handy Mode calculator on the site too!), and you can then target those specific frequencies with the design of your absorbers. Personally, I prefer to diffuse rather than absorb (especially in the upper freq's), but in very small rooms sometimes that's the only option.