The didgeridoo originally comes from the Northern Territory in Australia. It is a wind instrument traditionally made from the trunk of a termite hollowed eucalyptus tree. They average about 4 feet in length, and are played by vibrating your lips into the top end of the instrument which creates a deep humming drone.
The didgeridoo is a rhythm instrument, so you play "beats" instead of melodic songs. Play at your own speed as well: quiet or loud, fast or slow... you'll develop your own style. There are no rules or complex memorization. This makes learning the instrument is very intuitive, so you don't need any musical training or years of lessons to enjoy playing the didgeridoo straight away. And there's no lung power needed as with other wind instruments. The didgeridoo is played with gently vibrating lips, voice, and tongue movement, not lung power. You won't believe how quickly you can learn this and how much fun it can be.
The didgeridoo can be played softly and quietly simply by relaxing your breath. In fact the more gentle you play, the more expressive you came be. So there is nothing to worry about with the neighbors.