This is a simple horn (think: foghorn) that utilizes a balloon and a section of 1/2" schedule 40 PVC. The noise is pretty loud, about the same as a automobile horn, and the frequency is adjustable by using different lengths of PVC, or by using PVC with holes in it like a flute. The sound is created by blowing into the tube through the smallest hole.
After printing, place a section of balloon over the largest hole and hold it in place with a rubber band. After this, insert a section of 1/2" PVC through the middle so that it presses lightly against the balloon. I find that a 16 inch section of PVC creates a nice fog-horn type sound. Blowing into the small hole should create noise.
I had to sand the inside hole slightly to get the PVC to have a perfect fit.
Adjusting the tightness of the balloon and the PVC's pressure against the balloon will adjust both the volume and quality of your sound. Experiment!
I print a bunch of these for my students, and then I have many pre-cut sections of pvc in the classroom. Students can experiment with the different lengths and document the frequencies created. It makes for a very noisy and fun way to study sound waves! Soaking the printed plastic in disinfectant between classes eliminates any sharing of germs.
You should have success regardless of your print settings. You will have to sand the PVC hole slightly.