This is the same as the original funky 3 tone whistle, only there is no outer air chamber. This whistle blows straight on instead of curving the air flow around inside.
Print with 3 solid layers for solid surfaces, 1 extra shell on alternating solid surfaces, and be sure your flow rate and line spacing is set properly.
If you do not have your solid layer fill and bridge settings correct, the whistle will not work. You can add a few drops of acetone to the solid surfaces and that will seal them up if they aren't working properly.