Based on the answers provided, the following corrections need to be made to the 3D object:

1. Modify the object to resemble a whistle. This could involve adding a hole for blowing air through and adjusting the overall shape to be more tubular.
2. Add a rectangular block extruding outwards from the curved surface of the cylinder. This is currently missing from the design.
3. Ensure that the rectangular block is located at the top center of the cylinder. 
4. The rectangular block should be narrow, very short, and longer than the diameter of the cylinder.