Me, too, Peter! Who care ?

A lot of singers do that ... the problem is that if you don't sing it right out, you cannot hear the counterpoint between the correct interval and the incorrect interval. After a while of doing this, you will be able to sing the interval correctly. If you read music, visualize in your mind the scoresheet and the notes at every step of the interval. You may find yourself using your eyebrows to "punch" (for lack of a better word right now) the notes. This may help. I don't know if visualization came naturally, or if I learned it along the way, but that's how I do it and it works. And, Peter, Rick's right ... "nail the sucker."

Jenny