Honestly, I took sound design classes with 20 other peoples and didn't even gain as much knowledge as I did with this program. And it costed my just a fraction of the costs.
The Answer is Syntorial
The cool thing about Syntorial is, that it's build behind real science of learning. I go deeper into detail in the video below.
In a nutshell what it does is;
You hear a sound then you reprogram it then you get feedback if it's right or wrong.