Ear Training 101 is a program that will train you to recognize relative pitch. This program will train anyone who wants to learn to play the piano in identifying the pitch they hear. The users will have to press the right key to repeat the sound played by the program. The program offers twenty-two levels of difficulty, from the simplest one (two notes with a max distance of Major 2nd) to the hardest (four notes with a max distance of an octave plus a Major 7th).
You can run the lesson in melody mode (that will play notes in a sequence) or chord mode (all notes played together). You can tell the program if you want it to show the right notes when you fail to recognize them, or not. When you are ready to take the test, you must click on the "Click to begin" button. The program will then play notes, and you will have to repeat the sequence, by clicking on the right keys. If your answer is correct, the program will perform a harder combination. If you fail, it will start from the scratch. After you have answered all the levels successfully, the lesson is over.
In brief, Ear Training 101 is a good way to train your ear to recognize notes.