jorge emailed this to me, and i hope he doesn't mind that i share this, but it's from a book by armen donelain(sp?) and practicing these really bolstered my aural abilities:
1 - Singing is the key for good ear training
2 - Always sing by numbers
3 - Sight Singing is also essential (for these there are plenty of other good cheap books available)
Exercises (sing everything in the 12 tones, I usually make a random note order; you can sing with the chord in background, just the tonic as a pedal note or internalize the tonic before and sing with no background)
1 - Scrambled Triads - (135, 315, 513, 153, 351, 531) - These are the six possible combinations for the triads notes, sing for all the triads you know;
2 - Scrambled Seventh Chords (1357, 1375, 3157, 3175, 1537, 1573, 5137, 5173, 1735, 1753, 7135, 7153, 3517, 3571, 5317, 7153, 3517, 3571, 5371, 5317, 3715, 3751, 7315, 7351, 5713, 5731, 7513, 7531) These are all the possibilities, sing for all the seventh chords you know
3 - Scrambled scale patterns - basically make a random organization of a scale like 3 5 6 2 4 7 1 and sing for all the scales (for scales like the whole tone or the diminished you must adjust the number of notes). You can make any pattern you want, the idea is to be able to hear all chord tones related to each other.
4 - 13 Chords. Singing chords by thirds: Major 7h (1 3 5 7 9 #11 13), Dominant 7h (1 3 5 b7 9 #11 13), Minor 7h (1 b3 5 b7 9 11 13), Locrian ( 1 b3 b5 b7 9 11 b13) - you can sing the minor with a major 7h also and the dominant as an altered starting on the # 11 - singing the Db dominant pattern over a G bass. You can sing them in a row ascending and descending and also as triads (135, 357, 579,...) and seventh chords (1357, 3579, 57911, etc...) ascending and descending. The idea is to learn the sound of extensions and to hear them as groups of upper extension triads.