Jason's approach: tie each interval to a song you already know. A major second is the first two notes of Happy Birthday. A perfect fourth is Here Comes the Bride. Build a mental library of anchor songs, then drill them back in context until the sound becomes automatic.
From Jason's actual lessons
Q
Why can't I hear chord quality differences?
Most students are listening to the whole chord when they should be listening to the third. The third is the quality-defining note. Isolate it — play just the root and third — until your ear locks onto that minor versus major distinction before adding the fifth back.
From Jason's actual lessons
These examples are illustrative. Ask Aria your own question and she'll search the lessons for the closest match.