One of the best ear training methods I’ve encountered is functional ear training. With functional ear training, you focus on learning the specific sound of a note in the context of tonality instead of learning to recognize the sound of individual intervals. Instead of identifying intervals, the goal of functional ear training is to figure out how the note in question relates to the key center. That way you need not only the “note in question” but also a reference point – be it a drone, a backing track, or a background chord.