Here's an overview of how the first ear training deck works. You will hear an audio and are prompted to "Describe what you hear." When you see the answer you are given a visual and will hear the audio again. Below is a sample of one of the visuals. The way the tetrachords are tilted show you whether the pitches ascend or descend. In this example you the upper diatonic tetrachord ascends from dhi to ni' and then the upper soft chromatic tetrachord descends from ni' to dhi. It's good to note that the distance from zo' to ni' is the same in both tetrachords.
If you'd like to watch the video for this class, you can find it on my You Tube page.
I also printed some tetrachord cards at Kinko's to test out with my students. They will be used in level 1 for ear training and in level 2 & 3 to prepare for reading fthore.