The differences might be there, but if only 30% of your guesses were correct, then from that it does not look like you can actually hear them. Choosing randomly you would guess 50% right on average. With 10 trials, a score of 8/10 means there is 5.5% chance that it was only by luck, and 9/10 reduces that to 1.1%. A commonly accepted threshold for "passing" the test is less than 5% chance of random guessing, and that is with a single run of a pre-determined number of trials.
2/28/15 at 4:41am