Practice them until you master them. Press the button for the pronunciation you hear. They distinguish between a /tɕ/ without aspiration and an /tɕʰ/ aspirated. The button to identify what you hear has the IPA characters, and the label below it the corresponding Pinyin in red. Listen to a puff in the case of the aspirated. In the image you can see the difference, and the blue line shows you the frequency variation for the tone.