Hello Flavio,
you will have to use two different (but equal) images. Image A shows text, plays audio, hides itself and shows Image B. Image B hides the text, stops audio, hides itself and shows Image A.
As for the touchdown, that is the event that fires (once) when you press mouse button or touch an area, touch up is fired (once) when you raise your finger from mouse or screen.
Anyway, If you upgrade to PubCoder 3, you will find a new Tap event too.