what's happen?

hi, just want ask if someone can help me. For the second assignment in this blog, i can't do at all. i can't listen any sound. i've been tried many time. eventhough i try at home and library, this also same. i can't heard any sound from David crystal. i keep tried to click the title and "audio" and it's nothing. What should i do? anyone can help me in this, please....