Thanks for your post!
I apologize for the delay in responding. I'm not sure if you're aware, but our office is located in Christchurch, New Zealand and on Saturday September 4, we experienced an earthquake of magnitude 7.1. Our office, along with all of the central city, was shut all last week and we are just returning to work today.
In order to listen to the words in your My Vocab list, you need to click on the tab on the left side of the page that says "My Vocab." Once you've done this, a list with all of the vocab words you've added should appear. Next to most of them, there will be a blue audio box. Just click the 'play' (triangular) button to listen to the word. Unfortunately, at this point, not all of these words have audio attached to them. Our Product Development team is working on making this more extensive.
I hope this helps. Let me know if you have further questions.
All the best for your Chinese learning! :D