No sound

I bought this app for my 4 year old grandson, who is interested in maps and the states. He is not yet reading, so I was relying on the app voicing the names of the states or capitals, but I cant get the sound to work. I have the sound on -- both on the menu of the app and on my computer and am using an iMac OSX 10.7.5, so shouldnt be having problems. I contacted the developer and hope to hear back soon.

If the voice works eventually, it sure looks like an engaging and educational app, well worth the cost.

UPDATE; Its been three and a half months, and I still havent heard back from the developer. has anyone been able to get the app to speak the names of the states as they come up, or isnt this a part of the program? (I think it should be, since youngsters are capable of learning this before they are able to read.)

Penny TX about 50 States and Capitals