Welcome, Isadora.
Have you tried looking online under dictionaries that provide audio files?
If you're interested, here's an English-Thai online dictionary with audio:
http://www.learn-thai.com/learn-thai/OL_DIC/vocab.asp (sign up is required).
I'd like to help more, but I don't know how. That is, I could give you Japanese, which is my third language, but how would you know how to pronounce the words? That's a problem.
Ooh, here's an idea: what about Sign Language?
Here's a very cool site:
http://www.masterstech-home.com/ASLDict.html