I'm having some problems to get my voices to work in Mac OS X.
I downloaded the package, OS X autoextracted the .uqm file and I put the comm-folder to packages-folder. However, nothing happens. What is the problem?
That's your problem right there. UQM expects the .uqm files to remain compressed (i.e. just the way you downloaded them) if you put them in the packages folder. This is why they don't have a normal .zip extension.
If you put the comm folder in the content folder (the one that contains the packages folder), the speech should also work.