Two things. First - from what I understand, he is made louder these days. He's very loud if you are in a quiet spot, like waiting for a show to start

(DS was having too much fun with him ALL the time!) but not too loud in the noise of the park. We would just hold him up to our ears as we walked and we heard him fine.
Second, if you want to have a bit of fun, check out the
Pal Mickey & Friends Adventures & fashions thread. I'll be posting my Mick's time at WDW soon - just as soon as I can post more phots to Photobucket (I'm having an issue with them right now, but that's another story...)