I choose not to install the Google Voice app. It sucks too much battery and the messages are not pushed. So I choose the email notification, so I have a choice if I want to download the attachment. This method worked well for me with my Curve. The problem is the attachment won't play on my Tour. I had the same problem during my short stint with a Storm2.
I get as far as the BB player "buffering" - according to the indicator arrows it's not. It must be a setting or a code. I posted a Q on Google and ... well you can imagine how far that went.