Vi
http://img.tapatalk.com/d/13/05/22/eza6e3at.jpgThe sound you hear may be the app waiting for you to speak-it will "ding" when ready. You will have to enable bluetooth in the Google Now settings to use it. I've not used the app with bluetooth personally but even so, I'd suggest you try a few commands just through the phone app to get the feel of it before moving on to bluetooth. I don't know but it's possible that the hot word ("Google", by default) detection may work via bluetooth. Please post your results. As to the default app the headset connects with, I really don't know how to answer but it may do so anyway since Moto is dead. Of course, you can always just uninstall the Play Music updates & continue as in the past. What you may try is to disable Voice Commands and see if it defaults to Google Now then - if not, there's an app in Google Play Store called "Bluetooth Launch" that enables you to select the app of choice for use.
EDIT: Play Music just updated again tonight but alas, the problem persist. Makes me wonder if this isn't part of the trend to remove all the "branded" apps possible replacing them with their own?
Sent from my Droid RAZR MAXX using Tapatalk2