One of my most used features was hands free dialing using my bluetooth and voice dialing. Just push the talk button on the blutooth and the phone started listening for my command. After the Android 4 upgrade I can not initiate calls from the bluetooth
I'm no expert with bluetooth matters, but it occurs to me that maybe you need to run through the pairing routine again.
If that isn't the problem, perhaps it's the app that you are using to do the voice dialing. What do you use? I used Choice Dialer Plus for almost two years, first with the original EVO and then with the 3D, and it worked beautifully. But it won't run under Android 4 and the developer says it never will. Perhaps other dialer apps are affected the same way. I haven't found any replacement app yet that works the way I would like. Plenty of them will respond to simply pushing the talk button, but they either ask for a key to be pressed to confirm the number they think they should dial, or they go ahead and dial whatever they think the number is, whether it's correct or not.
After I updated to ICS, my phone connected to the bluetooth speaker without me doing anything. I don't use any app for voice dialing. When I hold down the talk button on my bluetooth speaker, the phone asks who I want to call and I simply say the name and it dials fine. No problems here.
There was nothing special I had to do. Works just like it did before ICS.
That is how mine worked before the update. No app, just hit the talk button and the phone went to vice mode. After ICS, hit the talk button and nothing happens
There is some kind of Bluetooth bug in the official ICS patch for the EVO 3D. I don't know the specifics of it, so I'm not sure if this is what is affecting you, but if you are, the folks at XDA already have a fix if you are brave enough to root your phone. Otherwise, wait for an official patch. Since it's a known bug, presumably they will put out a fix for it.
Again, I'm not sure if this bug is related to your issue or not. I'm sure you won't have to spend much time on Google to clear that up.
Hope it is a bug. Not that i like bugs but a bug has a chance of being fixed. Loosing voice dialing could be a big liability for Sprint if users need to start using handsets instead of handsfree dialing while driving.