Change the Nexus 4 voice dialer When I double tap the main button of my Bluetooth headset a voice dialer pops up. I'm not sure what app is this voice dialer (I couldn't find it on the apps list), all I know is that it's slow to load and works poorly. 

I'd like to replace this app with the standard voice search of the Google Search app. Is there a way to achieve this? 

Rooted options welcome.
I solve this on the Nexus 5 using Tasker with AutoVoice plugin.

Once you get both installed, add a profile that reacts to the "AutoVoice BT Pressed" event with the action for running the activity for Google:Voice Search (long clicking on the Google Search app and selecting VoiceSearchActivity from the activities presented.