You must have your Google Search language set to US English and be rooted.
You don't need Google Home Launcher for this works pretty well in stock launcher
Google Play Services 5.0
Unleash The Google
* Install the above three apk's
* Open Unleash The Google and grant root access to it
*Force stop Google Search once UTG has ran
*Then go into search settings
*Open config flags. Enable both e300 toggles(its enabled by default if not make sure to enable it)
*Add the country code(en-US) in "speaker_id_supported_locales".
*Save the config by tapping save config settings at the bottom.
* You are done
@ankitsuthar for Google Search 3,5
@TeamMex for Google Play Services 5.0
@ zhuowei's for Unleash The Google
@pico hackr for sharing it