Digital assistants are evolving from being mute servants to proactive partners. And Google wants to ensure the way you call out to them for assistance also changes from being authoritative in tone to one that is more natural.
Google Assistant, which is at the heart of compatible devices, including Google Home, for all your queries ranging from trivial to serious, can be summoned by saying, “OK Google”. However, this is set to change soon. Google recently added support for “Hey Google” functionality to Google Home. The voice command is similar to “Hey Siri”, and makes the interaction between human and machine slightly more realistic.
Now, as per latest reports, the functionality is set to soon be rolled out to compatible smartphones as well. As per Android Police, the support for “Hey Google” has not been released universally to all devices. It is currently working on some devices, and you will get a prompt for the update. You can also head to the Google Play Store for an update to the Google app. The Assistant will require you to re-train it for both the “Hey Google” and “OK Google” variations. Once you do that, you can then use either of the commands to ask about the weather, set reminders, or send text messages. 
Digital Assistants are fast becoming kind of a shortcut for users to reach out, find out, or simply put it out onto the digital medium. One of the important, often overlooked, factors driving the usage is that it does not require very high levels of device literacy, one could simply talk to their phone and get information.
Recently, Apple improvised its Siri by making it sound less robotic. The company used machine learning to train the speech recognition system to create natural-sounding responses. With such a training, it is expected that asking Siri questions about traffic or making it read a special message would no longer mean robotic, monotonous responses.