Google has added other nifty feature to Google Voice, adding voice calling to people through Google Voice. The feature is available even to those who don’t have a Google+ profile. It also works when you’re using Hangouts outside of Gmail.
The feature can be used in Google Voice by selecting Hangouts from the “Phone to call with” drop down menu. With that Google has added another clean feature to Hangouts, which it is trying to pit not only against instant messaging services like WhatsApp, but also video and voice caling services like Skype and Viber. We might see Voice getting phased out completely in the future, with Hangouts as your one stop shop for all your communication needs.