There has been a lot of rumors about WhatsApp starting call services, but it was all in wait as no date was given when the services would start. Finally WhatsApp voice feature has started but currently it is only available for some users and not all. News is that a user who got the voice feature called one of his friends whose voice feature got activated, but it is not certain that this is the only way to get the voice service activated. Other suggestions are that to get the latest version of WhatsApp users need to download the application from the official site and not from Google Play. I am yet to download the application so will update the thread.