<p>Facebook and WhatsApp logos are displayed on portable electronic devices on February 19, 2014 in San Francisco. Facebook Inc. announced that it will purchase smartphone-messaging app company WhatsApp Inc. for $19 billion in cash and stock. Justin Sullivan, Getty Images</p><p>WhatsApp, the popular messaging service for smartphones that's being acquired by Facebook, has announced plans to start offering a voice service.</p><p>CEO Jan Koum said the voice service will be rolled out for Android and iPhones this spring, with Blackberry and Microsoft and Nokia phones coming later.</p><p>"We are going to introduce voice in WhatsApp in the second quarter of this year," Koum said at the Mobile World Congress in Barcelona, Spain. "I think we have the best voice product out there. We use the least amount of bandwidth."</p><p><a href="http://www.cbsnews.com/news/whatsapp-adding-voice-calls-to-its-messaging-service/">Keep reading...</a></p><p>Read also:</p><p><a href="http://abcnews.go.com/Technology/wireStory/whatsapp-add-voice-messaging-service-22645238">WhatsApp to Add Voice to Messaging Service</a> (ABC News)</p><p><a href="http://www.usatoday.com/story/money/business/2014/02/24/whatsapp-messaging-service-apps-voice/5773559/">WhatsApp messaging service to add voice</a> (USA TODAY)</p><p><a href="http://www.theguardian.com/technology/2014/feb/24/telegram-messaging-app-whatsapp-down-facebook">Messaging app Telegram added 5m new users the day after WhatsApp outage</a> (The Guardian)</p><p>Explore: <a href="http://news.google.com/news/more?ncl=dbtM2y-TJSfn1qMi8yS7bFelg8-8M&authuser=0&ned=us">1,209 additional articles.</a></p>