Yeap! Finally Windows Phone users getting the voice call feature on WhatsApp after it has rolled out for months to Android & iOS users.

• WhatsApp Calling: Call your friends and family using WhatsApp for free, even if they’re in another country. WhatsApp calls use your phone’s Internet connection rather than your cellular plan’s voice minutes. Data charges may apply. Available on Windows Phone 8+. 

• You can now send audio files (available on Windows Phone 8.1+)

 You can download the latest version 2.12.60 from Windows Phone Store

Source: Windows Central