May I know if there is a way to send (or upload to server) voice from mic in realtime without record?. like whatsapp,viber voice call. i want to make calling app like that. can you tell me some method for do that. i new to this 
Perhaps try a community search, see what others have done...
https://community.appinventor.mit.edu/search?expanded=true&q=voice%20call