"Where are they?" Fermi

Earth has emitted radio signals for 100 years now. That means any civilization within 50 light years may have noticed us. Unfortunately there are very few stars within 10-20 light years, but an enormous number out 100 light years. So it is entirely possible we have been discovered. But it is likely we will not hear from them for a few more decades. https://news.yahoo.com/alien-civilizations-may-able-send-150000048.html 

Alien Civilizations May Be Able to Send Us Messages by the End of the Decade Jackie Appel