The four pings heard during the search for Malaysia Airlines Flight 370 are not thought to have come from the missing plane's black boxes, CNN is reporting. 

A 329 square-mile section of ocean floor were searched without a sign of the missing airline.

Officials say they are confident if the pings had been from the plane, they would have found it in the search area. 

Authorities say they now believe the pings were not from Flight 370's wreckage but from some other man-made source not related to the plane.