Crews race to trace underwater sounds

Operators monitor TAC stations onboard a RNZAF P3 Orion during search operations for wreckage and debris of missing Malaysia Airlines Flight MH370 in Southern Indian Ocean on April0 4, 2014, near Australia.  Up to fourteen planes and nine ships resumed in the search for missing Malaysia Airlines flight MH370 in the Indian Ocean off the coast of Western Australia today. The airliner disappeared on March 8 with 239 passengers and crew on board and is suspected to have crashed into the southern Indian Ocean.

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    Crews race to trace underwater sounds

Crews are investigating the two pulse signals detected by a Chinese ship. CNN's Matthew Chance reports.