With authorities "all but certain Malaysia Airlines Flight 370 went down in the south Indian Ocean in water that may be as deep as 23,000 feet," the U.S. Navy has a microphone that could help a lot in finding the missing aircraft, according to a story on the website of Wired magazine.
The microphone is called a tow fish.
The story reports: "The 70-pound tow fish, which is formally known in true Pentagon style as Towed Pinger Locator 25, is a hydrodynamic microphone designed specifically to listen for the acoustic signal of the data and cockpit voice recorders carried aboard all commercial and military aircraft. It can track the devices to depths of 20,000 feet.
“’Basically, this super-sensitive hydrophone gets towed behind a commercial vessel very slowly and listens for black box pings,’ says Commander Chris Budde, U.S. 7th Fleet operations officer."
The article adds: "The U.S. Navy deployed a pair of tow fish aboard the Seahorse Standard, a Royal Australian Navy Rescue Support vessel that will drag it through the search area west of Perth, Australia. The Standard joins a flotilla of a dozen ships scouring a vast swath of sea for any sign of the Boeing 777-200ER, which vanished March 8 enroute to Beijing from Kuala Lumpur."
The Seahorse Standard, equipped with the powerful tow fish microphone, will search for the missing Malaysian jetliner