the transmission level. >> meantime, they are guarding against noise interference, limiting the number of ships and aircraft near the ocean shield. 375 miles away, search crews haven't given up hope on the other pinging sounds reported by the chinese. two search areas, but so far neither has reacquired the sound they need. well, australian officials say they will keep searching for that pinging sound until there is absolutely no doubt the pinger batteries have expired. that means roughly another ten to 12 days or so. at the same time, locating debris is still critical. search crews have deployed data buoys to monitor water flow in hopes of locating that debris. of course, that will help them trace back to that point possibly where the plane went into the water. >> all right, rene, stand by. we're going to get back to you. let's go to the base of operations right now, the base of the operations for the search, our senior international