One critical bit of information that the Chinese got out of their inspection of the EP-3 electronic surveillance plane (and its supersecret manuals) was the knowledge that the US plane could identify individual Chinese officers by the sound of their voices. The EP-3E that was damaged and forced to land had just received the Sensor System Improvement Program and the Joint Signals Intelligence Avionics Family Block Modernization refit. This was the latest technology and provided the analysts with a static-free ear into the Chinese communications network. China has studied the aircraft's system and should be able to produce masking and filtering devices that insure that future US eavesdropping gets a distinctly less clear copy of the communications.--Stephen V Cole