White sound device

A White sound device was an instrument in use aboard Starfleet vessels that was able to mask individual sounds from sensor devices. It was employed on the bridge of the USS Enterprise (NCC-1701) in the year 2267 during testimony in the court martial of Captain James T. Kirk. Doctor Leonard McCoy used one to mask the sound of the remaining crew members and court personnel's heartbeats allowing the sensors to detect Lt. Commander Ben Finney's who was previously thought dead but was found to be hiding in engineering.