NASA researchers recently conducted a series of flights to record the sound of jet engines with the goal of using that data to help predict the way future engines designed for use by supersonic-capable aircraft might sound at takeoff.

The Learjet Acoustic Flight Test took place at Niagara Falls International Airport in New York, where the twin engines of a Learjet 25 owned by Calspan Corporation of Buffalo, New York, provided the sound as the aircraft was flown in various conditions.