Usually when an airplane breaks the sound barrier, it is heard a thunderous noise. Researchers from NASA also wants to create a plane that makes it silently. It is expected that this will make the plane again real supersonic passenger flights on which at one time abandoned because of high noise levels.
Currently, researchers are developing ways to reduce the overall noise level. This includes testing of various forms of the fuselage, as well as carrying out sound experiments to determine when noise will override the sound barrier begins to interfere with passengers.
In NASA hope to create a working prototype by 2025. It will pave the way to the return of passenger supersonic aircraft, breaking an important legal barrier: that such planes can not fly over populated areas because of too high noise levels. Sound tests will completely change the shape of the aircraft, to eradicate this problem.