NASA and Lockheed Martin are nearly finished with their supersonic test plane...

The space agency believes that the engine will allow the aircraft to fly without any sonic booms,  to prove the feasibility of supersonic flights over cities, a requirement for getting commercial airlines supersonic flights over the USA, probably other countries as well, to drastically reduce travel time for those who can afford it

As part of the upcoming test, the plane will fly over several populated areas and specialists from the agency will gather information on how people react to sound.

People are expected to hear a soft popping sound, comparable in volume to the sound of a car door closing. The space agency will pass on the data it collects to international and US regulators in the hope of gaining approval for supersonic commercial flights over land.

https://gagadget.com/en/247713-nasas-x-59-supersonic-passenger-aircraft-will-make-its-maiden-flight-before-the-end-of-2023/

https://gagadget.com/en/276619-nasa-and-lockheed-martin-show-the-x-59-quesst-supersonic-aircraft-preparing-for-its-first-test-flight/

https://www.electronicsweekly.com/blogs/gadget-master/gadget-in-extremis/gadget-in-extremis-nasas-quiet-x-59-supersonic-aircraft-2023-07/