https://www.prnewswire.com/news-releases/nasa-ramps-up-space-launch-system-sound-suppression-testing-242452481.html
NASA Ramps Up Space Launch System Sound Suppression Testing
/PRNewswire-USNewswire/ -- The first round of acoustic tests on a scale model of NASA's Space Launch System (SLS) is underway. The tests will allow engineers...
space launch systemsound suppressionnasarampstesting
https://pure.psu.edu/en/publications/calculation-of-sound-propagation-in-nonuniform-flows-suppression-/
Calculation of sound propagation in nonuniform flows: Suppression of instability waves - Penn State