The chamber has walls made of solid concrete half a metre thick. You might be surprised that a satellite must be tested on the noise of a launch. The loud noise of the launcher can shake the satellite.
Low tones are the main problem.
Obviously the noise vibrations a satellite is exposed to on top of the launcher are much more severe. The noise level can rise to more than 150 decibels. This is simulated in this chamber. Although the massive doors are kept tightly closed, you can always hear a low rumbling outside.