When loudness is described there’s often lists with examples of things with their typical loudness specified in dB, so you can compare against things you may have heard.
See the image chart here
https://decibelpro.app/blog/decibel-chart-of-common-sound-sources/
Destructive interference is a thing. The energy of the vibrations doesn’t go away, however you CAN shift that energy into different frequencies and destructive interference done correctly will effectively shift it into so high frequencies that the vibrations are better compared with heat than with sound (what is heat convection anyway if not extremely high frequency sound? :)