A lot of noise can be eliminated by good design, it is always too high, I don't think that there is an acceptably high level of noise, it all causes long term damage to your hearing.
Reducing structural transmission of noise/vibration helps, such as with Diesel Electric ships where the generator sets are mounted resiliently. Acoustic enclosures for high noise machinery such as air compressors helps. Proper maintenance of the rubber seals on doors around the machinery spaces stops noise leaking into the Control Room, workshop and accommodation. Use of Soft sound absorbent material would help, I am not suggesting scatter cushions and curtains everywhere, but in a house they make a huge difference, as anyone who has been round an empty house and come back when it is furnished can tell you. Years ago a system was developed that had microphones all round noisy spaces that picked up the noise, shifted it out of phase and re broadcast it, so that the Broadcast sound waves cancelled out the natural ones, worked very well on trials but was never adopted, probably too expensive and if it went wrong it could have doubled the noise level!
It is always better to ask a stupid question than to do a stupid thing.