Do a noise audit. Listen to the workplace for a few hours, recording every sound. Categorize those sounds into normal operations and abnormal conditions.
For the normal operations, look at the loudest sounds and check if the process can be redesigned to limit the sound. A smaller number of larger bolts, for example, might be less noise intensive to install with an air ratchet than a larger number of smaller bolts.
For the abnormal conditions, identify the underlying problems, and work to eliminate them. If you have some way of prioritizing the problems, make sure that these issues get into the decision-making mix.