Technical arrangements that can help you:

Damp noise – for instance, shut off equipment that is not in use, avoid banging metal on metal.
Damp noisy machines – such as by using cabs on contract machinery, enclosing compressors and sound locks.
Use less noisy methods where possible. – such as blasting/cutting instead of cutting with a drilling hammer. Also, buy materials of set dimensions so as to avoid having to cut them.
Keep noisy work low – e.g. recesses for holes in concrete flooring instead of cutting them in afterwards.
Use good quality tools and machinery – they will generate as little noise as possible.