I have a new neighbor in the apartment below me who has been tinkering with his plumbing for several weeks. He's now increased the water pressure so much that when he turn it on it sounds like a fire hose it's so loud. Is there anything I can put around my water pipes so that the noise from him isn't so loud? Thanks.

So, he installed a booster pump in his apartment downstairs?

Because there is no other way for him to boost water pressure in his unit.