Had to convert a room to a HCP accessible full bath... about the same time the house developed this pulsating thumping on the cold water side... all faucets/ toilets when they use water, I get a pulsation that is about equal to .01 galllon frequency (I had a walkie talkie in the house and watched the water meter needle and found the sound is synched.
I do not get this with hot water usage.

I have had the inside pressure regulator replaced. I have had the outside pressure regulator at the pump replaced. I have had the pump replaced. I'm $500 poorer and still not enjoying the vibrations in the pipes.