Non plumber condo owner in CA
After 12 years no noise, our pipes are singing. It can happen on any
fixture. Not real bad, just enough to notice. Same with our next door
neighbors who have a separate water service.
Plumber friends suggest prv, so I call the City Water Dept., they come out, and say you don't have a prv, because your main supply is only 55psi at the hose bib. Everyone is stumped as to what the cause is.