Howling pipes

I have been in this house over 10 years and never had this issue before. This started a couple weeks ago when I first heard it I thought the neighbors dog was howling. It sounds exactly like that. A single, faint (distant) dog howl. But now I realize whenever you shut off any water source you get this short howl. It happens with any source - bathroom flush, kitchen sink, outside hose, etc. What is going on and can it easily be fixed? Nothing at all has changed in the house.

possibly sounds like a loose washer somewhere...I would start with isolating one fixture at a time so you would isolate your kitchen sink hot and cold ...then run the water somewhere else.. then shut off your dish washer feed....then run the water somewhere else....then shut off your icemaker....after each test leave each tested fixture off
until the noise goes away......it may be hard to isolate your shower valve unless you have integral stops that's just an idea