If faucets screech when you turn them on and pipes hum when water's running, chances are you have a bad main inlet valve or a bad pressure regulator valve. Water enters a home at only one point, and if all faucets groan and howl the same all through the house, the main inlet valve is bad where water enters your home. Over time, rubber gaskets can become brittle. Running water rushes in, passing over the gasket and acts like the reed in a clarinet with pipes carrying the sound to every faucet and fixture, making it hard to pin down the source. In this case, check the main inlet valve, but if it screeches at only one location, then check the gasket of that particular faucet. Repairs can be done with basic tools for under $10.

If that doesn't do the trick, consider investing in a pair or earplugs?