I have a shower that makes a high pitch whistle when the hot water is running?

I have a shower that makes a high pitch whistle when the hot water is running? This indicates a vibration in the supply or cartridge. Shut the water off and open the valve. Pull the cartridge and check the inlet ports for any trash or crud. Now turn the hot water back on for a minute to flush out the supply and valve body. Reassemble and test. Better now? Tom