Toilet Plumbing Issue

jgb

DIY team:

When we flush one of our toilets it begins filling as usual. But within a few seconds a loud noise comes from the shut-off valve - like someone turned up the volume to max on the "running water" sound we usually only slightly hear when the water is going through the shut-off valve to the toilet tank.
Any ideas on what can cause this and what things I could do to troubleshoot this so it is quiet again?

Thank you, jgb, aka "John"