I have two commodes that have an obnoxious whistle when the tank fills after flushing. How can I get rid of the whistle? Thanks.

I have two commodes that have an obnoxious whistle when the tank fills after flushing. How can I get rid of the whistle? thanks. Hey Mary,
Tell us what type of ballcocks that you have. (see images) The noise you hear is caused by something that's vibrating in the ballcock but we have to know what you have before we can help. Regards, Tom