It’s proper term is Bosun’s call, not Bosun’s whistle.
I shared an apartment with a BM3 buddy he called it a whistle LOL. The term piping also comes to mind the actual call and announcement to follow. All I know for certain is when I got onboard ship in early 77 they were not to be heard anywhere. We came back off a 77-78 Med Sea cruise and were hearing them while in the yards.