In Maine, whistles were just that: whistles. A device through which to make a loud sound, with no exterior connotations attached. Certainly no one carried one around, unless you were on a hunting trip and even then it was an optional accessory. I think when I was in high school, a mention of a whistle would probably call to mind that Frosty the Snowman movie- the old-school animated one that plays every year on ABC family around Christmastime. There’s a scene with a huffy, tiny policeman directing traffic, and he’s getting redder and hoppier and jumping mad, and he keeps blasting on this whistle, over and over.
In Boston, and probably any urban area, a whistle is a rape whistle. It has no other purpose. Even if the maker was making an ordinary whistle, it becomes a rape whistle in the city: a device to call for help should someone make an unwanted advance or attack. My two roommates and I (all female) were each given a rape whistle by our broker when we moved into our new apartment. Mine is metallic green, and made out of a single block of metal. It’s a cylinder shape, with a hole on top for air to pass through, and a hole on the end to blow into. I keep mine on my key ring, in between the mailbox key and my Swiss Army knife (because I’m both a former Mainer as well as a former girl scout and I think “Be Prepared” is a universally good idea).
In the last year that I’ve carried it on my person, I haven’t had the need to put the rape whistle to use other than to test the sound on first receiving it- knock on hypothetical wood. It is just another keychain, one that makes noise if I blow air into it. A toy.