1 Samuel 3:9 So Eli told Samuel, “Go and lie down, and if he calls you, say, ‘Speak, LORD, for your servant is listening.’” (NIV)
I don’t know how we knew; we just did. It sounded like any other horn, but somehow we recognized it.
My cousin and I lived when boys were allowed to roam. And having grandparents who owned a farm allowed us many miles of fields and woods to do it in.