steam whistle

English: "The old train blew its steam whistle before departing. "
Persian: "قطار قدیمی قبل از حرکت سوت بخارش را کشید. "
English: "Factory workers recognized the shift change by the steam whistle. "
Persian: "کارگران کارخانه تغییر شیفت را با صدای سوت بخار تشخیص می دادند. "