Wolf-whistling or finger whistling is a type of whistling in which fingers are inserted in the mouth to produce a louder and more penetrating tone.A wolf-whistle is a two-toned sound (like 'whip-woo') commonly made using the above technique to show high interest or approval of something or someone (originally a young girl or woman thought to be physically or sexually attractive).  fingerless wolf whistle (help·info)The wolf-whistle originates from the navy General Call made with a boatswain's pipe. The general call is made on a ship to get the attention of all hands for an announcement. Sailors in harbour would whistle the general call when seeing a pretty woman to draw fellow sailors' attention to her. It was eventually picked up by passers-by, not knowing the real meaning of the whistle, and passed on. Over time, the precise tones of the general call were flattened somewhat into the wolf whistle common today.[citation needed] Today, cat-calling or wolf-whistling can be considered a form of sexual harassment.