An instrument that produces, by having air (or steam) blown through it, a shrill sound. Air-whistles were made in ornamental form from the 16th century, to be hung as a pendant or from a girdle or chatelaine (sometimes used for calling domestics), and are shown in Renaissance paintings and Dürer engravings.
Some were made of gold or silver, with chasing or enamelled decoration, and some carved of boxwood. One made for Henry VIII, set in a finger ring, was decorated with diamonds and ruby. Examples were hung with silver bell to ward off the 'evil eye', and some were in the form of a case to hold toothpicks and ear-picks.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson