The whistle of a kettle is a simple reminder that your boiling water is ready to be removed from the stove. Most kettles come with a spout that whistles, but occasionally you may encounter a kettle that doesn't. You can turn your non-whistling kettle into one that whistles with a quick trip to the hardware shop and a couple of minutes of your time.
Fill your kettle with water, making sure the water doesn't go higher than the bottom of the spout.
Insert a rubber stopper in the end of the spout. The stopper must fit snugly, so you will need to push it in firmly. When choosing the proper stopper, the small end must be 6 mm (1/4 inch) smaller in diameter than the diameter of the spout and the large end of the stopper must be about 6 mm (1/4 inch) larger in diameter than the spout. Select a stopper with a small hole in the centre.
Turn the stove on to its highest setting for maximum heat. Once the water starts to boil, the small hole in the rubber stopper will create almost the same whistling noise as a standard whistling kettle.
If you don't plug the stopper tightly into the kettle, too much steam will escape around the sides of the stopper and your kettle won't whistle. If your kettle is whistling too loudly, use a drill with a drill bit that is one size larger than the hole in the stopper and enlarged the hole. The larger hole will allow more steam to pass through, reducing the steam pressure and quietening the whistle.
Wear an oven glove when removing the rubber stopper from the kettle. The stopper will be extremely hot once the water comes to a boil, and you could burn yourself.