Whistling kettle

A whistling kettle, or tea kettle is a kettle fitted with a device that emits an audible whistle when the water in the kettle starts to boil. The action of steam passing through the device causes vibration, in turn creating the sound, known in physics as a hole tone.

The exact mechanism by which this occurs was not fully understood until a paper, The aeroacoustics of a steam kettle, was published by R. H. Henrywood, a fourth-year engineering undergraduate at the University of Cambridge, and A. Agarwal, his supervisor, in the journal Physics of Fluids in 2013.