The air is moderated by the lips, curled tongue,[1] teeth or fingers (placed over the mouth or in various areas between pursed lips) to create turbulence, and the curled tongue acts as a resonant chamber to enhance the resulting sound by acting as a type of Helmholtz resonator.
Many expert musical palatal whistlers will substantially alter the position of the tongue to ensure a good quality tone.
Their whistling aided in conveying messages over far distances but was used also in close quarters as a unique form of communication with a variety of tones.
For example, whistling in theatre, particularly on-stage, is used by flymen (members of a fly crew) to cue the lowering or raising of a batten pipe or flat.
[11] This method of communication is usually done by having a sentry stand on two feet surveying for potential threats while the rest of the pack finds food.
[14] Many performers on the music hall and Vaudeville circuits were professional whistlers (also known as siffleurs), the most famous of whom were Ronnie Ronalde and Fred Lowery, in German speaking area Ilse Werner The term puccalo or puccolo was coined by Ron McCroby to refer to highly skilled jazz whistling.
[16] It also prominently features in the score of the movie Twisted Nerve, composed by Bernard Herrmann, which was later used in Quentin Tarantino's Kill Bill.
In the United States and Canada, whistling is used much like applause, to express approval or appreciation for the efforts of a team or a player, such as a starting pitcher in baseball who is taken out of the game after having pitched well.
In much of the rest of the world, especially Europe and South America, whistling is used to express displeasure with the action or disagreement with an official's decision, like booing.
[18][19][20][21] In the UK there has historically been a superstitious belief in the "Seven Whistlers" which are seven mysterious birds or spirits who call out to foretell death or a great calamity.
In the 19th century, large groups of coal miners were known to have refused to enter the mines for one day after hearing this spectral whistling.
In Estonia and Latvia, it is widely believed that whistling indoors may bring bad luck and therefore set the house on fire.
A popular explanation is that traditionally sailors, skilled in rigging and accustomed to the boatswain's pipe, were often used as stage technicians, working with the complicated rope systems associated with flying.
Transcendental whistling (chángxiào 長嘯) was an ancient Chinese Daoist technique of resounding breath yoga, and skillful whistlers supposedly could summon supernatural beings, wild animals, and weather phenomena.
In Thailand, it is believed that whistling is inauspicious at night, especially when indoors, because it is an invitation for a ghost or a snake to enter the house.