Human whistling is the production of sound by means of carefully controlling a stream of air flowing through a small hole. Whistling can be achieved by creating a small opening with one's lips and then blowing or sucking air through the hole. The air is moderated by the lips, tongue, teeth or fingers (placed over the mouth) to create turbulence, and the mouth acts as a resonant chamber to enhance the resulting sound by acting as a type of Helmholtz resonator, producing a pure tone like a sine wave. Whistling can also be produced by blowing air through enclosed, cupped hands or through an external instrument, such as a whistle or even a blade of grass or leaf.

Whistling can be musical: many performers on the music hall and Vaudeville circuits were professional whistlers, the most famous of which were Ronnie Ronalde and Fred Lowery. Both had several notable songs featuring whistling.

Pucker whistling is the most common form of whistling used in most Western music. Typically, the tongue tip is lowered, often placed behind the lower teeth, and pitch altered by varying the position of the tongue. In particular, the point at which the tongue body approximates the palate varies from near the uvula (for low notes) to near the alveolar ridge (for high notes). Although varying the degree of pucker will change the pitch of a pucker whistle, expert pucker whistlers will generally only make small variations to the degree of pucker, due to its tendency to affect purity of tone. Pucker whistling can be done by either only blowing out or blowing in and out alternately . In the ' only blow out' method, a consistent tone is achieved but a negligible pause has to be taken to breathe in. In the alternating method there is no problem of breathlessness or interruption as breath is taken when one whistles breathing in . But a disadvantage of this method is that many a times, the consistency of tone is not maintained and it fluctuates.