The role of the larynx.
We carried out a flexible endoscopic study to observe the movements of the larynx while whistling tenuto (sustain), staccato, glissando, and vibrato techniques similar to those of violinists and flutists. The sound production of two test subjects was assessed: P1, an experienced whistler, and P2 a person not experienced in whistling, though with a good sense of musicality.
During sustained tones the vocal folds constricted close to the midline of the glottis, resulting in a narrow gap (for both P1 and P2). The experienced whistler, however, in addition constricted his vocal folds up to the rear third of his false vocal folds (!).
During staccato both test subjects fully constricted their vocal folds. P1 showed during accented staccato a marked constriction of the false vocal folds and a light peripheral constriction of the supraglottal structures (aryepiglottic folds).
During "violin-type vibrato"-- or, the common method of whistled vibrato wherein the pitch is significantly altered-- a strong simultaneous movement of the tongue base occurred with a slight movement of the connective larynx structures (for both P1 and P2).
During "flute-type vibrato," in which the volume (loudness) is significantly varied (for P1 only), there occurred simultaneous constriction-retraction motions of the vocal folds and false vocal folds.
During glissando, the larynx elevated and the aditus laryngis (opening of the larynx) gradually constricted. Consequently, the larynx followed the movement of the elevated tongue base and the protruded tongue.
Conclusions: The larynx has an important role in governing the airstream during the musical formation of sound during whistling.
We carried out an experimental study to identify possible correlations between whistling pitch, intensity (volume, loudness), airflow and internal oral pressure. The equipment we used was the Voice Function Analyzer Aerophon II (
The task was to whistle a diatonic scale from d2 to d4 in staccato as well as glissando manners, at a comfortable volume. It is worth mentioning that the regulation of the intensity in the mask was not as easy as usual. The results showed that SPL values could not be reproducibly assessed, probably due to the acoustic dampening of the system, which was designed for measuring the human voice, not the human whistle.
Rounded lip mode:
Increased pitch was accompanied by increased oral pressure. The correlation between these components seemed to be nearly linear in the lower pitch range and slightly exponential in the upper pitch area.
The intra-oral pressure was measured in centimeters H2O. The pressure at d2 was 0.7, at d3 2.0, and at d4 5.5 cm H2O. The airflow increased during the first octave of the scale; after that it stagnated, or in other cases decreased slightly. The range of the rate of flow was measured between 0.1 and 0.5 l/sec.
Palatal mode (using by Tamas Hacki):
The pressure measuring tube could not be inserted into the space enclosed by the tongue, therefore only airflow was measured. The changing of the airflow during pitch rising showed the pattern as follow: during whistling from f2 to f4 airflow slightly rose until about the mid of the second octave, afterward it stagnated. The flow values were measured between 0.1 to 0.15 l/sec.
Pitch rising requires an increase of intra-oral pressure. Flow proportionally depends on two factors: 1) intra-oral pressure and 2) lip aperture. The higher the pitch, the narrower the lip aperture. Thus intra-oral pressure and lip aperture influence the airflow counter-proportionally as pitch increases.
Whistling is a highly complex task which includes most of the organs that play a role during singing. The human whistle as a "musical instrument" requires a precise coordination among physiological and acoustical components, the mastery of different techniques and styles, and of course a high degree of musicality.
Further information about whistling technique and musical aspects of whistling art you find on the home page of the International Artwhistling Philharmonic Society IAPS (http://www.synthonia.com/IAPS/).