A vocal register in the human voice is a particular series of tones, produced in the same vibratory pattern of the vocal folds, and possessing the same quality. Registers originate in laryngeal function. They occur because the vocal folds are capable of producing several different vibratory patterns. Each of these vibratory patterns appears within a particular range of pitches and produces certain characteristic sounds. The term register can be somewhat confusing at it encompasses several aspects of the human voice. The term register can be used to refer to any of the following:
In linguistics, a register language is a language which combines tone and vowel phonation into a single phonological system. Within speech pathology, the term vocal register has three constituent elements: a certain vibratory pattern of the vocal folds, a certain series of pitches, and a certain type of sound. This view is also adopted by many vocal pedagogists.
One prevailing practice within vocal pedagogy is to divide both men and women's voices into three registers. Men's voices are designated "chest," "head," and "falsetto" and woman's voices are "chest," "middle," and "head." This way of classifying registers, however, is not universally accepted. Many vocal pedagogists partially blame this confusion on the incorrect use of the terms "chest register" and "head register". These professionals argue that since all registers originate in laryngeal function, it is meaningless to speak of registers being produced in the chest or head. The vibratory sensations which are felt in these areas are resonance phenomena and should be described in terms related to resonance, not to registers. These vocal pedagogists prefer the terms "chest voice" and "head voice" over the term register. Many of the problems which people identify as register problems are really problems of resonance adjustment. This helps to explain the multiplicity of registers which some vocal pedagogists advocate. For the purposes of this article, resonance problems are relegated to their own area since their usage here is controversial and without an overall supporting consensus. For more information on resonance see Vocal resonation.
Vocal registers arise from different vibratory patterns produced by the vocal cords. Research by speech pathologists and vocal pedagogists has revealed that the vocal cords are capable of producing at least four distinct vibratory forms, although all persons cannot produce all of them. The first of these vibratory forms is known as natural or normal voice; another name for it is modal voice, a term currently widely used in both speech pathology and vocal pedagogy publications. In this usage, modal refers to the natural disposition or manner of action of the vocal cords. The other three vibratory forms are known as vocal fry, falsetto, and whistle. Each of these four registers has its own vibratory pattern, its own pitch area (although there is some overlapping), and its own characteristic sound. Arranged by the pitch areas covered, vocal fry is the lowest register, modal voice is next, then falsetto, and finally the whistle register.
The confusion which exists concerning what a register is, and how many registers there are, is due in part to what takes place in the modal register when a person sings from the lowest pitches of that register to the highest pitches. The frequency of vibration of the vocal folds is determined by their length, tension, and mass. As pitch rises, the vocal folds are lengthened, tension increases, and their thickness decreases. In other words, all three of these factors are in a state of flux in the transition from the lowest to the highest tones.
If a singer holds any of these factors constant and interferes with their progressive state of change, his laryngeal function tends to become static and eventually breaks occur, with obvious changes of tone quality. These breaks are often identified as register boundaries or as transition areas between registers. The distinct change or break between registers is called a passaggio or a ponticello. Vocal pedagogists teach that with study a singer can move effortlessly from one register to the other with ease and consistent tone. Registers can even overlap while singing. Teachers who like to use this theory of "blending registers" usually help students through the "passage" from one register to another by hiding their "lift" (where the voice changes).
However, many pedagogists disagree with this distinction of boundaries blaming such breaks on vocal problems which have been created by a static laryngeal adjustment that does not permit the necessary changes to take place. This difference of opinion has effected the different views on vocal registration.