Speech pathologists identify four vocal registers based on the physiology of laryngeal function: the vocal fry register, the modal register, the falsetto register, and the whistle register.
Inhalation is aided by use of external intercostals, scalenes, and sternocleidomastoid muscles. Humans have vocal folds which can loosen, tighten, or change their thickness, and over which breath can be transferred at varying pressures.
The shape of the chest and neck, the position of the tongue, and the tightness of otherwise unrelated muscles can be altered.
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.
Singing is the act of producing musical sounds with the voice and augments regular speech by the use of sustained tonality, rhythm, and a variety of vocal techniques. Singers perform music (arias, recitatives, songs, etc.) that can be sung with or without accompaniment by musical instruments.