In linguistics, a register language is a language which combines tone and vowel phonation into a single phonological system. Burmese and Cambodian are examples. Burmese is usually considered a tonal language and Cambodian a vowel-phonation language, but in both cases differences in relative pitch are correlated with vowel phonation, so that neither exists independently. Linguistics is the scientific study of human language, and someone who engages in this study is called a linguist or linguistician. ... This article or section uses Ruby annotation. ... Phoneticians define phonation as use of the laryngeal system to generate an audible source of acoustic energy, i. ... Phonology (Greek phone = voice/sound and logos = word/speech), is a subfield of linguistics closely associated with phonetics. ...

There are three or four vowel registers in Burmese. They are:

Even if the last is considered to have a final consonant rather than a vowel register, the other three are distinguished by both pitch and phonation together rather than independently. Breathy voice or murmured voice is a phonation in which the vocal folds are vibrating as in normal voicing, but the glottal closure is incomplete, so that the voicing is somewhat inefficient and air continues to leak between the vocal folds throughout the vibration cycle with audible friction noise. ... Creaky voice (also called laryngealisation or vocal fry, especially in the US), is a special kind of phonation in which the arytenoid cartilages in the larynx are drawn together; as a result, the vocal folds are compressed rather tightly, becoming relatively slack and compact, and forming a large, irregularly vibrating... The glottal stop or voiceless glottal plosive is a type of consonantal sound, used in many spoken languages. ...