In
phonology
Phonology is the branch of linguistics that studies how languages or dialects systematically organize their sounds or, for sign languages, their constituent parts of signs. The term can also refer specifically to the sound or sign system of a ...
, a register, or pitch register, is a
prosodic feature of syllables in certain languages in which
tone, vowel
phonation
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, ''phonation'' is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the defin ...
,
glottalization or similar features depend upon one another.
It occurs in
Burmese,
Vietnamese,
Wu Chinese
The Wu languages (; Wu romanization and IPA: ''wu6 gniu6'' [] ( Shanghainese), ''ng2 gniu6'' [] (Suzhounese), Mandarin pinyin and IPA: ''Wúyǔ'' []) is a major group of Sinitic languages spoken primarily in Shanghai, Zhejiang, Zhejiang Provin ...
and
Zulu.
Burmese
In Burmese, differences in tone correlate with vowel phonation and so neither exists independently. There are three registers in Burmese, which have traditionally been considered three of the four "tones". (The fourth is not actually a register but is a closed syllable, and is similar to the so-called "
entering tone
A checked tone, commonly known by the Chinese calque entering tone, is one of the four syllable types in the phonology of Middle Chinese. Although usually translated as "tone", a checked tone is not a tone in the phonetic sense but rather a syl ...
" in
Middle Chinese
Middle Chinese (formerly known as Ancient Chinese) or the Qieyun system (QYS) is the historical variety of Chinese recorded in the '' Qieyun'', a rime dictionary first published in 601 and followed by several revised and expanded editions. The ...
phonetics.) Jones (1986) views the differences as "resulting from the intersection of both pitch registers and voice registers.... Clearly Burmese is not tonal in the same sense as such other languages and therefore requires a different concept, namely that of pitch register."
Vietnamese
Similarly, several Vietnamese "tones" are largely distinguished by characteristics other than pitch. For example, in Northern Vietnamese, a ''ngã'' syllable is distinguished from the ''sắc'' primarily by the presence of a glottalization in the vowel. The ''nặng'' and ''huyền'' syllables are distinguished primarily by having a short