In linguistics, a register language, also known as a pitch-register language, is a language which combines tone and vowel phonation into a single phonological system. Burmese and the Chinese dialect Shanghainese are examples. Burmese is often considered a tonal language, but differences in relative pitch are correlated with vowel phonation, so that neither exists independently.

There are three such registers in Burmese, which have traditionally been considered three of the four 'tones'. (The fourth is not a tone at all, but a closed syllable, called "entering tone" in translations of Chinese 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.

Burmese pitch-phonation registers

Register	Phonation	Length	Pitch	Example	Gloss
Low	Modal voice	long	low	[làː]	'come'
High	Breathy voice	long	high; falling when final	[lá̤ː] ~ [lâ̤ː]	'mule'
Creaky	Creaky voice	medium	high	[lá̰ˀ]	'moon'
Checked	Final glottal stop	short	high	[lăʔ]	'fresh'

Khmer is sometimes considered to be a register language. It's also been called a "restructured register language" because both its pitch and phonation can be considered allophonic: If they are ignored, the phonemic distinctions they carry remain as a difference in diphthongs and vowel length.

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