Editing Tone (linguistics) (section)

====Triggers of tonogenesis====

{{More citations needed section|date=July 2020}}

"There is tonogenetic potential in various series of phonemes: glottalized vs. plain consonants, unvoiced vs. voiced, aspirated vs. unaspirated, geminates vs. simple (...), and even among vowels".{{sfnp|Michaud|Sands|2020}} Very often, tone arises as an effect of the [[Phonological change#Loss|loss]] or [[Phonological change#Merger|merger]] of consonants. In a nontonal language, [[voiced consonant]]s commonly cause following vowels to be pronounced at a lower pitch than other consonants. That is usually a minor phonetic detail of voicing. However, if consonant voicing is subsequently lost, that incidental pitch difference may be left over to carry the distinction that the voicing previously carried (a process called [[transphonologization]]) and thus becomes meaningful ([[Phonemic contrast|phonemic]]).{{sfnp|Kingston|2011|pp=2304–2310}}

This process happened in the [[Punjabi language]]: the Punjabi [[breathy voice|murmured]] (voiced aspirate) consonants have disappeared and left tone in their wake. If the murmured consonant was at the beginning of a word, it left behind a low tone; at the end, it left behind a high tone. If there was no such consonant, the pitch was unaffected; however, the unaffected words are limited in pitch and did not interfere with the low and high tones. That produced a tone of its own, mid tone. The historical connection is so regular that Punjabi is still written as if it had murmured consonants, and tone is not marked. The written consonants tell the reader which tone to use.{{sfnp|Bhatia|1975}}

Similarly, final [[fricative]]s or other consonants may phonetically affect the pitch of preceding vowels, and if they then [[lenition|weaken]] to {{IPA|[h]}} and finally disappear completely, the difference in pitch, now a true difference in tone, carries on in their stead.{{sfnp|Kingston|2011|pp=2310–2314}} This was the case with Chinese. Two of the three tones of [[Middle Chinese]], the "rising" and the "departing" tones, arose as the [[Old Chinese]] final consonants {{IPA|/ʔ/}} and {{IPA|/s/ → /h/}} disappeared, while syllables that ended with neither of these consonants were interpreted as carrying the third tone, "even". Most varieties descending from Middle Chinese were further affected by a [[tone split]] in which each tone divided in two depending on whether the initial consonant was voiced. Vowels following a voiced consonant ([[depressor consonant]]) acquired a lower tone as the voicing lost its distinctiveness.{{sfnp|Kingston|2011|p=2311}}

The same changes affected many other languages in the same area, and at around the same time (AD 1000–1500). The tone split, for example, also occurred in [[Thai language|Thai]] and [[Vietnamese language|Vietnamese]].

In general, voiced initial consonants lead to low tones while vowels after aspirated consonants acquire a high tone. When final consonants are lost, a glottal stop tends to leave a preceding vowel with a high or rising tone (although glottalized vowels tend to be low tone so if the glottal stop causes vowel glottalization, that will tend to leave behind a low vowel). A final fricative tends to leave a preceding vowel with a low or falling tone. Vowel phonation also frequently develops into tone, as can be seen in the case of Burmese.