Editing Tone (linguistics) (section)

====Examples====
Tone arose in the [[Athabascan languages]] at least twice, in a patchwork of two systems. In some languages, such as [[Navajo language|Navajo]], syllables with glottalized consonants (including glottal stops) in the [[syllable coda]] developed low tones, whereas in others, such as [[Slavey language|Slavey]], they developed high tones, so that the two tonal systems are almost mirror images of each other. Syllables without glottalized codas developed the opposite tone. For example, high tone in Navajo and low tone in Slavey are due to contrast with the tone triggered by the glottalization.

Other Athabascan languages, namely those in western Alaska (such as [[Koyukon language|Koyukon]]) and the Pacific coast (such as [[Hupa language|Hupa]]), did not develop tone. Thus, the Proto-Athabascan word ''{{IPA|*tuː}}'' ('water') is toneless ''{{IPA|toː}}'' in Hupa, high-tone ''{{IPA|tó}}'' in Navajo, and low-tone ''tù'' in Slavey; while Proto-Athabascan ''{{IPA|*-ɢʊtʼ}}'' ('knee') is toneless ''{{IPA|-ɢotʼ}}'' in Hupa, low-tone ''{{IPA|-ɡòd}}'' in Navajo, and high-tone ''{{IPA|-ɡóʔ}}'' in Slavey. {{Harvcoltxt|Kingston|2005}} provides a phonetic explanation for the opposite development of tone based on the two different ways of producing glottalized consonants with either [[tense voice]] on the preceding vowel, which tends to produce a high [[fundamental frequency]], or [[creaky voice]], which tends to produce a low fundamental frequency. Languages with "stiff" glottalized consonants and tense voice developed high tone on the preceding vowel and those with "slack" glottalized consonants with creaky voice developed low tone.

The [[Bantu languages]] also have "mirror" tone systems in which the languages in the northwest corner of the Bantu area have the opposite tones of other Bantu languages.

Three [[Algonquian languages]] developed tone independently of one another and of neighboring languages: [[Cheyenne language|Cheyenne]], [[Arapaho language|Arapaho]], and [[Kickapoo language|Kickapoo]]. In Cheyenne, tone arose via vowel contraction; the long vowels of Proto-Algonquian contracted into high-pitched vowels in Cheyenne while the short vowels became low-pitched. In Kickapoo, a vowel with a following [h] acquired a low tone, and this tone later extended to all vowels followed by a fricative. In [[Afrikaans]] the glottal fricative also lowers the tone of surrounding vowels.

In [[Mohawk language|Mohawk]], a glottal stop can disappear in a combination of [[morpheme]]s, leaving behind a long falling tone. Note that it has the reverse effect of the postulated rising tone in [[Cantonese]] or [[Middle Chinese]], derived from a lost final glottal stop.

In [[Korean language|Korean]], a 2013 study which compared voice recordings of Seoul speech from 1935 and 2005 found that in recent years, [[Fortis and lenis|lenis consonants]] (ㅂㅈㄷㄱ), [[aspirated consonant]]s (ㅍㅊㅌㅋ) and fortis consonants (ㅃㅉㄸㄲ) were shifting from a distinction via [[voice onset time]] to that of pitch change, and suggests that the modern [[Seoul dialect]] is currently undergoing tonogenesis.<ref>{{cite journal |first1=Yoonjung |last1=Kang|first2=Sungwoo|last2=Han|date=September 2013 |title=Tonogenesis in early Contemporary Seoul Korean: A longitudinal case study|journal=Lingua|volume=134 |pages=62–74|doi=10.1016/j.lingua.2013.06.002}}</ref> These sound shifts still show variations among different speakers, suggesting that the transition is still ongoing.<ref>{{cite journal|first1=Mi-Ryoung |last1=Kim|date=2013|title=Tonogenesis in contemporary Korean with special reference to the onset-tone interaction and the loss of a consonant opposition|journal=The Journal of the Acoustical Society of America |volume=133 |issue=3570 |page=3570|doi=10.1121/1.4806535|bibcode=2013ASAJ..133.3570K}}</ref> Among 141 examined Seoul speakers, these pitch changes were originally initiated by females born in the 1950s, and have almost reached completion in the speech of those born in the 1990s.<ref>{{cite thesis|type=PhD |first1=Sunghye|last1=Cho|date=2017|title=Development of pitch contrast and Seoul Korean intonation|publisher=University of Pennsylvania |url=https://www.researchgate.net/publication/319291457 |archive-url=https://web.archive.org/web/20201029072543/https://www.researchgate.net/profile/Sunghye_Cho2/publication/319291457_Development_of_Pitch_Contrast_and_Seoul_Korean_Intonation_Copyright/links/5d51c9b292851cd046b6c422/Development-of-Pitch-Contrast-and-Seoul-Korean-Intonation-Copyright.pdf|archive-date=October 29, 2020}}</ref>