Vowel harmony

In phonology, vowel harmony is a phonological process in which vowels assimilate to share certain distinctive features. Vowel harmony is often confined to the domain of a phonological word, but may extend across word boundaries in certain languages.
Generally, one vowel will trigger a shift in other vowels within the domain, such that the affected vowels match the relevant feature of the trigger vowel. Intervening segments are common between affected vowels, meaning that the vowels do not need to be next to each other for this change to apply, classifying this as a "long-distance" type of assimilation. Common phonological features that define the natural classes of vowels involved in vowel harmony include vowel backness, vowel height, nasalization, roundedness, and advanced and retracted tongue root.
Certain authors and articles use the term vowel harmony to refer to progressive vowel assimilation, and use umlaut to refer to regressive assimilation. The term umlaut is also used in a different sense to refer to a type of vowel gradation, as well as the diacritic that often marks such changes. Metaphony is often used synonymously with vowel harmony, but is typically used to describe historical sound changes. This article uses the term "vowel harmony" to refer to both progressive and regressive assimilatory processes.
Vowel harmony is found in many agglutinative languages. The given domain of vowel harmony taking effect often spans across morpheme boundaries, and suffixes and prefixes will usually follow vowel harmony rules. Vowel harmony is also considered an areal feature in some parts of the world, especially Northern and Central Asia among the Turkic, Mongolic and Tungusic language families, as well as other languages in contact with languages from the aforementioned families.

"Long-distance"

Vowel harmony processes are "long-distance" in the sense that the assimilation involves sounds that are separated by intervening segments. In other words, harmony refers to the assimilation of sounds that are not adjacent to each other. For example, a vowel at the beginning of a word can trigger assimilation in a vowel at the end of a word. The assimilation occurs across the entire word in many languages. This is represented schematically in the following diagram:
In the diagram above, the V_a causes the following V_b to assimilate and become the same type of vowel.
The vowel that causes the vowel assimilation is frequently termed the trigger while the vowels that assimilate are termed targets. When the vowel triggers lie within the root or stem of a word and the affixes contain the targets, this is called stem-controlled vowel harmony. This is fairly common among languages with vowel harmony and may be seen in the Hungarian dative suffix:
The dative suffix has two different forms -nak/-nek. The -nak form appears after the root with back vowels. The -nek form appears after the root with front vowels.

Features of vowel harmony

Vowel harmony often involves dimensions such as:

Rose & Walker	Ko	Dimension	Value
Backness Harmony	Palatal harmony	Vowel backness	back or front,
Roundedness Harmony	Labial harmony	Roundedness	rounded or unrounded,
Height Harmony	Height harmony	Vowel height	high or low,
Tongue Root Harmony	Tongue root harmony	Advanced and retracted tongue root	advanced or retracted,

Nasalization '
Rhoticity, like in Yurok.
Unconventional systems, like the one in Nez Perce, that do not seem to be based on any obvious phonetic feature at first.

In many languages, vowels can be said to belong to particular sets or classes, such as back vowels or rounded vowels. Some languages have more than one system of harmony. For instance, Altaic languages are proposed to have a rounding harmony superimposed over a backness harmony.
Even among languages with vowel harmony, not all vowels need to participate in the vowel conversions; these vowels are termed neutral. Neutral vowels may be opaque and block harmonic processes or they may be transparent and not affect them. Intervening consonants are also often transparent.
Finally, languages that do have vowel harmony often allow for lexical disharmony, or words with mixed sets of vowels even when an opaque neutral vowel is not involved. Van der Hulst & van de Weijer point to two such situations: polysyllabic trigger morphemes may contain non-neutral vowels from opposite harmonic sets and certain target morphemes simply fail to harmonize. Many loanwords exhibit disharmony. For example, Turkish vakit, ; *vakı'''t would have been expected. Other examples from Finnish include olympialaiset and sekundäärinen which have both front and back vowels. In standard Finnish, these words are pronounced as they are spelled, but many speakers intuitively apply vowel harmony – olumpialaiset, and sekundaarinen or sekyndäärinen.

Languages with vowel harmony

Turkic languages

Turkic languages inherit their systems of vowel harmony from Proto-Turkic, which already had a fully developed system. The one exception is Uzbek, which has lost its vowel harmony due to extensive Persian influence; however, its closest relative, Uyghur, has retained Turkic vowel harmony.

Azerbaijani

Azerbaijani's system of vowel harmony has both front/back and rounded/unrounded vowels.

Tatar

Tatar has no neutral vowels. The vowel é is found only in loanwords. Other vowels also could be found in loanwords, but they are seen as Back vowels. Tatar language also has a rounding harmony, but it is not represented in writing. O and ö could be written only in the first syllable, but vowels they mark could be pronounced in the place where ı and e are written.

Kazakh

Kazakh's system of vowel harmony is primarily a front/back system, but there is also a system of rounding harmony that is not represented by the orthography.

Kyrgyz

Kyrgyz's system of vowel harmony is primarily a front/back system, but there is also a system of rounding harmony, which strongly resembles that of Kazakh.

Turkish

Turkish has a 2-dimensional vowel harmony system, where vowels are characterised by two features: and . There are two sets of vocal harmony systems: a simple one and a complex one. The simple one is concerned with the low vowels e, a and has only the feature. The complex one is concerned with the high vowels i, ü, ı, u and has both and features. The close-mid vowels ö, o are not involved in vowel harmony processes.

Front/back harmony

Turkish has two classes of vowelsfront and back. Vowel harmony states that words may not contain both front and back vowels. Therefore, most grammatical suffixes come in front and back forms, e.g. Türkiye'de "in Turkey" but Almanya'da "in Germany".

Nom.sg	Gen.sg.	Nom.pl	Gen.pl.	Gloss
ip	ipin	ipler	iplerin	'rope'
el	elin	eller	ellerin	'hand'
kız	kızın	kızlar	kızların	'girl'

Rounding harmony

In addition, there is a secondary rule that i and ı in suffixes tend to become ü and u respectively after rounded vowels, so certain suffixes have additional forms. This gives constructions such as Türkiye'dir "it is Turkey", kapıdır "it is the door", but gündür "it is the day", karpuzdur "it is the watermelon".

Exceptions

Not all suffixes obey vowel harmony perfectly.
In the suffix -yor, the o is invariant, while the i changes according to the preceding vowel; for example sönüy'or – "he/she/it fades". Likewise, in the suffix -ken, the e is invariant: Roma'dayke'n – "When in Rome"; and so is the i in the suffix -ebil: inanılab'ilir – "credible". The suffix -ki exhibits partial harmony, never taking a back vowel but allowing only the front-voweled variant -kü: dünkü' – "belonging to yesterday"; yarınki – "belonging to tomorrow".
Most Turkish words do not only have vowel harmony for suffixes, but also internally. However, there are many exceptions.
Compound words are considered separate words with respect to vowel harmony: vowels do not have to harmonize between members of the compound. Vowel harmony does not apply for loanwords, as in otobüs – from French "autobus". There are also a few native modern Turkish words that do not follow the rule. However, in such words, suffixes nevertheless harmonize with the final vowel; thus annesi – "his/her mother", and voleybolcu – "volleyballer".
In some loanwords the final vowel is an a, o or u and thus looks like a back vowel, but is phonetically actually a front vowel, and governs vowel harmony accordingly. An example is the word saat, meaning "hour" or "clock", a loanword from Arabic. Its plural is saatler. This is not truly an exception to vowel harmony itself; rather, it is an exception to the rule that a denotes a front vowel.
Disharmony tends to disappear through analogy, especially within loanwords; e.g. Hüsnü < earlier Hüsni, from Arabic ; Müslüman "Moslem, Muslim " < Ottoman Turkish, from Persian.

Tuvan

Tuvan has one of the most complete systems of vowel harmony among the Turkic languages.

Mongolic languages

Mongolic languages display various vowel harmony systems. While there is some debate, Proto-Mongolic appears to have had a system of backness harmony, from which the modern languages' systems descend.

Mongolian

Mongolian innovates on Proto-Mongolic's system, exhibiting both tongue root harmony and rounding harmony. The tongue root harmony involves the vowels: and . The vowel is phonetically similar to the -RTR vowels, but is largely transparent to vowel harmony. Rounding harmony only affects the open vowels,. Some sources refer to the primary harmonization dimension as pharyngealization or palatalness, but neither of these is technically correct. Likewise, referring to ±RTR as the sole defining feature of vowel categories in Mongolian is not fully accurate either. In any case, the two vowel categories differ primarily with regards to tongue root position, and ±RTR is a convenient and fairly accurate descriptor for the articulatory parameters involved.

-RTR	э	ү	ө	и
+RTR	а	у	о	-

Kalmyk-Oirat

Kalmyk Oirat, a western Mongolic language, displays very clear backness harmony. Words may only contain back or front vowels, but may be rounded or unrounded. /y/ alternates with /u/, /ø/ alternates with /o/, /æ/ alternates with /a/, and /i/ has the allophonic alternation in suffixes. /e/ is mostly transparent to vowel harmony.

Korean

Korean is an example of a language with a vowel harmony system that is gradually becoming less productive. While Middle Korean had strong vowel harmony, modern Korean only retains it in certain cases such as onomatopoeia, adjectives, adverbs, conjugation, and interjections. Many native Korean words demonstrate the formerly productive vowel harmony, such as 사람 and 부엌.
The current system of Korean vowel harmony is based on the orthographic system where vowels are classified as either positive/light, negative/dark, or neutral. Many scholars treat the positive vowels as +RTR and the negative and neutral vowels as −RTR. The basic conjugations for Korean's tenses demonstrate this vowel harmony, using the +RTR vowel /a/ or −RTR vowel /ʌ/ depending on the last vowel of the verb/adjective stem.
Note that the vowel harmony does not spread to subsequent morphemes, such as the polite ending 요, which uses a +RTR vowel, but occurs the same on words that take the +RTR tense marker.

Persian

Persian is a language which includes various types of regressive and progressive vowel harmony in different words and expressions.
In Persian, progressive vowel harmony only applies to prepositions/post-positions when attached to pronouns.

Preposition/Post-Position	Pronoun	Result
Be	man	Behem
Az	man	Azam
Ba	man	Baham
Ra	man	Mara
	to	Toro

In Persian, regressive vowel harmony, some features spread from the triggering non-initial vowel to the target vowel in the previous syllable. The application and non-application of this backness harmony which can also be considered rounding harmony.

Verb	Result of Rounding Harmony
Be-do	Bodo
Be-kon	Bokon
Be-ro	Boro
Be-kosh	Bokosh

Uralic languages

Many, though not all, Uralic languages show vowel harmony between front and back vowels. Vowel harmony is often hypothesized to have existed in Proto-Uralic, though its original scope remains a matter of discussion.

Samoyedic

Vowel harmony is found in Nganasan and is reconstructed also for Proto-Samoyedic.

Hungarian

Vowel types

Hungarian has a system of front, back, and intermediate vowels and some vowel harmony processes. The basic rule is that words including at least one back vowel get back vowel suffixes, while words excluding back vowels get front vowel suffixes. Single-vowel words which have only the neutral vowels are unpredictable, but e takes a front-vowel suffix.

Front	e	é	i	í	ö	ő	ü	ű
Back	a	á	-	-	o	ó	u	ú

Vowel length

In Hungarian language there are long, and short vowels

There are long, and short vowel pairs which are indicated using accents in writing in all but four exceptions with the exceptions possibly be either long, or short as well
The four exceptions are a, á, e, é

Long vowels compared to short ones are quite simply voiced for a longer period of time. Hungarian long vowels are two units long compared to other Uralic language Finnish's three units long vowels. In order for two vowels to be long-short pairs, the long vowel pronounced short must be identical to its short pair, and vice-versa. In the case of the four exceptions, this is not applicable because - contrary to their written form - the four exceptions are not two pairs of long, and short vowels, but vowels with pronunciation difference that is not only the length
In writing the long of such vowel pairs are marked with stick-like accents most of the time compared to its dot-accented, or non-accented versions

For example papír is often pronounced instead of

In the four exceptions case the stick-like accent refer to long length most if not all the timeNote - while stick like accents mark long - double dot, and double stick accents mark cleft lip pronunciation
In practice these long and short vowels sometimes lengthen, or shorten due to agglutinations. Most if not all the time this change is with written difference

híd - hidak - in this case the pronunciation is according to the words are written

It can happen that an exceptional vowel is gaining, or losing an accent regardless of it not being the long, or the short pair of the other

fél - felek - in this case the pronunciation is according to the words are written, yet these are not long, and short pairs
fa - fák - in this case the pronunciation is according to the words are written, yet these are not short, and long pairs
Vowel cleft lipness

There are cleft lip, and non-cleft lip vowel pairs. Cleft lip vowels approach sound when pronounced compared to its non-cleft lip vowel pairs. All these letters other than e, and é are marked with double accents

For example ö is the short cleft lip version, while ő is the long cleft lip version of o

Words with such sounds are often agglutinated using cleft lip vowels also

okos + kd = okoskodó
* Non-cleft lip vowel of root word to non-cleft lip vowel in agglutination
hős + kd = hősködő
* Cleft lip vowel of root word to cleft lip vowel in agglutination
daru + z = daruzó
* Non-cleft lip vowel of root word to non-cleft lip vowel in agglutination
hegedű + z = hegedűző
* Cleft lip vowel of root word to cleft lip vowel in agglutination

Naturally since e, and é are also cleft lip with these as the last vowel of a word the following examples are also valid

foci + z = focizó
* Non-cleft lip vowel of root word to non-cleft lip vowel in agglutination
tévé + z = tévéző
* Cleft lip vowel of root word to cleft lip vowel in agglutination
ló + vgl = lovagló
* Non-cleft lip vowel of root word to non-cleft lip vowel in agglutination
teve + vgl = tevegelő
* Cleft lip vowel of root word to cleft lip vowel in agglutinationNote that "vgl" is not considered an agglutination, but in the camel's case it is used as one. "To ride" means lovagol, in which "o", and "l" are supposed to switch places. Lovag means knight, and "to ride a horse" is "to pretend to be a knight" rather in Hungarian language, but in the word for camel there is a "v", and it is very in a convenient place there. The word for knight is maybe related to the word for horse in Hungarian language

''Note that all these examples here are adjectives, and not very translatable''
Behaviour of neutral vowels

Unrounded front vowels can occur together with either back vowels or rounded front vowels, but rounded front vowels and back vowels can occur together only in words of foreign origins. The basic rule is that words including at least one back vowel take back vowel suffixes, while words excluding back vowels usually take front vowel suffixes.
Some other rules and guidelines to consider:

Compound words get suffix according to the last word, e.g.: ártér compound of ár + tér front vowel suffix just as the word tér when stands alone
In case of words of obvious foreign origins: only the last vowel counts : sofőrhöz, nüanszszal, generál'ás, októbe'rben, parlamentben, szoftverrel
* If the last vowel of the foreign word is i or í, then the last but one vowel will be taken into consideration, e.g. papírhoz, Rashiddal. If the foreign word includes only the vowels i or í then it gets front vowel suffix, e.g.: Mitch-nek
* There are some non-Hungarian geographical names that have no vowels at all, in which case as the word does not include back vowel, it gets front vowel suffix
For acronyms: the last vowel counts, e.g.: HR gets front vowel suffix as the last pronounced vowel is front vowel
Some 1-syllable Hungarian words with i, í or é are strictly using front suffixes, while some others can take back suffixes only
Some foreign words that have fit to the Hungarian language and start with back vowel and end with front vowel can take either front or back suffixes : farmerban or farmerben
Suffixes with multiple forms

Grammatical suffixes in Hungarian can have one, two, three, or four forms:one form: every word gets the same suffix regardless of the included vowels two forms : words get either back vowel or front vowel suffix three forms: there is one back vowel form and two front vowel forms; one for words whose last vowel is rounded front vowel and one for words whose last vowel is not rounded front vowel four forms: there are two back vowel forms and two front vowel forms
An example on basic numerals:

Agglutination vowel constraints

Hungarian language is a consonant oriented language that makes vowel harmony possible, but the vowels in agglutinations can not be changed according to free will. Some of such vowels even change the meaning of the word

For this reason the vowels in agglutinations are constrained seemingly arbitrary

For example it was mentioned that the last cleft lip vowel in the root of the word induces an agglutination with also at least one cleft lip vowel in it, however this is not always the case due to certain agglutinations are constrained. One good example is the -kor agglutination that can not take any other vowel, but oötöt - in accusative case the vowel before t is not as constrainedötkor - in this case o vowel is constrained not to be cleft lipegykor - in this case o vowel is constrained not to be frontal, and not to be cleft lip
There are further examples of vowel constraints in agglutinations not only for cleft lip-ness with some agglutination possessing

only one
only two
only three
or more forms

The vowel in these forms are only short, or only long

Generally speaking an agglutination with a given meaning - or even a given context of meanings - may only possess either a long, or a short vowel throughout its forms regarding constraints

In the following examples the used vowels in the agglutinations change the meaning

tévé + zk = tévézek - i am watching tv
tévé + zk = tévézik - he is watching tv
tévé + zk = tévézők - people who are watching tv

As you can see in the last example's agglutination of tévézők is with long vowel. This resulted in a noun, not a verb. The long vowel renders meaning completely detached of the other two examples' context. The other two are in a context with only short vowels, with the rest of their context is the following:

tévé + zl = tévézel - you are watching tv
* Agglutination -zel is with short vowel
tévé + ztk = tévéztek - you are watching tv
* Agglutination -ztek is with short vowel
tévé + znk = tévézünk - we are watching tv
* Agglutination -zünk is with short vowel
tévé + znk = tévéznek - they are watching tv
* Agglutination -znek is with short vowel

Likewise using the same agglutination used to tévézők, the word utazók is also with long vowel, that is also a noun against utazok with a short vowel that is likewise a '''verb'''

Mansi

Vowel harmony occurred in Southern Mansi.

Khanty

In the Khanty language, vowel harmony occurs in the Eastern dialects, and affects both inflectional and derivational suffixes. The Vakh-Vasyugan dialect has a particularly extensive system of vowel harmony:

Front
Back

Front
Back

Trigger vowels occur in the first syllable of a word, and control the backness of the entire word. Target vowels are affected by vowel harmony and are arranged in seven front-back pairs of similar height and roundedness, which are assigned the archiphonemes A, O, U, I, Ɪ, Ʊ.
The vowels, and appear only in the first syllable of a word, and are thus strictly trigger vowels. All other vowel qualities may act in both roles.
Vowel harmony is lost in the Northern and Southern dialects, as well as in the Surgut dialect of Eastern Khanty.

Mari

Most varieties of the Mari language have vowel harmony.

Erzya

The Erzya language has a limited system of vowel harmony, involving only two vowel phonemes: versus .
Moksha, the closest relative of Erzya, has no phonemic vowel harmony, though has front and back allophones in a distribution similar to the vowel harmony in Erzya.

Finnic languages

Vowel harmony is found in most of the Finnic languages. It has been lost in Livonian and in Standard Estonian, where the front vowels ü ''ä ö'' occur only in the first syllable. [South Estonian language|Estonian language|South Estonian] Võro language as well as some Estonian dialects, however, retain vowel harmony.

Finnish

In the Finnish language, there are three classes of vowelsfront, back, and neutral, where each front vowel has a back vowel pairing. Grammatical endings such as case and derivational endingsbut not encliticshave only archiphonemic vowels U, O, A, which are realized as either back or front inside a single word. From vowel harmony it follows that the initial syllable of each single word controls the frontness or backness of the entire word. Non-initially, the neutral vowels are transparent to and unaffected by vowel harmony. In the initial syllable:

a back vowel causes all non-initial syllables to be realized with back vowels, e.g. pos+ahta+a → posahtaa
a front vowel causes all non-initial syllables to be realized with front vowels, e.g. räj+ahta+a → räjähtää.
a neutral vowel acts like a front vowel, but does not control the frontness or backness of the word: if there are back vowels in non-initial syllables, the word acts like it began with back vowels, even if they come from derivational endings, e.g. sih+ahta+a → sihahtaa cf. sih+ise+a → sihistä.

For example:

kaura begins with back vowel → kauralla
kuori begins with back vowel → kuorella
sieni begins without back vowels → sienellä
käyrä begins without back vowels → käyrällä
tuote begins with back vowels → tuotteessa
kerä begins with a neutral vowel → kerällä
kera begins with a neutral vowel, but has a noninitial back vowel → keralla

Some dialects that have a sound change opening diphthong codas also permit archiphonemic vowels in the initial syllable. For example, standard 'ie' is reflected as 'ia' or 'iä', controlled by noninitial syllables, in the Tampere dialect, e.g. tiä ← tie but miakka ← miekka
... as evidenced by tuotteessa. Even if phonologically front vowels precede the suffix -nsa, grammatically it is preceded by a word controlled by a back vowel. As shown in the examples, neutral vowels make the system unsymmetrical, as they are front vowels phonologically, but leave the front/back control to any grammatical front or back vowels. There is little or no change in the actual vowel quality of the neutral vowels.
As a consequence, Finnish speakers often have problems with pronouncing foreign words which do not obey vowel harmony. For example, olympia is often pronounced olumpia. The position of some loans is unstandardized or ill-standardized. Where a foreign word violates vowel harmony by not using front vowels because it begins with a neutral vowel, then last syllable generally counts, although this rule is irregularly followed. Experiments indicate that e.g. miljonääri always becomes miljonääriä, but marttyyri becomes equally frequently both marttyyria and marttyyriä, even by the same speaker.
With respect to vowel harmony, compound words can be considered separate words. For example, syyskuu has both u and y, but it consists of two words syys and kuu, and declines syys·kuu·ta. The same goes for enclitics, e.g. taaksepäin "backwards" consists of the word taakse "to back" and -päin "-wards", which gives e.g. taaksepäinkään. If fusion takes place, the vowel is harmonized by some speakers, e.g. tälläinen pro tällainen ← tämän lainen.
Some Finnish words whose stems contain only neutral vowels exhibit an alternating pattern in terms of vowel harmony when inflected or forming new words through derivation. Examples include meri "sea", meressä "in the sea", but merta, not *mertä; veri "blood", verestä "from the blood", but verta, not *vertä; pelätä "to be afraid", but pelko "fear", not *pelkö; kipu "pain", but kipeä "sore", not *kipea.
Helsinki slang has slang words that have roots violating vowel harmony, e.g. Sörkka. This can be interpreted as Swedish influence.

Veps

The Veps language has partially lost vowel harmony.

Yokuts

Vowel harmony is present in all Yokutsan languages and dialects. For instance, Yawelmani has 4 vowels. These can be grouped as in the table below.

	Unrounded	Rounded
High
Low

Vowels in suffixes must harmonize with either or its non- counterparts or with or non- counterparts. For example, the vowel in the aorist suffix appears as when it follows a in the root, but when it follows all other vowels it appears as. Similarly, the vowel in the nondirective gerundial suffix appears as when it follows an in the root; otherwise it appears as.

Word	IPA	Comment
-hun/-hin
muṭhun		'swear '
giy̓hin		'touch '
gophin		'take of infant '
xathin		'eat '
-tow/-taw
goptow		'take care of infant '
giy̓taw		'touch '
muṭtaw		'swear '
xattaw		'eat '

In addition to the harmony found in suffixes, there is a harmony restriction on word stems where in stems with more than one syllable all vowels are required to be of the same lip rounding and tongue height dimensions. For example, a stem must contain all high rounded vowels or all low rounded vowels, etc. This restriction is further complicated by long high vowels being lowered and an epenthetic vowel which does not harmonize with stem vowels.

Sumerian

There is some evidence for vowel harmony according to vowel height or ATR in the prefix i₃/e- in inscriptions from pre-Sargonic Lagash Many cases of partial or complete assimilation of the vowel of certain prefixes and suffixes to one in the adjacent syllable are reflected in writing in some of the later periods, and there is a noticeable though not absolute tendency for disyllabic stems to have the same vowel in both syllables. What appears to be vowel contraction in hiatus is also very common.

Other languages

Vowel harmony occurs to some degree in many other languages, such as

Several dialects of Arabic including:
* Palestinian Arabic
* Iraqi Arabic
* Lebanese Arabic
Akan languages
Assamese
Australian Aboriginal languages
* Jingulu
* Warlpiri
Assyrian Neo-Aramaic
Several Bantu languages such as:
* Standard Lingala
* Kgalagadi
* Malila
* Phuthi
*Shona
* Southern Sotho
* Northern Sotho
* Tswana
Bezhta
Some Chadic languages, such as Buwal
Chukchi
Coeur d'Alene
Coosan languages
Dusunic languages
Iberian languages
* Astur-Leonese
* Galician and Portuguese dialects
* Catalan/Valencian
* Eastern Andalusian Spanish
* Murcian Spanish
Igbo
Italo-Romance languages: several Swiss Italian dialects.
Japanese language - in some of the Kansai dialects. Additionally, some consider that vowel harmony must have existed at one time in Old Japanese, though there is no broad consensus. See the pertinent.
Maiduan languages
Nez Percé
Nilotic languages
Qiang
Buchan Scots is a Scots dialect with vowel height harmony, compare "hairy", "really". This effect is blocked by voiced obstruents and certain consonant clusters: "baby", "lumpy".
Somali
Takelma
Telugu
Several Tibetic languages, including Lhasa Tibetan
Tungusic languages, such as Manchu
Utian languages
Urhobo
Yurok

Other types of harmony

Although vowel harmony is the most well-known harmony, not all types of harmony that occur in the world's languages involve only vowels. Other types of harmony involve consonants. Rarer types of harmony are those that involve tone or both vowels and consonants.

Vowel–consonant harmony

Some languages have harmony processes that involve an interaction between vowels and consonants. For example, Chilcotin has a phonological process known as vowel flattening where vowels must harmonize with uvular and pharyngealized consonants.
Chilcotin has two classes of vowels:

"flat" vowels
non-"flat" vowels

Additionally, Chilcotin has a class of pharyngealized "flat" consonants. Whenever a consonant of this class occurs in a word, all preceding vowels must be flat vowels.
If flat consonants do not occur in a word, then all vowels will be of the non-flat class:
Other languages of this region of North America, such as St'át'imcets, have similar vowel–consonant harmonic processes.

Syllabic synharmony

Syllabic synharmony was a process in the Proto-Slavic language ancestral to all modern Slavic languages. It refers to the tendency of frontness to be generalised across an entire syllable. It was therefore a form of consonant–vowel harmony in which the property 'palatal' or 'non-palatal' applied to an entire syllable at once rather than to each sound individually.
The result was that back vowels were fronted after j or a palatal consonant, and consonants were palatalised before j or a front vowel. Diphthongs were harmonized as well, although they were soon monophthongized because of a tendency to end syllables with a vowel. This rule remained in place for a long time, and ensured that a syllable containing a front vowel always began with a palatal consonant, and a syllable containing j was always preceded by a palatal consonant and followed by a front vowel.
A similar process occurs in Skolt Sami, where palatalization of consonants and fronting of vowels is a suprasegmental process applying to a whole syllable. Suprasegmental palatalization is marked with the letter ʹ, which is a Modifier letter prime, for example in the word vääʹrr 'mountain, hill'.

Rhotic harmony

The Mawo dialect of Northern Qiang displays rhotic harmony, where vowels must align with the previous vowel's rhoticity.

Unconventional systems

Languages such as Nez Perce and Chukchi have vowel harmony systems which can not be easily explained in terms of height, backness, tongue root, or rounding. In Nez Perce, Katherine Nelson proposes that the two sets of vowels be considered as distinct "triangles" of vowel space, each by themselves maximally dispersed, where one set is somewhat retracted in comparison to the dominant. Note here that can behave as a dominant or recessive vowel depending on the root it is in; it is not transparent to vowel harmony.