View source for Nasalization

{{Short description|Production of a sound while the velum is lowered}}
{{More citations needed|date=June 2010}}
{{Infobox IPA
| above      = Nasalised
| ipa symbol = ◌̃
| ipa number = 424
| decimal1   = 771
}}
{{Sound change}}
{{IPA notice}}
In [[phonetics]], '''nasalisation''' (or '''nasalization''' in [[American English]]) is the production of a sound while the [[soft palate|velum]] is lowered, so that some air escapes through the nose during the production of the sound by the mouth.<ref>{{Cite web |title=nasal {{!}} speech sound |url=https://www.britannica.com/topic/nasal-speech-sound |access-date=2022-07-23 |website=Britannica |language=en}}</ref> An archetypal nasal sound is {{IPA|[n]}}.

In the [[International Phonetic Alphabet]], nasalisation is indicated by printing a [[tilde]] diacritic {{unichar|0303|COMBINING TILDE|html=|cwith=◌}} above the symbol for the sound to be nasalised: {{IPA|[ã]}} is the nasalised equivalent of {{IPA|[a]}}, and {{IPA|[ṽ]}} is the nasalised equivalent of {{IPA|[v]}}. Although not IPA, a subscript diacritic {{IPA|[ą]}}, called an [[ogonek]], is sometimes seen,{{from whom|date=October 2025}} especially when the vowel bears [[tone (linguistics)|tone]] marks that would stack with the superscript tilde. For example, {{angbr IPA|ą̄ ą́ ą̀ ą̂ ą̌}} are more legible than stacked {{angbr IPA|ã̄ ã́ ã̀ ã̂ ã̌}}. The subscript ogonek is also the preferred diacritic for nasalisation by [[Americanist phonetic notation|Americanists]].

==Nasal vowels==
{{main|Nasal vowel}}
Many languages have nasal [[vowel]]s to different degrees, but only a minority of world languages around the world have nasal vowels as contrasting phonemes. That is the case, among others, of [[French language|French]], [[Portuguese language|Portuguese]], [[Hindustani language|Hindustani]], [[Kashmiri language|Kashmiri]], [[Bengali language|Bengali]], [[Nepali language|Nepali]], [[Breton language|Breton]], [[Gheg Albanian]], [[Hmong language|Hmong]], [[Hokkien]], [[Yoruba language|Yoruba]], and [[Cherokee language|Cherokee]]. Those nasal vowels contrast with their corresponding [[oral vowel]]s. Nasality is usually seen as a binary feature, although surface variation in different degrees of nasality caused by neighboring [[nasal consonant]]s has been observed.{{Sfn|Ladefoged|Maddieson|1996|p=298}}

===Degree of nasality===
There are languages, such as in [[Palantla Chinantec]], where vowels seem to exhibit three contrastive degrees of nasality: oral e.g. {{IPA|[e]}} vs lightly nasalised {{IPA|[ẽ]}} vs heavily nasalised {{IPA|[e͌]}};<ref>{{Cite book |first=Juliette |last=Blevins |author-link=Juliette Blevins |url=https://archive.org/details/evolutionaryphon00blev |title=Evolutionary Phonology: The Emergence of Sound Patterns |publisher=Cambridge University Press |year=2004 |isbn=9780521804288 |page=[https://archive.org/details/evolutionaryphon00blev/page/n224 203] |url-access=limited}}</ref><ref>{{Cite book |last=Ladefoged |first=Peter |title=Preliminaries of Linguistic Phonetics |year=1971 |page=35}}</ref> Ladefoged and Maddieson believe that the lightly nasalised vowels are best described as oro-nasal [[diphthong]]s.{{Sfn|Ladefoged|Maddieson|1996|pp=298–299}} Note that Ladefoged and Maddieson's transcription of heavy nasalisation with a double tilde was once ambiguous with the [[extIPA]] use of that diacritic for [[velopharyngeal frication]], though the extIPA has changed its notation to avoid this ambiguity.

==Nasal consonants==
{{main|Nasal consonant}}
By far the most common nasal sounds are [[nasal consonant]]s such as {{IPA|[m]}}, {{IPA|[n]}} or {{IPA|[ŋ]}}. Most nasal consonants are occlusives, and airflow through the mouth is blocked and redirected through the nose. Their oral counterparts are the [[stop consonant|stops]].{{Citation needed|date=June 2019}}

===Nasalised consonants===
Nasalised versions of other consonant sounds also exist but are much rarer than either nasal occlusives or nasal vowels. The [[Middle Chinese]] [[Guangyun|consonant]] [[wikt:日|日]] ({{IPA|[ȵʑ]}}; {{IPA|[ʐ]}} in modern [[Standard Chinese]]) has an odd history; for example, it has evolved into {{IPAblink|ʐ}} and {{IPA|[ɑɻ]}} (or {{IPAblink|ɻ}} and {{IPAblink|ɚ}} respectively, depending on accents) in [[Standard Chinese]]; {{IPAblink|z}}/{{IPAblink|ʑ}} and {{IPAblink|n}} in [[Hokkien]];  {{IPA|[z]}}/{{IPA|[ʑ]}} and {{IPA|[n]}}/{{IPAblink|ɲ|n̠ʲ}} while borrowed into Japan. It seems likely that it was once a nasalized fricative, perhaps a palatal {{IPA|[ʝ̃]}}.

In [[Coatzospan Mixtec]], fricatives and affricates are nasalized before nasal vowels even when they are voiceless. {{citation needed span|In the [[Hupa language|Hupa]], the [[velar nasal]] {{IPA|/ŋ/}} often has the tongue not make full contact, resulting in a nasalized approximant, {{IPA|[ɰ̃]}}.|date=September 2025}} That is [[cognate]] with a [[Nasal palatal approximant|nasalised palatal approximant]] {{IPA|[ȷ̃]}} in other [[Athabaskan languages]].

In [[Umbundu language|Umbundu]], phonemic {{IPA|/ṽ/}} contrasts with the ([[allophone|allophonically]]) nasalised approximant {{IPA|[w̃]}} and so is likely to be a true fricative rather than an approximant.{{Elucidate|date=April 2010}} In [[Old Irish|Old]] and [[Middle Irish]], the [[lenition|lenited]] {{angbr|m}} was a nasalised bilabial fricative {{IPA|[β̃]}}.<ref>{{Cite book |last1=Thurneysen |first1=Rudolf |author-link=Rudolf Thurneysen |title=A Grammar of Old Irish |last2=Binchy |first2=D. A. |publisher=Dublin Institute for Advanced Studies |year=1946 |isbn=1-85500-161-6 |location=Dublin |page=85 |translator-last=Bergin |translator-first=Osborn}}</ref>

[[Ganza language|Ganza]]<ref>{{Cite journal |last=Smolders |first=Joshua |date=2016 |title=A Phonology of Ganza |url=http://journals.dartmouth.edu/cgi-bin/WebObjects/Journals.woa/1/xmlpage/1/document/1070 |format=pdf |journal=Linguistic Discovery |volume=14 |issue=1 |pages=86–144 |doi=10.1349/PS1.1537-0852.A.470 |access-date=2017-01-16 |doi-access=free}}</ref> has a phonemic nasalized [[glottal stop]] {{IPA|[ʔ̃]}} while [[Sundanese language|Sundanese]] has it allophonically; nasalised stops can occur only with pharyngeal articulation or lower, or they would be simple nasals.{{sfn|Ladefoged|Maddieson|1996|p=134}} Nasal [[flap consonant|flaps]] are common allophonically. Many West African languages have a nasal flap {{IPA|[ɾ̃]}} (or {{IPA|[n̆]}}) as an allophone of {{IPAslink|ɾ}} before a nasal vowel; [[voiced retroflex nasal flap]]s are common intervocalic allophones of {{IPAslink|ɳ}} in South Asian languages.

A nasal trill {{IPA|[r̃]}} has been described from some dialects of Romanian, and is posited as an intermediate historical step in [[Rhotacism (sound change)|rhotacism]]. However, the phonetic variation of the sound is considerable, and it is not clear how frequently it is actually trilled.<ref>{{Citation |last=Sampson |first=Rodney |title=Nasal Vowel Evolution in Romance |pages=312–313 |year=1999 |publisher=Oxford University Press |isbn=0-19-823848-7}}</ref> Some languages contrast {{IPA|/r, r̃/}} like [[Toro-tegu Dogon]]<ref>{{Cite book |last=Heath |first=Jeffrey |url=https://deepblue.lib.umich.edu/bitstream/handle/2027.42/123064/A?sequence=4 |title=A Grammar of Toro Tegu (Dogon), Tabi mountain dialect |year=2014}}</ref> and [[Inor_language|Inor]]. A nasal lateral has been reported for some languages, [[Nzema language|Nzema]] contrasts {{IPA|/l, l̃/}},<ref>{{Cite journal |last=Berry |first=J. |date=1955 |title=Some Notes on the Phonology of the Nzema and Ahanta Dialects |journal=Bulletin of the School of Oriental and African Studies |language=en |volume=17 |issue=1 |pages=160–165 |doi=10.1017/S0041977X00106421 |issn=1474-0699 |s2cid=162551544}}</ref> [[Nemi language|Nemi]] contrasts {{IPA|/w, w̥, h, w̃, w̥̃, h̃/}}.

Other languages, such as the [[Khoisan languages]] of [[Khoekhoe language|Khoekhoe]] and [[Gǀui dialect|Gǀui]], as well as several of the [[!Kung language]]s, include [[nasal click]] consonants. Nasal clicks are typically with a nasal or superscript nasal preceding the consonant (for example, velar-dental {{angbr IPA|ŋ͡ǀ}} or {{angbr IPA|ᵑǀ}} and uvular-dental {{angbr IPA|ɴ͡ǀ}} or {{angbr IPA|ᶰǀ}}).{{sfn|Ladefoged|Maddieson|1996|p=268}} Nasalised laterals such as {{IPA|[‖̃]}} (a nasalised lateral alveolar click) are easy to produce but rare or nonexistent as phonemes; nasalised lateral clicks are common in Southern African languages such as [[Zulu language|Zulu]]. Often when {{IPA|/l/}} is nasalised, it becomes {{IPA|[n]}}.

==True nasal fricatives<span class="anchor" id="nareal"></span><span class="anchor" id="Nareal"></span>==
{{Infobox IPA
| above      = Nasal fricative
| ipa symbol = ◌̾
| ipa symbol2 = ◌͋
| ipa number =
| decimal1   =
}}
Besides nasalised oral fricatives, there are true nasal fricatives, or ''anterior nasal fricatives'', previously called ''nareal fricatives''. They are sometimes produced by people with [[Speech disorder|disordered speech]] due to velopharyngeal-port incompetence. The [[turbulence]] in the airflow characteristic of [[fricative]]s is produced not in the mouth but at the [[anterior nasal port]], the narrowest part of the [[nasal cavity]]. (Turbulence can also be produced at the posterior nasal port, or velopharyngeal port, when that port is narrowed &ndash; see [[velopharyngeal fricative]]. With anterior nasal fricatives, the velopharyngeal port is open.) 

An upright tilde is used for this in the [[extensions to the IPA]]: {{IPA|[n̾]}} is a voiced alveolar nasal fricative, with no airflow out of the mouth; this will generally occur when {{IPA|[n]}} is intended. {{IPA|[v̾]}} is an oral fricative with simultaneous nasal frication; this will generally occur when {{IPA|[v]}} is intended.

No known language makes use of nasal fricatives in non-disordered speech.

==Denasalisation==
{{Infobox IPA
| above      = Partially denasalized
| ipa symbol = ◌͊
| ipa number = 654
| decimal1   = 
}}
{{Main|Denasalisation}}
Nasalisation may be lost over time. There are also [[Denasalisation|denasal]] sounds, which sound like nasals spoken with a head cold. They may be found in non-pathological speech as a language loses nasal consonants, as in [[Korean language|Korean]].
{{IPA|[m͊]}} is a sound partway between {{IPA|[m]}} and {{IPA|[b]}}.

==Contextual nasalisation==
Vowels assimilate to surrounding [[nasal consonant]]s in many languages, such as [[Thai language|Thai]], creating nasal vowel allophones. Some languages exhibit a nasalisation of [[Segment (linguistics)|segments]] adjacent to phonemic or allophonic [[nasal vowels]], such as [[Apurinã language|Apurinã]].

Contextual nasalisation can lead to the addition of nasal vowel phonemes to a language.<ref>{{Cite journal |last=Hajek |first=John |year=2013 |title=Vowel Nasalization |url=http://wals.info/chapter/10 |website=WALS Online (v2020.3) [Data set] |doi=10.5281/zenodo.7385533 |editor-last1=Dryer |editor-first1=Matthew S. |editor-last2=Haspelmath |editor-first2=Martin}}</ref> That happened in French, most of whose final consonants disappeared, but its final nasals made the preceding vowels become nasal, which introduced a new distinction into the language. An example is {{lang|fr|vin blanc}} {{IPA|fr|vɛ̃ blɑ̃|}} {{gloss|white wine}}, ultimately from [[Latin]] {{lang|la|vinum}} and {{lang|la|blancum}}.

==See also==
*[[Eclipsis]], a similar process in Gaelic that is often called "nasalisation"
*[[Nasal consonant]]
*[[Nasal release]]
*[[Nasal vowel]]
*[[Nasality (disorder)|Nasality]]
*[[Prenasalised consonant]]

==References==
{{Reflist}}

==Works cited==
* {{SOWL}}

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[[Category:Nasalization| ]]
[[Category:Phonetics]]
[[Category:Phonology]]
[[Category:Historical linguistics]]
[[Category:Assimilation (linguistics)]]