A nasal vowel is a

vowel A vowel is a speech sound pronounced without any stricture in the vocal tract, forming the nucleus of a syllable. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness a ...

that is produced with a lowering of the soft palate (or velum) so that the air flow escapes through the nose and the

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

simultaneously, as in the French vowel /ɑ̃/ () or Amoy []. By contrast, oral vowels are produced without nasalization. Nasalized vowels are vowels under the influence of neighbouring sounds. For instance, the [] of the word ''hand'' is affected by the following nasal consonant. In most languages, vowels adjacent to nasal consonants are produced partially or fully with a lowered velum in a natural process of assimilation and are therefore technically nasal, but few speakers would notice. That is the case in English: vowels preceding nasal consonants are nasalized, but there is no phonemic distinction between nasal and oral vowels, and all vowels are considered phonemically oral. Some languages contrast oral vowels and nasalized vowels phonemically. Linguists make use of minimal pairs to decide whether or not the nasality is of linguistic importance. In French, for instance, nasal vowels are distinct from oral vowels, and words can differ by the vowel quality. The words ''beau'' "beautiful" and ''bon'' "good" are a minimal pair that contrasts primarily the vowel nasalization even though the from ''bon'' is slightly more open. Portuguese allows nasal diphthongs, which contrast with their oral counterparts, like the pair ''mau'' "bad" and ''mão'' "hand". Although there are French loanwords in English with nasal vowels like ''croissant'' [], there is no expectation that an English-speaker would nasalize the vowels to the same extent as French-speakers or Portuguese-speakers. Likewise, pronunciation keys in English dictionaries do not always indicate nasalization of French or Portuguese loanwords.

Influence on vowel height

Nasalization as a result of the assimilation of a nasal consonant tends to cause a raising of vowel height; phonemically distinctive nasalization tends to lower the vowel. According to a different assessment, high vowels do tend to be lowered, but low vowels tend to be raised instead. In most languages, vowels of all heights are nasalized indiscriminately, but preference occurs in some languages, such as for high vowels in Chamorro and low vowels in Thai.

Degree of nasalization

A few languages, such as Palantla Chinantec, contrast lightly nasalized and heavily nasalized vowels. They may be contrasted in print by doubling the IPA diacritic for nasalization: vs . Bickford & Floyd (2006) combine the tilde with the

ogonek The tail or ( ; Polish: , "little tail", diminutive of ) is a diacritic hook placed under the lower right corner of a vowel in the Latin alphabet used in several European languages, and directly under a vowel in several Native American langu ...

: vs . (The ogonek is sometimes used in an otherwise IPA transcription to avoid conflict with tone diacritics above the vowels.)

Origin

Rodney Sampson described a three-stage historical account, explaining the origin of nasal vowels in modern French. The notation of Terry and Webb is used below, where V, N, and Ṽ (with a tilde above) represent oral vowel, nasal consonant, and nasal vowel, respectively.Terry, Kristen Kennedy & Webb, Eric Russell. (2011). Modeling the emergence of a typological anomaly: Vowel nasalization in French. In ''Annual Meeting of the Berkeley Linguistics Society, 37''(1), 155–169. In the

Old French Old French (, , ; ) was the language spoken in most of the northern half of France approximately between the late 8th regressive assimilation, as VN > ṼN. In the Middle French">Assimilation (phonology)">regressive assimilation, as VN > ṼN. In the Middle French period, the realization of the nasal consonant became variable, as VN > Ṽ(N). As the language evolves into its modern form, the consonant is no longer realized, as ṼN > Ṽ.

Orthography

Languages written with Latin script may indicate nasal vowels by a trailing Silent letter, silent ''n'' or ''m'', as is the case in French, Portuguese, Lombard language, Lombard (central classic orthography), Bambara language, Bamana, Breton language, Breton, and Yoruba. In other cases, they are indicated by diacritics. In the

International Phonetic Alphabet The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standard written representation ...

, nasal vowels are denoted by a tilde over the symbol for the vowel. The same practice can be found in Portuguese marking with a tilde in diphthongs (e.g. ''põe'') and for words ending in /ɐ̃/ (e.g. ''manhã'', ''irmã''). While the tilde is also used for this purpose in Paraguayan Guaraní, phonemic nasality is indicated by a diaeresis ( ¨ ) in the standardized orthographies of most varieties of Tupí-Guaraní spoken in

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

. Polish, Navajo, and Elfdalian use a hook under the letter, called an

, as in ''ą, ę''. The Pe̍h-ōe-jī romanization of Taiwanese Hokkien and Amoy uses a superscript ''n'' (''aⁿ'', ''eⁿ'', ...). In the orthography of the First Grammatical Treatise for the Old Icelandic language, nasal vowels are indicated with a dot above the vowel grapheme: a /ɑ/ vs ȧ /ɑ̃/, ǫ /ɔ/ vs ǫ̇ /ɔ̃/, e /e/ vs. ė /ẽ/ vs ę /ɛ/ vs. ę̇ /ɛ̃/, ı /i/ vs i /ĩ/, o /o/ vs ȯ /õ/, ø /ø/ vs. ø̇ /ø̃/, u /u/ vs u̇ /ũ/, y /y/ vs ẏ /ỹ/; the

instead indicates retracted tongue root or tense vowels, cf. ǫ /ɔ/ vs o /o/ and e /e/ vs. ę /ɛ/.

Arabic scripts

Indo-Aryan

Nasalization in Arabic-based scripts of languages such as

Urdu Urdu (; , , ) is an Indo-Aryan languages, Indo-Aryan language spoken chiefly in South Asia. It is the Languages of Pakistan, national language and ''lingua franca'' of Pakistan. In India, it is an Eighth Schedule to the Constitution of Indi ...

, as well as Punjabi and Saraiki, commonly spoken in

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, and by extension

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, is indicated by employing the nasal vowel, a dotless form of the Arabic letter nūn () or the letter marked with the ''maghnūna'' diacritic: respectively , always occurring word finally, or in the medial form, called " nūn ghunna". In Sindhi, nasalization is represented with the standard nun letter.

Classical Arabic

Nasalized vowels occur in Classical Arabic but not in contemporary speech or

Modern Standard Arabic Modern Standard Arabic (MSA) or Modern Written Arabic (MWA) is the variety of Standard language, standardized, Literary language, literary Arabic that developed in the Arab world in the late 19th and early 20th centuries, and in some usages al ...

. There is no orthographic way to denote the nasalization, but it is systematically taught as part of the essential rules of '' tajwid'', used to read the Qur'an. Nasalization occurs in recitation, usually when a final nūn is followed by a yāʾ ().

Indic scripts

The Brahmic scripts used for most Indic languages mark nasalization with the anusvāra (◌ं), homophonically used for homorganic nasalization in a consonant cluster following the vowel) or the anunāsika (◌ँ) diacritic (and its regional variants).

Languages

The following languages use phonemic nasal vowels: