A
nasal vowel is a
vowel that is produced with a lowering of the
velum so that air escapes both through
nose as well as the
mouth. The term stands in opposition to the term "oral vowel" refers to an ordinary vowel without this nasalisation. Note that these terms can be slightly misleading as the air does not come exclusively out of the nose in nasal vowels.
In most languages, vowels that are adjacent to
nasal consonants are produced partially or fully with a lowered velum in a natural process of
assimilation and are therefore technically nasal, though few speakers would notice. This 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). However, the word "huh" is generally pronounced with a nasal vowel.
In
Portuguese and
French, by contrast, nasal vowels are phonemes distinct from oral vowels, since words exist which differ mainly in the nasal or oral quality of a vowel. For example, the words
beau "beautiful" and
bon "good" are pronounced virtually the same, except that the former is oral and the latter is nasal. (More precisely, the vowel in
bon is slightly more
open, leading many dictionaries to transcribe it as .)
Suprasegmental and transitional nasal vowels
In
Min Chinese, nasal vowels carry persistent air flow though both the
mouth and the
nose, producing an invariant and sustainable vowel quality. That is, this type of nasalization is synchronic and
suprasegmental to the voicing. In contrast, nasal vowels in French or
Portuguese are transitional, where the
velum ends up constricting the
mouth airway.
In languages which have transitional nasal vowels, it is commonly the case that there are fewer nasal vowels than oral ones. This appears to be due to a loss of distinctivity caused by the nasal articulation.
Orthography
Languages which are written in the
Latin alphabet may indicate nasal vowels by a trailing
silent n or
m, as is the case in French, Portuguese,
Bamana or
Yoruba; others use
diacritical symbols (Portuguese also employs a
tilde ~ on
ã, õ, before vowels;
Polish and
Navajo use a hook underneath the letter, called an
ogonek, as in
ą, ę). Other languages may use a superscript
n: aⁿ, eⁿ. In the
International Phonetic Alphabet, nasal vowels are denoted by a tilde over the symbol for the vowel, as in Portuguese.
Abugida scripts, which are used for most
Indian languages, use the
bindu (.) symbol and its variations to denote nasal vowels and nasal junctions between consonants.
The Nastalique script used by
Urdu denotes nasalisation by employing the Arabic letter "noon" but removing the dot. It is called a noon-ghunna or nasalized N. Nasalized vowels occur in classical
Arabic, but not in contemporary speech or standardized
Arabic. There is no orthographic way to denote the nasalization, but it is systematically taught as part of the essential rules of
tajweed employed while reading the
Quran. Nasalization usually occurs in recitation when a final N (noon) is followed by a Y (ya)
Example languages
Languages which use phonemic nasal vowels include, among others:
- Paicĩ (an unusually large number of nasal vowels)
See also
Category:Vowelscs:Nazální samohláskade:Nasalvokalfr:Voyelle nasalefy:Nasalearringit:Vocale nasalepl:Samogłoska nosowaru:Носовые гласныеsv:Nasal vokalwa:Voyale naziålezh:鼻化元音 
