In the International Phonetic Alphabet nasalization is indicated by printing a tilde above the symbol for the sound to be nasalized: [ã] is the nasalized equivalent of [a], and [ṽ] is the nasalized equivalent of [v]. An older IPA subscript diacritic [ą], called an ogonek, is still seen, especially when the vowel bears tone marks that would interfere with the superscript tilde. For example, are more legible in most fonts than .
There are occasional cases where vowels show contrasting degrees of nasality.
Nasalized versions of other consonant sounds also exist, though they are much rarer than either nasal stops or nasal vowels. Some of the South Arabic languages have phonemic nasalized fricatives, such as [z̃], which sounds something like a simultaneous [n] and [z]. The sound written r in Mandarin has an odd history; for example, it has been borrowed into Japanese as both [z] and [n]. It seems likely that it was once a nasalized fricative, perhaps a palatal [ʝ̃]. In the Hupa velar nasal /ŋ/, the tongue often does not make full contact, resulting in a nasalized approximant, [ɰ̃]. This is cognate with a nasalized [ȷ̃] in other Athabaskan languages. In Umbundu, phonemic /ṽ/ contrasts with (allophonically) nasalized [w̃], and so is likely to be a true fricative rather than an approximant.
Besides nasalized oral fricatives, there are true nasal fricatives, called nareal fricatives, sometimes produced by people with speech defects. That is, the turbulence in the airflow characteristic of fricatives is produced not in the mouth but in the nasal passages. A tilde plus trema diacritic is used for this in the Extensions to the IPA: [n͋] is an alveolar nareal fricative, with no airflow out of the mouth, while [v͋] is an oral fricative (a [v]) with simultaneous nareal frication. No known natural language makes use of nareal consonants.
K. Alexander Adelaar. 2005. Salako or Badamea, sketch grammar; texts and lexicon of a Kanayatn dialect in West Borneo.(Book review)
Dec 01, 2007; K. Alexander Adelaar. 2005. Salako or Badamea, sketch grammar; texts and lexicon of a Kanayatn dialect in West Borneo....