In Phonetic, the nasalisation is the production of a sound whereas the Velum is lowered, so that air escapes by the nose during the production of the sound by the mouth. All occurs like if a sound N was produced simultaneously with its oral examination.

In the International Phonetic Alphabet, the nasalisation is indicated by the presence of a Tilde above the symbol of the sound to nasaliser: is the equivalent nasalized of , and is that of .

The sounds most usually nasalized are the nasal vowels which one finds in French, Polish, and in the " twang" texan. In some cases, one can meet vowels with several degrees of nasality. (See.)

There exist also nasalized consonants which contrast with the purely oral consonants. Some of the southernmost Arab Langues have fricative consonants nasalized, such as , whose sound resembles the simultaneous emission of N and Z . The sound noted R in Mandarin has a singular history; for example, the Japanese borrowed it at the same time like Z and N . It probably was formerly fricative nasalized, perhaps a palatal . In the nasal Consonant velar hupa //, it is frequent that the language is not completely in contact with the palate, which involves the emission of a spirante nasalized . This phenomenon is connected with the nasalized consonant others Languages athapascanes. In Umbundu, it phonemic contrast with the Allophone nasalized , and it is probably about true fricative rather than of a spirante.

The nasal consonants are not nasalized , because it is not a question of an articulation added to its oral examination corresponding, but of a mode of articulation per blocking of the flow of air on the level of the mouth, whereas its passage by the nose is free. One thus speaks also about occlusive nasal .

Apart from fricative oral nasalized, there exists true fricative nasal, named fricative naréales , which is sometimes emitted by people having defects of phonation. For this type of consonants, the turbulence of the flow of air which characterizes the fricative ones is produced not in the mouth but in the nasal cavities. The wide International Phonetic Alphabet the note by two diacritic compounds, a Tilde and a Dieresis: is fricative a naréale alveolar, without flow of oral air, whereas is fricative oral (one) with simultaneous frication naréale.

See too

• nasal Consonant
• nasal Vowel
• Denasalization