Voiceless nasal glottal approximant
The voiceless nasal glottal approximant is a type of consonantal sound, a nasal approximant, used in some oral languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨h̃⟩, that is, an h with a tilde.
Occurrence
The h sound is nasalized in several languages, apparently due to a connection between glottal and nasal sounds called rhinoglottophilia. Examples of languages where the only h-like sound is nasalized are Krim, Lisu, and Pirahã.
More rarely, a language will contrast oral /h/ and nasal /h̃/. Two such languages are neighboring Bantu languages of Angola and Namibia, Kwangali and Mbukushu. In these languages, vowels following /h̃/ are nasalized, though nasal vowels do not occur elsewhere. A distinction is also reported from Wolaytta, though in that case the nasal is rare. Swazi distinguishes /h, h̃, ɦ, ɦ̃/.