Prenasalized stop

Prenasalized consonants are phonetic sequences of a nasal and an obstruent (or occasionally a non-nasal sonorant such as [ɺ]) that behave phonologically like single consonants. The primary reason for considering these to be single consonants, rather than clusters as in English finger or member, lies in their behavior; however, there may also be phonetic correlates which distinguish prenasalized consonants from clusters. Because of the additional difficulty in both articulation and timing, prenasalized fricatives and sonorants are not as common as prenasalized stops or affricates, and the presence of the former implies the latter.

In most languages, when a prenasalized consonant is described as "voiceless", it is only the oral portion that is voiceless, while the nasal portion is modally voiced. Thus a language may have "voiced" [ᵐb ⁿd ᵑɡ] and "voiceless" [ᵐp ⁿt ᵑk]. However, in some Southern Min (incl. Taiwanese) dialects, voiced stops are preceded by voiceless prenasalization: [ᵐ̥b ⁿ̥d ⁿ̥ɺ ᵑ̊ɡ].

Prenasalized stops may be distinguished from post-stopped nasals (orally released nasals), such as the /mᵇ nᵈ ɲᶡ ŋᶢ/ of Acehnese and similar sounds (including voiceless /mᵖ/ etc.) in many dialects of Chinese. (Though at least in the Chinese case, in some dialects the nasalization continues in diminished degree through to the vowel, indicating that the consonant is partially denasalized rather than actually having an oral release.) No language is known to contrast the two types of consonant, which are distinguished primarily by a difference in timing (brief nasal followed by longer stop vs longer nasal followed by brief stop), nor are any expected to.

The Bantu languages are famous for their prenasalized stops (the "nt" in "Bantu" is an example), but similar sounds occur across Africa and around the world. Ghana's politician Kwame Nkrumah had a prenasalized stop in his name, as does the capital of Chad, N'Djamena (African prenasalized stops are often written with apostrophes in Latin script transcription although this may sometimes indicate syllabic nasals instead).

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