Prenasalised consonant

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 them to be single consonants, rather than clusters as in English finger or member, lies in their behaviour; 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, and the nasal portion is modally voiced. Thus, a language may have "voiced" [ᵐb ⁿd ᶯɖ ᶮɟ ᵑɡ] and "voiceless" [ᵐp ⁿt ᶯʈ ᶮc ᵑk]. However, in some Southern Min (including 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/) in many dialects of Chinese. (At least in the Chinese case, nasalization, in some dialects, continues in a refuced degree to the vowel, indicating that the consonant is partially denasalized, rather than actually having an oral release.) No language is believed to contrast the two types of consonant, which are distinguished primarily by a difference in timing (a brief nasal followed by longer stop, as opposed to a longer nasal followed by brief stop).

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