Voicing in Qaqet: Prenasalization and language contact

Qaqet is a non-Austronesian Baining language of Papua New Guinea, with a very small phoneme inventory of 16 consonants and four vowels, including the voiced stops /b d ɡ/. These stops are often phonetically realized as prenasalized [mb nd ŋɡ], and this feature is assumed to be a result of language contact with surrounding Oceanic languages. Our data consist of isolated word recordings from six female speakers of the language. Using a range of acoustic measures, we compare these phonetically prenasalized stops with non-prenasalized tokens of the same /b d ɡ/ phonemes, and with the nasal phonemes proper /m n ŋ/, as well as with the unaspirated voiceless stops /p t k/. In general we find that the nasal murmur of the phonetically prenasalized stop does not fully resemble the nasal murmur of the nasal consonant proper – instead the phonetically prenasalized stop patterns between the nasal consonant and the phonetically non-prenasalized voiced stop. However, there is a clear place effect, whereby the phonetically prenasalized velar stop patterns more closely with the nasal consonants, and the phonetically prenasalized bilabial stop patterns more closely with the phonetically non-prenasalized voiced stops – with phonetically prenasalized alveolar in between the bilabial and the velar. This is particularly reflected in the distribution of energy below and above about 350 Hz. However, measures of voicing strength suggest that voicing for the velar is weaker across all manners of articulation, in line with the general difficulty of maintaining voicing at this place of articulation. We conclude that prenasalization of the voiced stops largely serves to maintain voicing for the velar place of articulation; and that if the feature of prenasalization was borrowed from neighbouring languages, it was to maintain voicing for long closure durations in a true voicing language, particularly at places of articulation where maintaining voicing is difficult.