"Bilua is sometimes grouped with the other Central Solomons languages and beyond (Wurm 1975b) but closer inspection shows that a genealogical relation is not demonstrable (Dunn and Terrill 2012, Terrill 2011)" (Hammarström, forthcoming).
The voiced stops and affricate sounds /b d ɡ dʒ/ can occur as prenasalized allophones, when occurring intervocalically [ᵐb ⁿd ᵑɡ ⁿdʒ]. Other consonant allophones include [w tʃ] for /β dʒ/.
Woodley, Ellen Joanne (2002). Local and indigenous knowledge as an emergent property of complexity: A case study in the Solomon Islands (PhD thesis). University of Guelph. S2CID129399351.
Further reading
Terrill, A (2011). Languages in Contact: An Exploration of Stability and Change in the Solomon Islands. Oceanic Linguistics. University of Hawai'i Press.
Donohue, Mark, and Simon Musgrave (2007), "Typology and the Linguistic Macrohistory of Island Melanesia.", Oceanic Linguistics, 46 (2): 348–387, doi:10.1353/ol.2008.0011, S2CID127188288{{citation}}: CS1 maint: multiple names: authors list (link)