Proto-Baap-Pwao (PBP from now on) is usually reconstructed as having the following phonemes:
pː tː c: kː <p t ṣ k>
p t c k <b d s g>
b g <ḅ γ>
m n ŋ <m n ŋ>
ɸ~p̚ v <ṗ v>
w r j <w r y>

i e a o u <i e a o u>

Syllable structure was (C)V(F), where F = ɸ, ŋ, but ŋ assimilates in POA (e.g. /kaŋtoka/ <kandoka> "fish")