these are the sounds found in most native Twi dialects:
there are also sounds not on the chart

Other sounds:

a labio-velar central approximant [w]
voiceless stops are aspirated
palatal fricative is labialized
palatal affricates have labialized counterparts
close front, close back vowels and [a] have nasalized counterparts
long nasalized close-mid and open-mid rounded vowels

(from: Maddieson, I. 1984. Patterns of Sounds. Cambridge: Cambridge University Press.)