Common o
In North American English, the short o sound is more common.
model stop modification
[maw/d’l] [staw/p] [maw/dih/fih/kae/shun]
The letters ‘a’, ‘aw’, ‘au’, and ‘ou’ can also produce this sound.
all law caught
[aw/l] [l/aw] [kaw/t]
thought
[thaw/t]