aʊ

How is /aʊ/ usually spelled?

ow, ou

How do we produce /aʊ/?

It's a long diphthong. Move your mouth from /a/ to /ʊ/. At first your mouth is wide open, then you should round your lips a little, push them a little forward and move the back of your tongue up.

/klaʊn/

clown

/saʊθ/

south

/haʊs/

house

/maʊθ/

mouth

/kaʊ/

cow