There is a fault with the sound on this one. It sounds as though cawod has been combined with some other word which begins with g-.
Nothing we can do about it, sorry.
I had 'get a shower' marked wrong in 'cyn cael cawod', but before I have one I sometimes say that I must get one. Also, being pedantic, if shopping for bathroom equipment, saying, "Before getting a shower we must check the fittings" would be a valid statement!
The usual pronunciation is as outlined in the Welsh Plus videos that we recommend in the discussion on additional resources - there is a link there. If you search the web for 'welsh plus pronunciation youtube' that should find them as well.
The a and o in cawod are both pronounced as you would usually expect. Of course, there are several regional variations, but ignore those unless you live in Wales.
There are occasional glitches in Duo's computer-generated pronunciation, too, but we have no control over that.