How many different sounds are there? I seem to remember there are 14!

dough - oh

plough - ow

enough - uff

hiccough - up

borough - uh

cough - off

What are the rest?

I thought (-or 7 ) there were 13; I can't go through (-oo 8 ) them all though.

Not sure hiccough - up should be in that list, Neeranam. The sound "up" at the end tends to be a regional trait to native English speakers and I've never come across the sound being taught like that.

From memory, your list is missing /u:/ (e.g. through) and / Ɔ:/ (e.g. brought, bought, thought, ought).