Errr... none of the above?
I pronounce it "Teh", a bit like "Terrible" if you were to stop talking after the first 2 letters.
Effectively, it becomes "Te' Forum"
Like 'eh', but with a 't' in front of it. So shorter than 'tear' (as in rip) and an more abrupt ending.
Sounding more like 'bleh', come to think of it.