Originally Posted by KuroShiro
I'm pretty sure that KQ6, in its original form, did not offer text + speech at the same time, nor did KQ5. This was the case with most Sierra games at the time unfortunately. The ScummVM team did, however, add the feature to KQ6 and SQ4 -- maybe that's what you're thinking of?
Space Quest IV actually intended
to allow this ability--there were graphics in the menu for having "Both" speech and text selected. Until ScummVM came along, though, the only way to activate it in the final game was through a bug ("unanticipated feature"?) in Hz. So Good. Go figure.