OK, for the moment, anyway, problem is solv-ed, as Clusoe might say.
I am now getting speech in the BG intro through Exult! Heh...

Weirdness abounds--OK, I was looking through my drives (almost 3TB's of capacity over several partitions and ~70% filled)--when lo and behold I found another Ultima VII installation directory that evidently I had installed long ago and forgotten about--it was just sitting there. So I said what the heck and copied over the INTROSND.DAT to overwrite the one I'd been using--(which worked fine with the intro speech, remember, with my regular DOSbox version of the game(!))--and now *speech* is working through Exult, as well! Go...figure....
I think the "corrupt file" theory is actually--has to be, the right one, even though this doesn't make a lot of sense as I cannot see why the intro speech would work in vanilla U7 but not in Exult running the same files *if* the INTROSND.DAT file is corrupted--as the file ought not work at all under any conditions if that is the case--I would think!
Anyway--thank you so much for looking into it today! Ultimately I did solve it through the original suggestions made in the original thread you pointed me to that advocated overwriting a corrupt file--because I found another identical file installed to another drive that worked--even though I've never seen a corrupt file work like this--partially, that is...! Strange. I could find no observable difference in the files--capitalization, actual size, file date, and of course *source*. Except one didn't work with 1.5 Exult and the other did!
Thanks again, Dominus! (BTW, to answer your last query--I don't even have a patch directory...

) It's always better when things return to the predictable norm, isn't it?