@bcmorr Yep, aa·si·yan pronunciation seems natural. When I first heard it mentioned from our neighbors as “ah·syan”, it took me longer to understood them. ^_^;;
I think that was why you picked-up the Philippine pronunciation, it's more natural to read it as “A-SEA-N”. Of course, not saying the other variations are wrong, it's actually cool (especially since the ASEAN itself did not provide any official pronunciation guide).