Choral Lyric Writing

I'm currently working on a choral SATB piece, and I would like to know some of the theory behind different vowels and consonants. Like which ones resonate better, which are easier to tune, what's awkward to work with. I have some really basic ideas, based on a little reading and my involvment in choir, but I don't really know how to apply it yet. So any info on that stuff would be awesome, thanks!

In that song previously mentioned, I am thinking of mixing vowels. Like having the sopranos and tenors on an "oo" sound while the altos and bases are on the "aa" sound. I cannot imitate this in finale, and it seems the tendency for choir members is to mix the vowels together when they hear the mesh. Perhaps after they get used to the song they will stop, but what do people here think of mixing vowels? In my head it sounds cool, but I'm not sure it will end up the way I hear it in my head.

Also, I have the word "deception" in my piece. If I wanted it to be pronounced more like "day-cep-tion" instead of "dee-cep-tion" where should I notate that? Should I put it in the composer's notes before the piece? Or is there another place I should place that difference?

Thanks for all the help.

I would put an IPA translation in your composers notes. If a choir is meant to spend some time with your piece, some singers might go through your lyrics and notate them with their own phonetics or IPA.

In my 3 years studying solo voice, the one thing I learned for sure is that every singer has their own resonant strengths and weaknesses. Generally speaking, the "aah" for males and the "ooh" for females are the vowels that have the most strength in the upper parts of their registers (respectively) (although this isn't always true) and because certain vowels have different strengths or weaknesses in different registers, it's not uncommon for a trained singer to compensate by shifting the vowels slightly to maintain their volume.

Unless there's a special reason you want to adjust the vowel pronounciation (linguistic or dialectal reasons or poetic), I would put more trust into the hands of the performers to make sure that they perform your piece as strongly as they can.