Depends on the type of map.... RPG, Bound, etc...
Bound, to me, is completely pointless to have voices.
In RPG's, voices would have a nice touch.
But WHATEVER map it is, DON'T DO HOME MADE VOICE OVERS.
About 95% of all home-made voice overs sounds like TRASH.
Not saying that yours will, if you put a crap load of time on perfecting it, I'm sure you can do some decent home-made voices.
However, your best bet is to steal from other games (giving credit to those games in your map).
There's a billion games out there.
thanx! and its a campaign map.
Voices in campaignes are a good idea. You are planning to record voices with a microphone right? The only thing I don't like about it is that is can get static and sound bad.
no matter what everymap should have a kick ass thing. starforge, and music, and transmissions. anything that would be cool should be in a map.
voices in maps?
yes! sure

in a campaign this is good!!!!!
put the damn voices, friend!!!!

It really depends... for campiagn's voices should be used. Gives it that bit more of an edge.
Other wise other maps for, battle.net I say a Big No it only increases file size...
If you can get a voice actor or try yourself.
All im syaing it go for voices someway or another.
campaign... then for SURE!!!!!
ok i see mostly yeses for the voices but only some nos for the voices.....i might not put the voices in cause to put em in SEN it takes like DAYS! to load the maps on the site cause their sooo big and cause i have a slow computer...............

ADDITION:
oh ya here are my 6 completed maps and my preview for them!
It depends.
If you have a source for good ones, or can make some decent ones by yourself/with friends, then go ahead.
If your voice sucks, and you don't know anyone with a good one, and you can't find any that happen to match your dialogue from movies, songs, and video games, then don't bother.
Well.... I saw the preview

.
It was okay, but the voices were little squeaky ones, and it was very funny. It is sometimes good to have funny voices (like if you are doing a movie) but no a campeign.
I was cracking up the whole time (more or less.) You should make a move map and insert those voices to make a comedy. If you are using the same voice, don't put in the voices.
If you can do voices well, then do them; however, if you are like the majority of people who can't do voices well because of equipment, editing software, or/and, well, your voice, then don't. Please don't.
-EE