So apparently Lady Gaga smokes... a lot, which is news to me, but may not be news to the rest of yous. :P

I feel like a total kiss-ass douchebag fan, but wwwwwhat the funk?!
I'm so upset. I mean, I'm all for celeb laissez-faire (because they're people too, believe it or not. ), but in the music business, smoking, especially if you sing, is PURE EVILLLLLL!

Her voice has definitely changed over the years... and not necessarily in a good way. She still has major pipes, but there is a difference. Someone's voice does not change that drastically within the period of 1-2 years.
Take a listen:
--This was Ms. Gaga when she was still relatively new, performing "Poker Face" acoustic live:
http://www.youtube.com/watch?v=1nIvymJdjA0
Her

--This is Lady Gaga again, performing the same song on Ellen, a little later:
http://www.youtube.com/watch?v=7CUYvWTd6oA
Notice a deeper tone in her voice... there's a bit of hoarseness there.

--Lady Gaga spring 2010
http://www.youtube.com/watch?v=oZ7N3ygYFZ0
Almost like a bounceback, but her voice sounds a lot airier... if that makes any sense. And, as I said before, she still commands great vocal prowess, but her voice just sounds weaker and a little watered down.

Her speaking voice has also changed dramatically. She used to have a very cute, quiet voice, and now her voice is louder, but hoarse (I don't know how many times I'm gonna use that word, just bear with me). Go watch her BBC interview on youtube (her explaining Poker Face) and then watch her late 2009 interview with Ellen Degeneres.

If you compare her earlier work (Vanity, Wonderful, Just Dance, etc) with her newer work (pretty much all of the Fame Monster) I think there is a difference in the sound...
She had a very Gwen Stefani-like upper register (I can't find any other way to describe it), and now she has a lighter, airier high vocal range.

I might just be spitting out a huge pile of obsessive nonsense here.. just sharing my opinion.
If there's any other point I can make, I'll say that amidst my impregnable love for everything Gaga, I miss how she used to sound...
She's overworked, constantly on tour, and not taking care of her vocal chords. Lady Gaga needs a healthy dose of R&R.

Smoking is very bad if you're a singer (it's about the same as, I don't know, drinking milk right before performance, or eating chocolate before performance). I think her voice has changed, but you're right, she probably is stressed out, I mean, she's almost always on tour. Singing deep songs if you don't have a very deep voice can be bad. Then again, same thing for singing very high pitch songs.

Well in the fame monster she has the song So Happy I could die which is her fear of addition aka cigs, pot, weed, beer, ect. She used to drink alot and she used to smoke and smoked pot. But she stopped now She only smokes at her concerts for affect so she is a good healthy gaga ^_^ She can change her voice alot if u watch her live vids and of course remember its not gonna sound as good as it does on the CD cause of the overplay revamps and they can correct any mistakes on the song in the studio. So dont worry gaga dose not smoke ^_^ She acctually speaks out against it. ^=^ She has a wonderful voice on the CD's and at live preformances ^=^