think about it, if you were never able to hear people around you talk, do you think you would be able to talk completely fine. i dont think so. it makes a big impact on how you talk when you cant hear. my brother, is not deaf but he has hearing problems as a baby and untill he was like 6 and even though he had sergery to fix it, he still has some problems when it comes to talking, because as he grew up he never got to really hear the words the right way. so he kinda had to re-learn how to talk. :)
It makes a difference if they were born deaf or became deaf later in life. If they are born deaf generally they can not talk because they have no idea what words are supposed to sound like when said aloud. We learn how to speak by listening to others and mimicking the sounds - they didn't have that opportunity. The ones who can speak became deaf later in life and the reason it sounds different than how we speak is because they can not hear themselves talk.
Some can talk, but most talk differently.
Their words, and voice sound different because they cannot hear themselves speak. I believe they go by the vibrations of their voice.
They can, they just don't know what sounds they're making.