I personllay am not in favor speeching to your baby with a special baby tone but i read this information in Kikipedia where you can get some ideas of words for 'babies'.
http://en.wikipedia.org/wiki/Baby_talkHere they say :
' Baby talk is more effective than regular speech in getting an infant's attention. Studies have shown that infants actually prefer to listen to this type of speech. Some researchers, including Rima Shore (1997), believe that baby talk is an important part of the emotional bonding process'
I think I have to do some more investigation for when my 2nd grandchild arrives (not planned by any of my kids right now.
My grandons is 3 1/2 yrs so definitely baby talk is not for him.