V.B.
Sometimes babies will cease using one skill (verbal/babbling) when they are starting to learn another skill (is he learning to sit up on his own or some other motor skill?). My son didn't really use much in the way of verbal skills and only has 3 words right now at a year old because he walked at 9 months, so he spent a lot of time perfecting that skill and not much effort on the verbal stuff. His pedi said that is normal, so I wouldn't worry. He is probably just moving on to something else for the time being. Once my son got really good on his feet (he's running now), he started making sounds again. He was pretty stealth before that because he would walk around, but you wouldn't hear a peep out of him! :-)