You can try to talk to them, but they just can't talk back until they are about twelve months, give or take a few months.
Babies communicate in ways other than speech.
Parents may not realize that a baby sometimes cries just to exercise his lungs. Especially if a lot of company is over, but not necessarily always the case, a baby may end up feeling overstimulated. Babies need time to comfort themselves. Averting the gaze is a very subtle communication signal, but with babies, they have so few ways of communicating, that they will use any ways that they can. You need to pay close attention to baby Jimmy's communication signals.