Originally Posted by
nbs2
"make"? you don't. you can't
Help them to be quiet, on the other hand, is doable. The easiest thing for the descent is to give them something to drink or eat - and be consistent about it. I find that fruit snacks work especially well because they are so chewy. My daughter seems to be less bothered by it, as we fly enough that I think she is starting to get the idea that the eating/drinking motion makes it feel better. She may not get the principle, but she has the solution. When she gets older, we can talk about it, but for now, cause and effect are good enough.
(bolding added)
Maybe for a toddler age two or three but not for a baby, surely? Babies don't have teeth. "Chewy" snacks would be devastating to a baby--though I trust that you didn't mean to recommend giving chewy snacks to a baby.
Maybe a bottle on descent. That's the usual recommendation. Whether it works would be variable. The point is, descent hurts a baby's ears, and naturally the baby will cry. But it's just for a few minutes.
Crying from fatigue is different. That goes on until the baby finally falls asleep. For that, playing music (music thoughtfully provided by the ear whatevers in the armrest) is very helpful. Music helps the little ones drop off to sleep.