Those are what I got for Little Bowie. He doesn't seem to mind them too much, which is good, because he cried the one time I started the car with him nearby when he wasn't wearing them... maybe he could hear the holed piston or something?
No, he cried because it wasn't a familiar sound. You could have an air-raid klaxon in your house, provided the kid had heard it go off from day 1 they'd just think its standard op.

Watch the rotories & F500's. Those seemed to make my boys upset more than anything else when they were little, can't say I blame them.

At 3 months my first kid slept through the GT-1 start while at the turn 3 fence.

Bring the kid. Families that race together, stay together.