Roundout,
Can't tell you about taking my kids up, since that's ooooh, about 20 years off
, but I can tell you I was taken up very early (about 2 weeks old) and didn't have ear defenders or anything special - mom held me on her lap, dad flew, and it's entered in the aircraft log as 2.5 passengers in a 150
No ill-effects either, if you don't count the truely awful sense of humour