I suppose one's ear gets sharpened fast, out of necessity - but I recoil at imagining what the other band members have to get through meanwhile. The process for violin is the same though.
But brass being out of tune is not as hard on the ears as the squeaks from a beginner clarinet or saxophone...
Probably the most parent friendly is the flute. It's really hard to get good volume out of a flute so beginners are really quiet and inoffensive. :)
(I played trombone throughout middle and high school.)