Just thought I would chime in and say DS6 is most certainly a hummer. You get used to it in time. It has bothered other kids at school at times, half the time he really isn't aware of it. Usually it is when he is really into things and thinking too...but it can be lots of different times. Gum does help, but we save it for when we are out and it is expected he is quiet. He doesn't hum during watching TV and a few other times during the day. Those moments of quiet are nice. I am happy he seems to be happy though, and I have learned to zone it out at times.
