Scream a not so little scream

ARGGGGGGGGGGGG!!!!!   I've had it and can't take it anymore.  For those of you who don't know it already Jaimin is a screamer.  Not any kind of scream but a high pitch ear piercing scream.  The kind that literally hurts your ears.  Oh c'mon you say, it can't be that bad! Its bad.  He screams for no reason at all, when he wants down, up, more food, when he see's someone, when he is in the carseat, at the soccer field, in a store and the list goes on and on. We went to a Samohi baseball game the other day and had to leave because his screaming was so loud that it was distracting the players. It's constant from the time that he wakes up, to the moment he falls asleep at night.  We are constantly trying to entertain him to distract him from screaming.  We went from blaming the parrots at Adam's moms house to a possible hearing problem to maybe he is autistic.  The parrots maybe a small factor.  He definitely doesn't have a hearing problem.  And from the research I have done on autism, he is way to social and doesn't have any of the other signs.
We were in Target the other day and I heard a child screaming. I got such joy to know there was another screamer.  When I looked up to see how old the child was I saw a boy to was mentally disabled.  He had a reason to be screaming.  Something was wrong with him.  Jaimin doesn't have anything physical going on with him.  Not that I would ever wish for that, but a least if you could see that something was wrong we wouldn't get the reaction we get.  People look at us like we are horrible parents.  Like we don't know how to control our child.  Like we have a child that has behavior issues or a problem child. I have tried. We are great parents.  Talking to him about it doesn't work, ignoring him doesn't work, turning our backs to him doesn't work, screaming back at him doesn't work, blowing on his face doesn't work, covering his mouth doesn't work.  Sometimes I can't take it anymore and just want to pick him up, shake him and yell "stop it , just stop it".  But I am sure that won't work either, nor is it right.
A good friend of mine asked if we sign with him? Oh my gosh, why didn't I think of this?  We signed with Jordan when she was a baby and it was great.  So off to the computer I went to learn again the most common words in our day that we use.  He picked it up so fast!  It was great!  This is going to work!  He is now signing and still screaming.
I don't know what I would do without Adam.  He is a great dad.  I wish I could be half the mom he is dad.  He handles Jaimin and his screaming so well.  We are challenged everyday with this issue and I am at my breaking point.  I hate to be wishing away the days but I can't wait until he stops screaming or at least we find out why he is screaming.