Poodicat, I used to do a similar job to yours, with some equally 'eccentric' clients. I remember once taking one chap to the local market. Bless him, he was blind and almost totally deaf and, with no language, 'vocalising', as you call it, was his only way of expressing anything at all. With the breeze on his skin and all the shouting going on, he let rip with a sound reminiscent of a Mohican war cry. One stall-holder began to mimic him, and not kindly either. As we walked away, a woman came up us and said "people like him should never be allowed out in public." I was about to round on her and give her a piece of my mind when she continued, "yes, and I'm going to report him to the market inspector too - he'll never trade here again if I have anything to do with it." She meant, of course, the trader. She went on to tell us how much she appreciates what carers of these guys do and how it was a crying shame that there were still people in the world who couldn't accept their right to be out in public as much as the next man.
Actually, we never saw that trader again, so I think she must have reported him.
As for me, well, if I look at you and your guys when you're out, please know that it's not out of rudeness. I just appreciate what you're doing and I'll be the first to offer you a hand if anyone has a go at you. So keep going, hon. You're all welcome in our library anytime.