Speech frustration

In other news, I have a box collecting of the 'small and cheap' toys for Freecycle, and have one new addition to the toy collection - actually one more collection that's been added. Kittyboy has four little baby dolls, complete with high chair, rocking horse, and sleeping basket. And he is the happiest child around! They're his babies, and he feeds them, rocks them, and makes them go night-night. Thank you, Lisa from Freecycle! They are WELL loved!
To be candid, I am feeling the same as I did last year, when strangers were guessing Kittyboy to be half his age based on his gross motor skills and lack of babbling, except this year it's me looking at other two year olds who SAY WORDS, and in particular a six month old baby at church who babbles about like he does. Six months old, but she opens her mouth more than my son, and so when she babbles, she sounds really advanced to me. Well, I could say Kittyboy has improved by two months over when he was evaluated at 18 months to have the vocal skills of a four month old. So he's up to the six month level. That's after weekly speech therapy since September. And I am once more suspecting auditory processing as a problem. You ask him "what does a cow say?" and he signs Cow, as if what he understands is "say cow", and so he obliges. We can get a moo on rare occasion, but very rarely, more often he doesn't seem to know what we're asking. It took me forever to figure out that when he goes "Nggg!" in the car, he's actually pointing at something and, apparently, is asking about it or telling us about it. It's NOT a whine because he wants to be out of the car, or because we stopped at a light. But that's how we've treated it for months, with him escalating louder and louder before dropping the subject. How many chances to tell him about his world did we completely miss because we didn't know what he was trying to communicate, and how frustrating must it have been for him wanting to know about that big machine at the construction site we were passing, or pointing out birds, and being told to be quiet instead? He CAN talk, he CAN make noise and CAN open his mouth, but he doesn't. If it's because he isn't hearing US clearly, including not putting words in the right order, that would most certainly make it very difficult to learn how to talk. VERY difficult. But you can't test processing until he's five, six, seven years old. Speech therapy is the only therapy I see being referred to the school district in 11 months.