I recently described Dmitry as non-verbal, but that’s imprecise. He certainly verbalizes a lot. He loves the sound of his own voice.
He definitely favors vowels, especially the OOOOO sound and AAAAA sounds. He can produce a deafening AH AH AH AH AH sound that rivals the screech of a lorikeet being sucked into a jet engine at cruising speed.
I don’t really call this “his own language”, because it isn’t. Language is a series of sounds meant to convey an unambiguous message, whereas Dmitry’s sounds are seemingly random, loud, unprovoked, and usually solitary (meaning he does it alone, away from his therapists or parents.) But it’s gotten more… variegated in pitch, tone, and complexity. They’re “stims”, but he’s learning from them.
The titular sound, DOOO-etc, is still his favorite sound (usually followed by copious tongue-clicking). But lately he’s been experimenting with different consonants. GOOOO is gaining popularity, along with LOOO LOOO LOOO and DOOO DOOO DOOO and DAAAA DAAAAA DAAAA and LAAAAAAW LA LA LA LAAAAAAAA and MMMMMMMMMMMMMMMMMMM.
I think it’s comparable to listening to a baby babble. He experiments with sounds, broadening the range of tricks that his tongue can do. But instead of the soft sighs and giggles a 9-month-old is known for, Dmitry is a healthy 3 year old with an impressive set of pipes. Say, the pipes of the top two octaves of the Mormon Tabernacle Choir organ.
Once in a great while he’ll say what appears to be a real word. He makes sure to keep his own counsel whenever a question is asked, and no amount of cajoling will yield an intelligible word, even when he’s in great distress. He likes to keep Mommy dangling with the occasional utterance of “night-night” or “yes.” But his comprehension and vocalization are as murky and inscrutable as anything else he does.