Ds (ADHD & likely hfa with maybe a pinch of auditory processing disorder) spoke early... with a fairly large vocabulary. But oddly (in hindsight) it was mostly words beginning with D. He then moved on to do starting with B. Now I know these letters are easy to pronounce so babies will start with them when babbling. But I've never seen a NT dc develop vocab in alphabetical order.... He did have some other random words but the bias was pretty strong.
We're seeing an audiological physician soon, obviously I can't mention every last detail in a short appt and I'm trying to work out what's a priority to focus on.