First, let me say that if he has actually *lost* words, then my experience might not be right for you. Then again, kids are forgetful, and one day they know something, next day they don't, next day they do, etc.

Or so I've noticed.
I can't say exactly, but 22 months does sound around the right age. Where it's not absolutely awful that they aren't talking up a storm, especially given that they are boys, but it starts making people nervous.
I'm not a worrier about those things, and I don't much care for western medicine, and DS's health care provider wasn't concerned, but I know from internet experience that other doctor-types would be nervous about it. So when DS wasn't talking much (he signed a little bit, and we could always figure out what he wanted, but in terms of actual English there wasn't much) it didn't worry ME, but I knew it would worry other people.
I say now I was starting to think about wondering about if I should think about being worried, LOL.
Growing up, we were PBS kids. Only. Our road was unincorporated and without cable even once it was invented, and we only got a few channels anyway, but PBS is all we could watch for a LONG time. I figured I would be the same, but then when I got a peek at what Sesame Street had become, I did NOT like it. NOT the biggest fan of Elmo, nor do I like that Snuffleuphagus was made "real".

So I was at a loss.
One day I remembered that my friend really liked Blue's Clues, when her son was little (he's in his young teens now, I believe), and I decided to put it on. We both really REALLY liked it, and we started watching it.
And all of a sudden, boom, he had a language explosion. He was learning words every day, and things that I hadn't even heard while in the same room were getting into his head! It was astonishing and very cool.
DS has always had a late bedtime, mainly so he and DH can spend time together, so it's not that Eamon didn't hear a male voice, it's just, maybe, the way Steve talks and "interacts" is different from how Robert talks.
Probably about 6 months later I ran into a second cousin who lives around here. Our family is big and spread out and doesn't communicate, so I didn't even know she still lived here or worked at the upscale grocery store! She had gotten married and had a baby since I last saw her, and in quick girly chat she mentioned that her son was around that age and that his ped was starting to think about being concerned about it. I mentioned Blue's Clues. A few months later, I heard from her again, and the SAME thing had happened with her guy. He went from very few words to tons of words.
Now it could all just be coincidence, waiting it out, natural timing. It could. But for me I really think that BC had something to do with it. It was the way he learned, the words he learned, the way it all happened. Didn't feel like coincidence to me, but of course I'll never know.
I wish you luck with your little guy!
Do you have other kids; is he a younger? IF so, that might also be it. I'm the oldest, and I could always figure out what my brother needed. He didn't HAVE TO talk, and boy oh boy he didn't. I think he was 3 before he really started to talk, b/c all his needs were being met, either by my mom or me telling my mom, without speaking.