Our DD wasn't talking at 16 months, so we self-referred to early intervention. My understanding is that while it is not "normal" to not have any words at this age, it does happen often and many children in this situation of being "late talkers" do catch up on their own. Our DD is 2 yo now, and she's talking a ton and graduated from early intervention after just a few months. She did start daycare around that time as well which may have helped. I think it's likely she would have caught up on her own, but I found the services useful, and worthwhile.
Some of the strategies we used are:
- Overarticulation (pronounce words very slowly)
- Tapping (tap your hand on baby's shoulder as you pronounce each syllable of each word
- As she started to talk, encouraging it. Like if she was playing on her ride on toy and she wanted me to push her more, wait for her to say "more" before I pushed her.
These are just some examples, and I think if you do go to early intervention they will customize the strategies to your specific needs. If you are in Maryland you can self-refer using this website (you want to "make a referral")
https://referral.mditp.org/