Apparently, young babies (0-3 months) share a language. Five words or noises specifically. I plead that you watch this video. It’s brilliant.
Click here for the video.
(I’m not clever enough to embed it.)
In short, nah = hungry, howh = sleepy, heh = discomfort, eair = lower gas, eh = burp.
Thanks to Sarah Giles for pointing this out.