In the past few days he has been making this little shrieking sound instead of his usual cooing and babbling.
Everything else has been normal. Breastfeeding, his diapers, he still laughs and smiles when I play with him. He is also pretty much never fussy and rarely cries, which is the same.
So really I have no clue what this noise is.
It sounds horrible but whenever he does it I think to myself that it sounds like a stress noise, but I'm not sure what he could be stressed about.

Does anyone have any ideas about this?