When did your baby start saying sounds like ‘ba,’ ‘ma,’ ‘ga,’ or ‘da’?

My baby is almost 8 months old and hasn’t started saying ‘ba,’ ‘ma,’ ‘ga,’ or ‘da’ yet. I’m starting to feel a little worried because I have friends whose babies are already saying ‘mama’ or ‘dada.’ My baby started to squeal at high pitch levels. Loves blows raspberries ALL DAY and says ‘ahh,’ ‘ooo,’ ‘hhh,’ and ‘mmm.’”