Hello. My baby is so quiet. She's 5.5 months. She plays with toys and can not make a sound for hours then she might make a few "ahh ahh" or "oooh oooh" sounds. She smiles back but not all the time. Sometimes she does the Duchenne smile. Not really giggling yet other than a few small "hehe" and we really have to work for that! Is this normal for a baby to be so quiet? She's so happy and content and meeting all other milestones otherwise. Just worried as all friends babies the same age and squealing and cooing all the time!!