my baby has turned 6 months recently. he's active, plays well, coos and babbles. also smiles in response to us n laughs wen v play wit his tummy. looks around sounds being made. looks at us wen v speak. bt he doesn't respond to his name all the time. he responds sometimes by looking at us n smiles. bt it's not consistent as of now. in between when he plays he won't look at us. his complete concentration wil b on play. is this normal? or smthng to worry? at wat age they respond to their name consistently?