Ay mama, hindi ka nag-iisa sa worry na yan, a few of us actually went through the same thing with our toddlers! Honestly, 1 year 7 months is still within the range where some kids are just quiet observers, but kasi every baby is different, I'd really suggest bringing it up with your pedia just to get their take and maybe have them check if there's anything going on sa hearing or development. In the meantime, talk to him a lot, narrate everything you're doing, sing songs, read books together, kasi that exposure talaga helps, at kung may underlying concern, the doctor can guide you better on next steps like speech therapy kung kailangan.