Aw, normal lang yan mommy, especially at 10 months, maraming babies nag-eexperiment with different sounds and movements kaya minsan umiiling, umiiwan, lahat yan part ng development nila! A few of my mum friends noticed the same thing sa kanilang babies around that age, kaya don't worry too much. That said, kung parang labored siya or kung may ibang signs na off sa inyo, mas safe na i-mention sa pedia just to be sure everything's on track. Ang bata mo ay likely exploring lang, yan ang cute part ng stage na yan!