I am going through this now. My nearly 2yo is booked in to see the ENT specialist this month where I think he'll have to have grommets. In the meantime the doctor has put him on a long course of antibiotics as he can't seem to shift the fluid behind his eardrums. He hardly speaks, none of his words are clear except for 'mum-eh' (Mummy) and 'Dah-de' (Daddy). My friend went through this with her then 18mth old. Her doctor likened her little boy to hearing under water. After grommets his speech improved dramatically and now, 3yrs on he's at school and you wouldn't even know he had a hearing issue.