(Brief background. Our son Andrew was born extremely prematurely and tiny - 1lb 6oz. He has hearing loss and development delay. He's now 21m actual, 18m corrected, and about 15m in behaviour.)
Andrew's had hearing aids since December - and we've noticed no change in his speech. He makes no real consonant sounds at all. He refuses to co-operate in audiology tests. We feel he has some level of hearing, and that the aids make little difference; the audiologists disagree and are asking us to persevere. He is going in for MRI & CT scans next month to look at the formation of his inner ears. They have likened his hearing to a faulty fluorescent light - it flickers on and off, so sometimes he hears and other times he doesn't.
We can get Andrew to wear his aids for around 6-8 hours a day, depending on how awkward he's feeling. We use double-sided tape to anchor the aids behind his ears; and we then tie on a thin cloth bonnet to cover them completely. Although this muffles the sound slightly, it does mean that he keeps the aids on for much much longer; the audiologist was most apologetic that the standard issue "bonnet" with mesh sides simply isn't made in a small enough size for him.
Andrew has now come to accept the aids being placed in; we generally distract him by switching on the ceiling fan (so he watches) or OH dangling a toy above his face. He will pull them out though, his fingers are just the right size to get in the loop of the tube between mould & aid. Hence the bonnet!
Ask your audiologist about a referral to the speech therapy team, s/he will advise you whether it's too early or not. We were advised that Andrew wouldn't be referred until at least after his second birthday.