Speech delay? Sleep problems? Is it inner ear fluid?

Are they connected? I have a 2.5 year old with sever speech delay. He only says “no”. He communicates non verbally, he’s generally very happy and affectionate. He has been evaluated and has worked with early intervention, it hasn’t helped. Our new path is trying to find out if it’s maybe his hearing. He can hear, but my doctor suggested maybe it’s just that he’s not hearing well. He also has always had problems sleeping. We have never found the right concoction of nap/bedtime routines that work for him. Hes currently not napping during the day, falls asleep around 9pm, wakes up between 3-5am, stays awake for an hour or 2 and then sleeps until 10am. But if I were to give him a nap during the day, he wouldn’t fall asleep until midnight. I read sometimes inner ear fluid can affect sleep? HAS ANYONE ELSE BEEN THROUGH SOMETHING LIKE THIS?