Maybe he can't hear well.
Either he feels you are not listening to him or he has a hearing issue or impediment.
If you have taken him to Dr's and they say he is alright then he is fine. He is just being a typical kid. <br />
Both of my kids are still loud at 6 and 8 and they don't quiet down unless they are reminded somehow. When they were younger I used to make them turn their own volume down by twisting their own ear gently like you would turn a volume knob down on a stereo. This worked for a while. <br />
Now to remind them I will walk up to them and gently and repeatedly tap them on the hand or leg until I have their attention. This would be about as fast as you trying to keep the beat to a very fast song on the radio. I will urge that both of these things are GENTLE, lest someone think I am beating or abusing my kids. <br />
Occasionally we have to result to talking louder than they are to get their attention, but the repeated promptings have made some headway. Get creative in finding a solution and good luck.
Keep it simple silly<br />
Concern With Doctor about your son ear.Because when we listen loud then we also spoke loud