Makes a terrible loud noise. It hurts my ears.

Could be the brush roll, remove brush roll and see if noise is still there when brush roll motor is running.

Check( 'beater bar',suction tube to canister) for accumulation of hair,carpet fiber,pet hair,etc....cut hair,etc,with scissors,clean...might also be hair stuck in belt that drives beater bar

The shark hand held vac , Makes so much noise when I use it I have to use ear plugs.

If it is not something wrapped around the beater bar (lay flat and turn over to check, remove floor plate if necessary), an object loose in one of the pathways to the dust collector, or a failing motor then I'm not at all sure.

What kind of noise?

It may have a bad clutch belt. When the belt on the clutch begins to slip it makes a terrible noise. If the noise is gone when the brush roll is off you will have to take it to a dealer.

If the ball was stuck and you sucked water into the motor it could cause it to smell like it's burning if it ruined the motor

hi.
it sounds like the bearings in the motor are worn out. the only solution is to change the motor, or the entire hoover. motors are available from ebay for about £35 and it will then need to be fitted. unfortunately these bearings do wear out eventually. once they start to make screeching noises like this, there is not much life left in them, and they will get worse rapidly.
if you decide to change the motor yourself, please feel free to ask for more details on how to do it.
hope this helps

i would start by inspection of the filter could be plugged up or even missing,try removing it and running it has noise changed ?if not it would seem like maybe your neighbor used it with out filter and vacuumed up cement or aggressive particles causing motor damage.

That is an indication that the belts are worn, stretched or broken. You simply need to replace the belt. Here is a link to the belt(s) you need and a manual you can view:

Dyson DC07 Belts and Manual

The belt that rotates the beater bar may be damaged - call the Dyson helpline for troubleshooting and for a solution to the problem.