Need expert help. Engine Noise. (Audio clip attached)

[harryrcb]

Originally Posted by heiwaz

Hello, I started the engine for a few seconds without the belt, the noise doesn't disappear.

If it's not your front pulley's it could be a number of other things. Some may sound odd to you but I have experienced all these except one.
Have you noticed any change in power?
Have you replaced your air filter lately? if it's clogged really bad then it could be trying to suck in air throught the intake somewhere else(where it shouldn't)
If not it could be too much crankcase pressure blowing it out the vent tube
Could be the dreaded IMS bearing has gone bad
Keep looking