These are weird symptoms. I have never read of anything exactly like this.
These injectors are electro piezo and usually very quiet, in fact because of their design, I don't see how they could be noisy compared to the older type.
Any smoke or bad smell from the exhaust?
If you could test with VCDS Engine measuring blocks 14-17 on the engine it will show smooth running mg/S for each cylinder and if any is over +/-2.99 (typical good condition is +/-0.5) then injector is not operating correctly. I wouldn't use it until you can have it looked at for fear of causing damage.
Good luck
