Buzzing noise from hood while on boost?
 

Hello fellow subie owners! I have recently purchased '06 STi, and for about a month now I have been hearing a faint buzzing noise coming from the turbine area i assume? it is when i am at 50 to 60+ mph on sixth gear, when i tap on the accelerator the buzzing noise happens. or not even tapping but when i am on sixth gear just on accelerator, the buzzing continues. I wonder if there is something wrong with my turbo? or is it the loose heat shield? I am getting sorta worried, and wondering if i should take it to the shop. any ideas? I understand that sti is a very rough car but this definitely seems like a problem

Is it more like a rattling like buzz, or a whine coming from the turbine? (that sounds like the right speed in either 5th or 6th gear that I hear the turbo drone with a little bit of a whine)

Ohh and this occurs with me, not while on boost, just crusing

it's more like a buzzing, followed by the induction noise