Audible hissing / whistling sound when pressing gas

[Sid]

My 2009 Corolla with 80k miles has this wierd hissing / whistling sound when pressing and releasing gas. I have attached audio file in which I press and release gas repeatedly. You will notice a sharp loud sound when releasing it and a bleak continuous sound when I press it again.

This has been happening for few years and has always bothered me, but not enough until now when my commutes have increased.

I read the forums and wondering if it be a vacuum leak somewhere?

Would really appreciate your help for any clues.

Thanks
Sid

 

[Muhammad Ali Khan]

No problem. This is the sound your throttle makes when engine is drawing lots of air and you close the throttle butterfly valve.

 

[DCBronco]

It's that turbo kicking in bro!

No but seriously, it's just more air being drawn into the intake. I love that sound because it really does sound like an extremely weak turbo spinning up.