MacBook Pro - strange noise ?

Hello,

if I turn my rMBP 15" with Mavericks on, I can hear a strange noise coming from the area around the hinge. It sounds like a "hiss" and it's pretty quiet.

It's directly after you push the start button.

I've had it on my old 2012 rmbp too so I don't know if it's a defect or not.

Could you please check if you can hear the same sound ? Thnx