hissing in rear of cabin

[MURDEREDTBSS]

Hey guys

I bought a 2007 yukon slt 2 months ago and it has had a noise in the rear of the cabin that sounds like a air leak? Any thoughts of what it could be?

Thanks everyone

 

[0862]

Does it have factory air ride? Mine does that same thing every once in a while but I always assumed it had to do with the air ride.