More than likely is the moose. Open the air filter housing up and see if it gets louder.
It would probably be a good idea at that mileage to pull the intake manifolds and clean the IMRC butterflies, plenum passages, and EGR passages. Also clean the throttle body and either clean or get a new IAC (idle air control).
The IAC is responsible for the noise, but crud buildup contributes to it and hurts performance.
