crying grunting and general infant noise making

At 2 months, DS just started making other than crying noises, so I'm not sure whats distress and what is just baby talk. His expression is hard to read, he usually just babbles with a straight face.
He doesn't make a face when grunting, but grunting used to always lead to crying. Well now, he adds some girgling sounds to it and its different. But without any expression I can't tell whats going on.

So today, I just let him lay in his crib and grunt, he cried out, I came rubbed his belly he calmed down. He grunted some more and fell asleep in 2 minutes. I didn't pick him up.

He was always a grunter, and the grunts always used to lead to crying and I always used to pick him up and comfort him. What do you think, would you let him grunt his way to sleep? I also just got some new toys that he loves to stare at and listen to, maybe its just numbing the cries?

I'm so confused. I don't want to do CIO with a 2 month old, but is he really in distress and need me to pick him up?

Re: crying grunting and general infant noise making

Unless he is crying I would let him be. Maybe its his way of putting himself to sleep. My DD makes a ton of noises at 3 months..some sound like whining/distress when she is tired and wants to go to sleep!