Breathe in…
“Hwrrrr!”
Breathe in…
-groan-
Breathe in…
“Mmm…”
Breathe in…
“Prprprprrrr”
Breathe in…
“Ooh, parrr….”
Breathe in…
“Psshheeeww”
Breathe in…
“Shhhhhhh”
Breathe in…
-massive vocal yawn
Breathe in…
-pig snort noises
Breathe in…
-blows raspberries
Breathe in… !! Cough !!   “Hwaraaaagh!!!!”  

Pause…  

Breathe in… “MmmmMMMmmm”  

And repeat…  

These are the noises coming out of the mouth of the bouncy castle sized man sat across the aisle from me on the train.  

I could be wrong; it could be his blowhole.