My 8 month old makes a coughing/choaking sound but smiles and laughs. is he just playing?

Rubbery airways: Infants have rather rubbery airways that will not become stiff like an adults until 8-10y. The result is a musical quality to many of their coughs or giggles that can mimic a seal barking or produce random squeaks and the like.This is all based in the vibrations within the walls of the airways as they move air in or out. A laughing kid who is happily getting your attention is a good sign it is ok.