A noise suppression system for an electric generator having a housing including an internal combustion engine and air-cooled alternator. A fan draws ambient cooling air into the housing for cooling the alternator. The system may include an acoustically designed noise suppression shroud forming a cavity which contains a plurality of parallel flow baffles. The baffles define air flow passages there-between which receive cooling air heated by the alternator. In one system, the baffles are configured and arranged to block a straight line of sight between the entrance and exit of each passage. The baffles may each further include sound deadening materials on one or both sides in some configurations. Heated cooling air flows into the shroud and through the passages before being discharged from the housing. The shroud is operable to suppress noise produced by the cooling air discharge flow. Various shroud configurations may include additional sound proofing features.