A noise attenuation device for a vehicle exhaust system is provided. The device includes an exhaust pipe having a passageway for receiving exhaust gas pulses from an engine. The device further includes a plurality of vanes extending from an inner surface of the passageway and spaced apart from one another. The vanes are configured to reduce turbulence in the exhaust gas pulses flowing past the vanes to reduce noise at a downstream outlet of the exhaust pipe.