The invention concerns an internal combustion engine exhaust line comprising an active noise reduction system with variable choke device, continuously regulated based on the instantaneous discharge rate pulses of exhaust gases exiting from the internal combustion engine, including an expansion chamber for closing phases of the variable choke device arranged upstream of said active noise reduction system and a cavity dispersing medium and high frequencies arranged downstream of the active noise reduction system. The expansion chamber for the closing phases of the variable choke device is integrated in a first depolluting system arranged upstream of said active noise reduction system.