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This paper investigates snowmobile noise, more specifically the system composed of the track, the suspension and the tunnel. Two series of tests were made to understand the snowmobile track noise. The first used the Plackett and Burman design of experiment in order to identify the most important factors in the sources of vibration. In the second, isolated tests were carried out to evaluate the importance of the sound radiation and dynamics of the track and to understand the role of the snowmobile tunnel in the acoustic response of the system. The first part shows that the most important excitation source is the passage of the studs of the track between  the guide wheels and the ground. This excitation propagates in the suspension on which the tunnel of the snowmobile is attached. The second part shows that the sound radiation and the dynamics of the track are not important issues in the studied system. Depending on the track speed, the system has two preferred ways to generate noise: airborne noise from the suspension itself and structural sound radiation from the tunnel.