Helmholtz Resonator

Was reading through the description of how the KIPS on the KDX works, and though I am familiar with the exhaust valves on 2 stroke snowmobiles and older Yamaha YZs, this appears to be more sophisticated. I am assuming the chamber on the left of the cylinder is the Helmholtz. I'm not quite sure of the operation, whether it functions through sound waves, or just adds volume to the exhaust pipe? Anyway if anyone there would care to enlighten me, please do.

Thanks, got the service manual today, and I have a clearer understanding of its function. Evidently the device that we have know in snowmobiles and some of the older IT Yamahas we called a boost bottle was indeed a Helmholtz resonator. Those were on the intake side of the cylinder. Switched out the stock fork springs today and got a real surprise, dampner rods were attached to the fork tube cap, this made things a little more complicated.