A lubricating system for an internal combustion engine includes a recovery pump by which a lubricating oil dropping to and dwelling in a bottom portion of a crankcase after lubricating individual portions of the internal combustion engine is sucked through a pump suction port opened in the bottom portion of the crankcase and is fed to a lubricating oil tank. A sound generating apparatus 10 includes a coordinate input device 12 for inputting coordinate data, a main control device 14, an acoustic device 16, and a display device 18. Top and bottom surfaces of the ring portion are adapted to sealingly engage the drain rim substrate.