Parameters for distributions of a hidden trajectory model including means and variances are estimated using an acoustic likelihood function for observation vectors as an objection function for optimization. The heart cam and damper unit is interposed between a main body portion and a movable portion which undergoes opening and closing action with respect to the main body portion and is constantly urged in an opening direction. At least one of the rings extends beyond an outer edge of a wafer to be planarized by the CMP belt. Then, a videoaudio signal synchronization controlling device controls the video output controlling device so that a decoded video signal whose position on a time axis is coincident with that of the decoded audio signal is outputted in synchronism with the decoded audio signal. The base has multiple downwardly projecting blade-like teeth for penetrating into the seafloor.