Abstract: A following vehicle detection and alarm device comprises a tail camera for shooting an area behind a vehicle of interest at a predetermined frame rate, a frame quantity count unit for counting the number of frames after a following vehicle is shot in a shooting range of the tail camera until the following vehicle reaches a first position behind the vehicle of interest, an alarm instruction output unit for outputting an alarm instruction of notifying the driver of the vehicle of interest that the other vehicle is approaching at a timing set based on the number of frames counted by the frame quantity count unit, and an alarm processing unit for performing a predetermined alarm operation on the driver when the alarm instruction is output by the alarm instruction output unit.

Abstract: A following vehicle detection and alarm device comprises a tail camera for shooting an area behind a vehicle of interest at a predetermined frame rate, a frame quantity count unit for counting the number of frames after a following vehicle is shot in a shooting range of the tail camera until the following vehicle reaches a first position behind the vehicle of interest, an alarm instruction output unit for outputting an alarm instruction of notifying the driver of the vehicle of interest that the other vehicle is approaching at a timing set based on the number of frames counted by the frame quantity count unit, and an alarm processing unit for performing a predetermined alarm operation on the driver when the alarm instruction is output by the alarm instruction output unit.

Abstract: A microcomputer 12 selectively generates signals corresponding to a cancel sound and a pseudo-engine sound respectively based on a rotation number of an engine and causes a switch 23 of a subsequence attenuator ATT 16 to be in an ON condition for attenuating the signal corresponding to the cancel sound if it is generated and causes the switch 23 to be in an OFF condition for passing the signal corresponding to the pseudo-engine sound through it if it is generated.

Abstract: A noise-canceling method for simultaneously canceling a plurality of harmonic components of the engine rotational speed contained in engine noise. Reference signals are generated in correspondence with a plurality of harmonic components, and an adaptive signal processing is executed by using each reference signal, a composite-sound signal of the engine sound and a composite noise-canceling sound at a noise-canceling point, thereby generating a noise-canceling signal. The noise-canceling signal is input to a speaker. The reference signal corresponding to a harmonic component of a low level is multiplied by a constant K before it is input to the speaker so as to approximately equalize the levels of all the harmonic components at the noise-canceling point.