| 摘要 |
PURPOSE:To reduce noise at the outside of a vehicle by driving a speaker provided in a duct in a way of sending a sound wave to cancel the noise at the outside of the vehicle based on a signal from a sound wave sensor provided to the depth of the plural ducts formed by division of air-intake and delivery covered with a shield plate. CONSTITUTION:The noise at the outside of vehicle propagated to the side of a power plant part of the vehicle is blocked by a shield plate 6 and the noise at the outside of vehicle going to be outputted through an air-intake 2 and an air delivery 17 is detected by a sound wave sensor 16 and the detection signal is processed by a controller 14. The controller 14 drives a speaker 4 to generate a sound wave (sound wave of nearly same sound pressure level and nearly opposite phase) to cancel the sound wave included in the noise at the outside of the vehicle thereby blocking the noise. Thus, the noise going to go outside from the air intake 2 and the air delivery 17 is reduced. |
