An air suction device is provided with an air suction system having at
least one capacity-enlarged portion, a compression pump compressing air
in synchronization with operation of an engine, a compression air control
unit, and a vibration plate which is vibration-excited by air compressed
by the compression pump and disposed in a connection passage connecting a
discharge side of the compression pump with the capacity-enlarged
portion. The compression air control unit controls the phase and
amplitude of a pressure variation of compression air discharged from the
compression pump, to provide compression air with the pressure variation
having the phase opposite to a pressure variation of suction air sucked
into the engine.