Patent ID: 8111835

Claim:
An active noise control apparatus comprising: a control unit for generating a control signal for canceling out a noise in a passenger compartment of a vehicle; a sound output device for outputting a canceling sound for canceling out said noise based on said control signal, into said passenger compartment; and a canceling error signal detector for outputting a canceling error signal representing a canceling error sound between said noise and said canceling sound to said control unit; wherein said control unit comprises: an A/D converter for converting said canceling error signal from an analog signal into a digital signal; an echo canceller for correcting said control signal and thereby generating a digital echo canceling signal based on a corrective value corresponding to transfer characteristics between said sound output device and said canceling error signal detector; a subtractor for generating a first basic signal by subtracting said digital echo canceling signal from the digital canceling error signal; a delay filter for generating a second basic signal by delaying said first basic signal by a time corresponding to a ¼ period of a resonant frequency determined by resonant characteristics of said passenger compartment; a first filter for correcting said first basic signal thereby generating a first corrective signal; a second filter for correcting said second basic signal thereby generating a second corrective signal; an adder for generating the control signal by combining said first corrective signal and said second corrective signal; and a D/A converter for converting said control signal from a digital signal into an analog signal and outputting the analog control signal to said sound output device.