초록 ▼

An apparatus for reducing noise characterized by a number of input microphones arranged near an undesired noise source, a signal processor coupled to the input microphones and operative to develop a number of output signals from the input signals, and a number of speakers coupled to the output signa

An apparatus for reducing noise characterized by a number of input microphones arranged near an undesired noise source, a signal processor coupled to the input microphones and operative to develop a number of output signals from the input signals, and a number of speakers coupled to the output signals of the signal processor to produce anti-noise within a designated quiet zone. Each of the speakers derives a portion of its signal from each of the input microphones so that each output transducer has the maximum amount of information concerning the noise to be canceled. The method of the invention is characterized by the steps of detecting compression waves at a number of detection locations within a medium, and developing a number of complementary signals utilizing all of the detected compression wave information.

대표청구항 ▼

An apparatus for reducing undesired compression waves in a quiet zone of a medium comprising: a plurality of input transducers positioned externally to a quiet zone of a medium which are sensitive to undesired compression waves before they enter said quite zone, said plurality of input transducers b

An apparatus for reducing undesired compression waves in a quiet zone of a medium comprising: a plurality of input transducers positioned externally to a quiet zone of a medium which are sensitive to undesired compression waves before they enter said quite zone, said plurality of input transducers being operative to produce a plurality of input signals in response thereto; a signal processor responsive to said plurality of input signals and operating in an open-loop fashion with a predetermined transfer function that is unaffected by an input from a transducer within said quiet zone to produce at least one output signal which is derived at least in part by independently processing with said predetermined transfer function more than one of said plurality of input signals; and an output transducer responsive to said output signal and operative to produce complementary compression waves in said medium which combine with said undesired compression waves in said quiet zone. An apparatus as recited in claim 1 wherein said signal processor further includes a feedback reducer to reduce feedback between said output transducers and said input transducers.