Noise reduction apparatus

A noise reducing device comprising:

• a speaker unit comprising a plurality of speakers arrayed so that the direction of sound emission therefrom faces in a predetermined direction;
• a first microphone, disposed so as to correspond to the speaker unit, and collecting the sound of a noise and outputting a first acoustic signal corresponding to the sound of the noise that has been collected;
• a second microphone, disposed in a position that is separated in the speaker array direction from the disposed position of the first microphone, and collecting the sound of a noise and outputting a second acoustic signal corresponding to the sound of the noise that has been collected;
• a third microphone, disposed in a position that is separated in the speaker array direction from the disposed position of the first microphone in the opposite direction to that of the third microphone, and collecting the sound of a noise and outputting a third acoustic signal corresponding to the sound of the noise that has been collected;
• first control signal output means that outputs, on the basis of the first acoustic signal, a first control signal for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the first microphone;
• second control signal output means that outputs, on the basis of the second acoustic signal, a plurality of second control signals for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the second microphone, the plurality of second control signals having each been delayed respectively by incremental predetermined time periods;
• third control signal output means that outputs, on the basis of the second acoustic signal, a plurality of third control signals for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the third microphone, the plurality of third control signals having each been delayed respectively by incremental predetermined time periods;
• and
• control means, controlling such that the first control signal is input simultaneously to the respective speakers, such that the second control signals are input with gradually increasing delay times from the speaker at one end of the speaker unit toward the speaker at the other end of the speaker unit, and such that the third control signals are input with gradually decreasing delay times from the speaker at the one end of the speaker unit toward the speaker at the other end of the speaker unit.

A noise reducing device comprising:

• a plurality of speaker units each comprising a plurality of speakers arrayed so that the direction of sound emission therefrom faces in a predetermined direction;
• a plurality of microphones, disposed so as to correspond to the respective speaker units, and collecting the sound of a noise and outputting an acoustic signal corresponding to the sound of the noise that has been collected;
• first control signal output means provided to correspond with each of the respective speaker units, and that output, on the basis of the acoustic signal that has been output from a first corresponding microphone that corresponds to the corresponding speaker unit, a first control signal for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the first corresponding microphone;
• second control signal output means provided to correspond with each of the respective speaker units, and that output, on the basis of the acoustic signal that has been output from a second corresponding microphone that corresponds to one of the speaker units that is adjacent to the corresponding speaker unit, a second control signal for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the second corresponding microphone;
• third control signal output means provided to correspond with each of the respective speaker units, and that output, on the basis of the acoustic signal that has been output from a third corresponding microphone that corresponds to the other one of the speaker units that is adjacent to the corresponding speaker unit, a third control signal for emitting a control sound that reduces the direct sound or the diffracted sound of the noise that has been collected by the third corresponding microphone;
• and
• control means, provided so as to input the signals to the respective speaker units, and controlling such that the first control signal is input simultaneously to the respective speakers of the speaker units to which the signals are being input, such that the respective second control signals are input to the speakers of the speaker unit to which the signals are being input with gradually increasing delay times from the speaker at one end of the speaker unit to which the signals are being input toward the speaker at the other end thereof, and such that the third respective control signals are input to the speakers of the speaker unit to which the signals are being input with gradually decreasing delay times from the speaker at the one end of the speaker unit to which the signals are being input toward the speaker at the other end thereof.