Signal processing apparatus, method, and program
A signal processing apparatus includes a signal processor configured to: generate a first noise reduction signal using an adaptive filter based on a signal output from a first input apparatus, and cause the generated first noise reduction signal to be output by a first output apparatus; and generate a second noise reduction signal using a feedback filter based on a signal output from a second input apparatus, and cause the generated second noise reduction signal to be output by a second output apparatus. The feedback filter has a fixed feedback coefficient. The first input apparatus is located at a first noise-cancellation target location in an environment, and the second input apparatus is located at a second noise-cancellation target location in the environment, which may be different from the first noise-cancellation target location.
1. A signal processing apparatus comprising:
a signal processor configured to:
generate a first noise reduction signal using an adaptive filter on a basis of a signal output from a first input apparatus, and cause the generated first noise reduction signal to be output by a first output apparatus, the first input apparatus being located at a first noise-cancellation target location in an environment, and the generated first noise reduction signal being output to the environment by the first output apparatus, and
generate a second noise reduction signal using a feedback filter on a basis of a signal output from a second input apparatus, and cause the generated second noise reduction signal to be output by a second output apparatus, the feedback filter having a fixed feedback coefficient, the second input apparatus being located at a second noise-cancellation target location in the environment different from the first noise-cancellation target location, and the generated second noise reduction signal being output to the environment by the second output apparatus.
2. The signal processing apparatus according to claim 1 , wherein
the first noise reduction signal targets a noise with a narrow frequency bandwidth, and
the second noise reduction signal targets a noise with a wide frequency bandwidth.
3. The signal processing apparatus according to claim 2 , wherein
the first noise reduction signal targets a noise corresponding to a number of revolutions of a power source that performs a revolving motion, and
the second noise reduction signal targets a noise corresponding to a movement performed by a movable object using the power source.
4. The signal processing apparatus according to claim 3 , wherein the power source is an internal combustion engine or a motor, and the movable object is a vehicle.
5. The signal processing apparatus according to claim 1 , wherein the signal processor:
uses, as the first input apparatus and the first output apparatus, an input apparatus and an output apparatus that have a first fixed relative positional relationship, respectively, and
uses, as the second input apparatus and the second output apparatus, an input apparatus and an output apparatus that have a second fixed relative positional relationship, respectively.
6. The signal processing apparatus according to claim 5 , wherein the signal processor:
uses, as the first input apparatus and the first output apparatus, an input apparatus and an output apparatus that have fixed absolute positions, respectively, and
uses, as the second input apparatus and the second output apparatus, an input apparatus and an output apparatus that have variable absolute positions, respectively.
7. The signal processing apparatus according to claim 1 , wherein the signal processor:
uses, as the first input apparatus and the first output apparatus, an input apparatus and an output apparatus that have a variable relative positional relationship, respectively, and
uses, as the second input apparatus and the second output apparatus, an input apparatus and an output apparatus that have a fixed relative positional relationship, respectively.
8. The signal processing apparatus according to claim 1 , wherein the signal processor uses, as the first input apparatus and the first output apparatus, a plurality of input apparatuses and a plurality of output apparatuses, respectively, the first noise-cancellation target location including a plurality of first noise-cancellation target points corresponding to the plurality of input apparatuses of the first input apparatus.
9. The signal processing apparatus according to claim 1 , wherein the signal processor uses an output apparatus for music reproduction, as the first output apparatus.
10. The signal processing apparatus according to claim 1 , wherein the signal processor uses, as the second input apparatus and the second output apparatus, an input apparatus and an output apparatus, respectively, that are provided on one component among one or more components forming a seat.
11. The signal processing apparatus according to claim 1 , further comprising
a mode setter configured to set an operation mode of the signal processor,
wherein the signal processor switches at least any of an input apparatus used as the first input apparatus, an input apparatus used as the second input apparatus, an output apparatus used as the first output apparatus, or an output apparatus used as the second output apparatus, in accordance with the operation mode set by the mode setter.
12. The signal processing apparatus according to claim 11 , wherein the mode setter sets the operation mode in accordance with a presence or an absence of an output of a signal other than the first noise reduction signal or the second noise reduction signal from an output apparatus that can be used as the first output apparatus.
13. A signal-processing method executed by a processor, the method comprising:
generating a first noise reduction signal using an adaptive filter on a basis of a signal output from a first input apparatus, and causing the generated first noise reduction signal to be output by a first output apparatus, the first input apparatus being located at a first noise-cancellation target location in an environment, and the generated first noise reduction signal being output to the environment by the first output apparatus; and
generating a second noise reduction signal using a feedback filter on a basis of a signal output from a second input apparatus, and causing the generated second noise reduction signal to be output by a second output apparatus, the feedback filter having a fixed feedback coefficient, the second input apparatus being located at a second noise-cancellation target location in the environment different from the first noise-cancellation target location, and the generated second noise reduction signal being output to the environment by the second output apparatus.
14. A non-transitory computer-readable recording medium having a program recorded thereon that, when executed by a computer processor, causes the computer processor to perform a signal-processing method, the method comprising:
generating a first noise reduction signal using an adaptive filter on a basis of a signal output from a first input apparatus, and cause the generated first noise reduction signal to be output by a first output apparatus, the first input apparatus being located at a first noise-cancellation target location in an environment, and the generated first noise reduction signal being output to the environment by the first output apparatus, and
generating a second noise reduction signal using a feedback filter on a basis of a signal output from a second input apparatus, and cause the generated second noise reduction signal to be output by a second output apparatus, the feedback filter having a fixed feedback coefficient, the second input apparatus being located at a second noise-cancellation target location in the environment different from the first noise-cancellation target location, and the generated second noise reduction signal being output to the environment by the second output apparatus.