CANCELLATION APPARATUS, METHOD AND PROGRAM
A cancellation device includes: a first AD conversion unit 2 that converts a noise signal into a digital signal; a second AD conversion unit 4 that converts an error signal obtained by an error microphone arranged in a region in which noise is to be suppressed into a digital signal; a sound signal processing unit 5 that generates a cancellation signal for suppressing the noise on the basis of the digital signal of the noise and the digital signal of the error signal; a DA conversion unit 6 that converts the cancellation signal into an analog signal and causes a cancellation speaker to emit sound based on the analog signal of the cancellation signal; and an internal parameter control unit 8 that dynamically controls an internal parameter to be used in AD conversion or DA conversion according to a statistical feature of the noise.
1 .- 4 . (canceled)
5 . A cancellation device comprising processing circuitry configured to:
convert a noise signal, which is a signal of noise acquired by a reference microphone for acquiring noise, into a digital signal;
convert an error signal obtained by an error microphone arranged in a region in which noise is to be suppressed into a digital signal;
generate a cancellation signal for suppressing the noise based on the digital signal of the noise and the digital signal of the error signal;
convert the cancellation signal into an analog signal and causes a cancellation speaker to emit sound based on the analog signal of the cancellation signal; and
dynamically control an internal parameter to be used in AD conversion or DA conversion by the processing circuitry according to a statistical feature of the noise.
6 . The cancellation device according to claim 5 ,
wherein the internal parameter is at least one of a delay amount, time resolution, and frequency resolution.
7 . The cancellation device according to claim 6 ,
wherein the internal parameter is a delay amount, and
the processing circuitry determines the delay amount that is smaller as a magnitude or temporal change of the noise is larger.
8 . The cancellation device according to claim 5 ,
wherein the processing circuitry determines the internal parameter according to a use scene.
9 . A cancellation method comprising:
a first AD conversion step of converting a noise signal, which is a signal of noise acquired by a reference microphone for acquiring noise, into a digital signal;
a second AD conversion step of converting an error signal obtained by an error microphone arranged in a region in which noise is to be suppressed into a digital signal;
a sound signal processing step of generating a cancellation signal for suppressing the noise based on the digital signal of the noise and the digital signal of the error signal;
a DA conversion step of converting the cancellation signal into an analog signal and causing a cancellation speaker to emit sound based on the analog signal of the cancellation signal; and
an internal parameter control step of dynamically controlling an internal parameter to be used in AD conversion or DA conversion in the first AD conversion step, the second AD conversion step, and the DA conversion step according to a statistical feature of the noise.
10 . The cancellation method according to claim 9 ,
wherein the internal parameter is at least one of a delay amount, time resolution, and frequency resolution.
11 . The cancellation method according to claim 10 ,
wherein the internal parameter is a delay amount, and,
in the internal parameter control step, the delay amount that is smaller as a magnitude or temporal change of the noise is larger is determined.
12 . The cancellation method according to claim 9 ,
wherein, in the internal parameter control step, the internal parameter is determined according to a use scene.
13 . A non-transitory computer readable medium that stores a program for causing a computer to perform as each step of the cancellation method according to claim 9 .