Active noise control apparatus, active noise control method and program
AssigneePioneer Corporation
InventorsManabu Nohara, Akihiro Iseki
Life of this patent
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Abstract
The active noise control device detects noise, and delays a phase of a detected noise signal in a low frequency band. In a non-closed-type noise control device, since there occurs such a phenomenon that the phase of the noise signal advances in the low frequency band, the correction unit performs a correction to cancel the phase advance by delaying the phase. By outputting the noise reduction sound based on the phase-corrected noise signal, the noise is reduced.
Claims14
An active noise control device formed in a non-closed structure and performing a feedback control, comprising:
- a first microphone configured to detect noise and generate a detected noise signal;
- low-boost filter connected to a shelf filter, wherein:
- when the shelf filter is positioned downstream from the low-boost filter, the low-boost filter is configured to delay the phase of the detected noise signal in a low frequency band and the shelf filter is configured to minimize a change in the phase of the delayed detected noise signal inputted into the shelf filter from the low-boost filter and output a filtered noise signal, and
- when the shelf filter is positioned upstream from the low-boost filter, the shelf filter is configured to minimize a change in the phase of the detected noise signal and the low-boost filter is configured to delay the phase of the minimized detected noise signal in a low frequency band inputted into the low-boost filter from the shelf filter and output a filtered noise signal;
- and
- a first speaker configured to output a noise reduction sound which reduces the noise based on the filtered noise signal.
An active noise control method performed by an active noise control device formed in a non-closed structure and performing a feedback control, comprising:
- a noise detection process to detect noise and generate a detected noise signal;
- a first correction process connected to a second correction process, wherein
- when the second correction process is positioned downstream from the first correction process, the first correction process is configured to delay the phase of the detected noise signal in a low frequency band and the second correction process is configured to minimize a change in the phase of the delayed detected noise signal inputted into the second correction process from the first correction process and output a corrected noise signal, and
- when the second correction process is positioned upstream from the first correction process, the second correction process is configured to minimize a change in the phase of the detected noise signal and the first correction process is configured to delay the phase of the minimized detected noise signal in a low frequency band inputted into the first correction process from the second correction process and output a corrected noise signal;
- and
- an output process to output a noise reduction sound which reduces the noise based on the corrected noise signal.
A non-transitory computer-readable medium storing program executed by an active noise control device formed in a non-closed structure and performing a feedback control, the program causing the computer to function as:
- a microphone configured to detect noise and generate a detected noise signal;
- low-boost filter connected to a shelf filter, wherein
- when the shelf filter is positioned downstream from the low-boost filter, the low-boost filter is configured to delay the phase of the detected noise signal in a low frequency band and the shelf filter is configured to minimize a change in the phase of the delayed detected noise signal inputted into the shelf filter from the low-boost filter and output a filtered noise signal, and
- when the shelf filter is positioned upstream from the low-boost filter, the shelf filter is configured to minimize a change in the phase of the detected noise signal and the low-boost filter is configured to delay the phase of the minimized detected noise signal in a low frequency band inputted into the low-boost filter from the shelf filter and output a filtered noise signal;
- and
- a speaker configured to output a noise reduction sound which reduces the noise based on the filtered noise signal.
Dependencies are inferred from the claim text.