Signal processing device, program, range hood device, and selection method for frequency bins in signal processing device
AssigneePanasonic Intellectual Property Management Co., Ltd.
InventorsMasaya Hanazono, Wakio Yamada
Life of this patent
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Abstract
Provided are a signal processing device, a program, a range hood device, and a selection method for frequency bins in a signal processing device with which it is possible to reduce the load on computation processing for computing filter coefficients and provide an excellent muting effect even when there are a peak band and a notch band in transmission characteristics from a speaker to an error microphone. A parameter setter sets an update parameter μ such that a filter coefficient W is corrected, only for a first frequency bin that corresponds to a frequency band of a first noise and a second frequency bin that corresponds to a frequency band of a second noise.
Claims8
A signal processing device that is used in combination with a sound input/output device including a first sound inputter that is provided in a space through which a first noise emitted from a noise source propagates and that collects the first noise, a sound outputter that receives an input of a canceling signal and that outputs, to the space, a canceling sound that cancels out the first noise, and a second sound inputter that collects, in the space, a combined sound of the first noise and the canceling sound, the signal processing device comprising:
- a canceling signal generator including a muting filter in which a filter coefficient is set for each of a plurality of frequency bins obtained by dividing a predetermined frequency band, the canceling signal generator receiving an input of a noise signal generated based on an output of the first sound inputter and outputting the canceling signal;
- a coefficient updater that calculates the filter coefficient for each of the plurality of frequency bins based on an output of the first sound inputter, an output of the second sound inputter, and update parameters that are related to a magnitude of an amount of correction for the filter coefficient in processing of repeatedly calculating the filter coefficient;
- and
- a parameter setter that sets the update parameter for each of the plurality of frequency bins,
- wherein the parameter setter sets the update parameter such that the filter coefficient is corrected for a first frequency bin and a second frequency bin among the plurality of frequency bins, the first frequency bin belonging to a frequency band of the first noise, and the second frequency bin belonging to a frequency band of a second noise that is different from the first noise, and
- the parameter setter sets the update parameter such that the filter coefficient is not corrected for a third frequency bin outside an entire bandwidth of the first noise and an entire bandwidth of the second noise, the third frequency bin constituting a notch band in which transmission characteristics in an acoustic path extending from the sound outputter to the second sound inputter drop.
A signal processing method for a device that is used in combination with a sound input/output device including a first sound inputter that is provided in a space through which a first noise emitted from a noise source propagates and that collects the first noise, a sound outputter that receives an input of a canceling signal and that outputs, to the space, a canceling sound that cancels out the first noise, and a second sound inputter that collects, in the space, a combined sound of the first noise and the canceling sound, the signal processing method comprising:
- at a canceling signal generator including a muting filter in which a filter coefficient is set for each of a plurality of frequency bins obtained by dividing a predetermined frequency band, receiving an input of a noise signal generated based on an output of the first sound inputter and outputting the canceling signal;
- at a coefficient updater, calculating the filter coefficient for each of the plurality of frequency bins based on an output of the first sound inputter, an output of the second sound inputter, and update parameters that are related to a magnitude of an amount of correction for the filter coefficient in processing of repeatedly calculating the filter coefficient;
- and
- at a parameter setter, setting the update parameter for each of the plurality of frequency bins,
- wherein the parameter setter sets the update parameter such that the filter coefficient is corrected for a first frequency bin and a second frequency bin among the plurality of frequency bins, the first frequency bin belonging to a frequency band of the first noise, and the second frequency bin belonging to a frequency band of a second noise that is different from the first noise, and
- the parameter setter sets the update parameter such that the filter coefficient is not corrected for a third frequency bin outside an entire bandwidth of the first noise and an entire bandwidth of the second noise, the third frequency bin constituting a notch band in which transmission characteristics in an acoustic path extending from the sound outputter to the second sound inputter drop.
Dependencies are inferred from the claim text.