[Object] To provide a signal processing device capable of effectively using resources for generating a noise cancellation signal. [Solution] Provided is the signal processing device including: a signal analyzing unit configured to analyze a second audio signal based on a first audio signal which is input and a sound collected through a microphone; a cancellation processing unit configured to generate a cancellation signal for canceling the second audio signal; and a parameter generating unit configured to generate a control parameter used in the cancellation processing unit based on a result of analysis performed by the signal analyzing unit.

A low-delay hybrid noise reduction system includes a reference audio receiving device, an error audio receiving device, an audio output device, and an audio processing device. The audio processing device includes a feedforward noise reduction filter module, a feedback noise reduction filter module, and a mixer. The feedforward noise reduction filter module includes a feedforward least mean squares (LMS) filter, a low-stage finite impulse response (FIR) filter, and 1st to Nth-stage biquad filters. The 1st to Nth-stage biquad filters is set on the input end of the low-stage finite impulse response filter to perform low-delay filtering on the reference source audio signal received and outputs to the low-stage FIR filter so as to output the feedforward noise reduction signal through the low-stage FIR filter.

A technique for reducing noise in a listening environment. The technique includes dividing the listening environment into a plurality of zones, where each zone is associated with a different active noise cancellation (ANC) system. A boundary between a first zone included in the plurality of zones and a second zone included in the plurality of zones comprises open space. The technique further includes assigning a plurality of acoustic sensors and a plurality of speakers to the ANC system associated with each zone included in the plurality of zones. The technique further includes, for each zone included in the plurality of zones, acquiring acoustic data via the plurality of acoustic sensors, processing the acoustic data, via a processor, to generate noise cancellation signals, and outputting the noise cancellation signals via the plurality of speakers.

Apparatuses and methods are described to identify desired audio. A first input of an apparatus is configured to receive a main signal. A second input of the apparatus is configured to receive a reference signal. A normalizer is configured to normalize a compressed main signal by a compressed reference signal to create a normalized main signal. A single channel normalized voice threshold comparator is configured to receive as an input the normalized main signal and to output a desired voice activity detection signal.

A noise cancelation system for an unmanned aerial vehicle may have an audio capture module, a metadata module and a filter. The audio capture module may be configured to receive an audio signal captured from a microphone, e.g., on a camera. The metadata module may be configured to retrieve noise information associated with noise generating components operating on the unmanned aerial vehicle (UAV). The filter may be configured to receive the audio signal and noise information from the audio capture module. The filter also may be configured to retrieve a baseline profile from a database based on the noise information. The baseline profile includes noise parameter to filter out audio frequencies from the audio signal corresponding to the noise generating component. The filter may generate a filtered audio signal for output.

An active noise reduction (ANR) earphone system includes a feedback microphone for detecting noise, feedback circuitry, responsive to the feedback microphone, for applying a digital filter K.sub.fb to an output of the feedback microphone to produce an antinoise signal, an electroacoustic driver for transducing the antinoise signal into acoustic energy, a housing supporting the feedback microphone and the driver near the entrance to the ear canal, and an ear tip for coupling the housing to the external anatomical structures of a first ear of a user and positioning the housing to provide a consistent acoustic coupling of the feedback microphone and the driver to the ear canal of the first ear. The acoustic coupling includes a tube of air defined by the combination of the housing and ear tip, having a length L and effective cross-sectional area A such that the ratio L/A is less than 0.6 m.sup.−1.

According to an aspect, an active noise control device includes: a control frequency determinator that determines a frequency of the noise; a reference cosine-wave generator that generates a reference cosine-wave signal having the determined frequency; a reference sine-wave generator that generates a reference sine-wave signal having the frequency of a noise; a first one-tap adaptive filter to which the reference cosine-wave signal is input, the first one-tap adaptive filter having a first filter coefficient; a second one-tap adaptive filter to which the reference sine-wave signal is input, the second one-tap adaptive filter having a second filter coefficient; an adder that adds an output signal from the first one-tap adaptive filter and an output signal from the second one-tap adaptive filter to each other; a secondary noise generator that is driven by an output signal from the adder to generate a secondary noise; a residual sound detector that detects a residual sound generated by interference between the secondary noise and the noise; a simulation signal generator that outputs a simulation cosine-wave signal and a simulation sine-wave signal, the simulation cosine-wave signal and the simulation sine-wave signal being obtained by correcting the reference cosine-wave signal and the reference sine-wave signal using a characteristic in which a transfer characteristic from the secondary noise generator to the residual sound detector is simulated; and a filter coefficient updating unit that updates the first filter coefficient and the second filter coefficient based on an output signal from the residual sound detector, an output signal from the simulation signal generator, the reference cosine-wave signal, the reference sine-wave signal, and the output signal from the adder. The secondary noise is reduced in a space where the residual sound detector is installed.

The disclosure is related to a method and a system for self-tuning active noise canceller (STANC) and a headset apparatus. The headset apparatus is placed on a measurement device to emulate user scenario where the user receives audio signal from the headset. The STANC system receives environmental noise signal from a microphone inside the headset. The output of the STANC system acts as reverse noise signal to suppress the environmental noise signal via a speaker unit. The corresponding mixture signal is defined as an error signal. In a calibration mode, the error signal received from the measurement device can be used to update the STANC parameters. The process will be done when the error signal is lower than a predefined threshold. The final parameters can be saved as default settings for the headset apparatus in a user mode.

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.

According to one embodiment, a noise reduction system for reducing noise including impact noise repetitively generated at a time interval includes the following elements. The error signal generator generates an error signal based on the noise being detected. The delay signal generator has a time delay characteristic and delays a signal, which is generated based on the error signal, to generate a delay signal, the time delay characteristic being determined based on an imaging sequence or pre-scanning by the MRI device and corresponding to the time interval. The control filter generates the first control signal from the delay signal. The loudspeaker unit includes at least one pair of a first filter and a control loudspeaker and a transmission unit.