A smart sound appliance which has a noise producing device such as a compressor that is controlled by a controller. The controller receives information from a user indicative of whether the user is in a location to receive those sounds. When the user is in the location to receive those sounds, the controller can take an action to reduce those sounds by either turning off the compressor, or reducing the sound of the appliance in some other way.

A reference microphone for detecting noise is located under a first duct. The noise is in the form of a first plane wave in the first duct. A speaker is located on a top of the first duct. Connected to an upper part of the first duct is a second duct including an error microphone. The first plane wave in the first duct passes through an acoustic path and reaches the second duct. The error microphone detects the sound, and the speaker outputs a second plane wave with an opposite phase for canceling the first plane wave.

Aspects of the invention are directed towards a system and method for noise suppression. One or more embodiments of the invention describe the method comprising steps of receiving noise by a microphone and deriving a noise signal from the noise, the noise produced by a fan of a fire/smoke detection unit while drawing air and detecting the speed of the fan of the fire/smoke detection unit. The method further describes steps of amplifying the noise signal by the amplifier received from the microphone and producing an anti-phase noise signal by shifting a phase of the amplified noise signal received from the amplifier wherein the anti-phase noise signal is dependent on the detected speed of the fan. The method further describes steps of outputting the anti-phase noise signal through a speaker to suppress the noise produced by the fan of the fire/smoke detection unit while drawing the air.

A work machine includes microphones inside the housing. The microphones are configured to collect sound inside the housing, and output sound signals that are electrical signals corresponding to the collected sound. The sound includes an operating noise generated inside the housing due to motion of a machine. The microphones are arranged at different locations inside the housing. The work machine is configured to execute a process related to the operating noise based on the sound signals from the microphones.

The work machine includes a path leading into a housing from an opening. The path is provided to control an airflow generated by motion of a machine. The work machine includes a microphone. The microphone is configured to collect sound in the housing, including operating noise generated in the housing by the motion of the machine. The work machine further includes a structure that defines a receiving space for the microphone along the path through which the operating noise propagates outside the housing. The structure includes an open structure that connects the receiving space with the path and faces downstream in the path. The structure surrounds the receiving space upstream of the open structure in the path.

A food waste disposer system (300) has active noise control of food waste disposer noise that is generated by the food waste disposer (302) when a motor of the food waste disposer (302) is running. The food waste disposer (302) has a food conveying section that conveys food waste to a grinding section. The grinding section has a rotatable shredder plate that is rotated by a motor of a motor section. Active noise sound waves (310) are radiated into an area (313) where the food waste disposer noise is to be controlled at an amplitude and frequency to at least cancel or mask the food waste disposer noise.

A quiet toilet apparatus disclosed. Microphones and circuitry are used to receive and detect one or more virtual point source locations and propagation directions of unwanted toilet noise. Speakers are used to create one or more synthesized wave fronts resulting in cancelation and reduction of unwanted toilet noise. The speakers, microphones and circuitry may be located within a toilet seat of a toilet or at a remote location. A user device or remote device may be connected to the noise reduction toilet apparatus for data recording, collection, reporting, and electronic noise filtering.

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.

A signal processing device includes a coefficient updater configured to calculate a filter coefficient based on a reference signal, an error signal, and an update parameter to set the filter coefficient in a noise cancelling filter. A parameter adjuster adjusts the update parameter according to fluctuation of the reference signal produced from an output of a reference microphone.

A treadmill having a running deck comprising a motor arranged to drive movement of a tread belt, a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to determine an anti-phase waveform based on waveform attributes of a noise emitted from the treadmill and to cause a sound of the anti-phase waveform to be emitted into a surrounding environment.