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.

According to one embodiment, a sound emitting apparatus includes an elastic member, three or more excitation actuators, and a control circuit. The elastic member has an annular shape. The excitation actuators are arranged at a predetermined angular interval on the elastic member and are configured to apply vibration to the elastic member. The control circuit is configured to generate drive signals for driving the three or more excitation actuators. There is a phase difference between drive signals for two excitation actuators separated by the predetermined angular interval, the phase difference depending on an order of a Lobe mode being a vibration mode excited on the elastic member and the predetermined angular interval.

Embodiments include systems with active sound canceling properties, fenestration units with active sound canceling properties, retrofit units with active sound canceling properties and related methods. In an embodiment a system can include a sound cancellation device include a sensing element to detect vibration of a transparent pane and/or a sound input device configured to detect sound incident on the transparent pane, as well as a vibration generator configured to vibrate the transparent pane and a sound cancellation control module. The sound cancellation control module can evaluate the detected vibration of the transparent pane at two or more discrete frequency bands. The sound cancellation control module can cause the vibration generator to vibrate the transparent pane causing destructive interference with sound waves at the two or more discrete frequency bands. Other embodiments are also included herein.

According to one embodiment, a sound emitting apparatus includes an elastic member, three or more excitation actuators, and a control circuit. The elastic member has an annular shape. The excitation actuators are arranged at a predetermined angular interval on the elastic member and are configured to apply vibration to the elastic member. The control circuit is configured to generate drive signals for driving the three or more excitation actuators. There is a phase difference between drive signals for two excitation actuators separated by the predetermined angular interval, the phase difference depending on an order of a Lobe mode being a vibration mode excited on the elastic member and the predetermined angular interval.

Embodiments include systems with active sound canceling properties, fenestration units with active sound canceling properties, retrofit units with active sound canceling properties and related methods. In an embodiment a system can include a sound cancellation device include a sensing element to detect vibration of a transparent pane and/or a sound input device configured to detect sound incident on the transparent pane, as well as a vibration generator configured to vibrate the transparent pane and a sound cancellation control module. The sound cancellation control module can evaluate the detected vibration of the transparent pane at two or more discrete frequency bands. The sound cancellation control module can cause the vibration generator to vibrate the transparent pane causing destructive interference with sound waves at the two or more discrete frequency bands. Other embodiments are also included herein.

Embodiments include systems with active sound canceling properties, fenestration units with active sound canceling properties, retrofit units with active sound canceling properties and related methods. In an embodiment a system can include a sound cancellation device include a sensing element to detect vibration of a transparent pane and/or a sound input device configured to detect sound incident on the transparent pane, as well as a vibration generator configured to vibrate the transparent pane and a sound cancellation control module. The sound cancellation control module can evaluate the detected vibration of the transparent pane at two or more discrete frequency bands. The sound cancellation control module can cause the vibration generator to vibrate the transparent pane causing destructive interference with sound waves at the two or more discrete frequency bands. Other embodiments are also included herein.

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.

Embodiments include systems with active sound canceling properties, fenestration units with active sound canceling properties, retrofit units with active sound canceling properties and related methods. In an embodiment a system can include a sound cancellation device include a sensing element to detect vibration of a transparent pane and/or a sound input device configured to detect sound incident on the transparent pane, as well as a vibration generator configured to vibrate the transparent pane and a sound cancellation control module. The sound cancellation control module can evaluate the detected vibration of the transparent pane at two or more discrete frequency bands. The sound cancellation control module can cause the vibration generator to vibrate the transparent pane causing destructive interference with sound waves at the two or more discrete frequency bands. Other embodiments are also included herein.