An aqaurium filter is a very basic machine. Electricity causes a magnetic impeller to spin. Take the aquarium out/off of the tank and take it apart. Plug it in. It should be absolutely silent. If it makes noise with all the parts removed, throw it away. Clean the impeller hole and be sure to seat the impeller properly when you reassemble the filter (this fixes 99% of most noisy filter problems). Noise from a filter is generally a piece of gravel/dirt caught near the impeller, but it can also be a loose impeller fitting or even fluctuating electrical current.
water level in aquarium not high enough or if it is, add some water to the filter equipment and sound will stop : )
When they don't feel like making noise and at night.
Lubricate.
Your chirping smoke alarm is making noise because it is indicating a low battery or a malfunction. To stop the noise, you can replace the battery or reset the alarm according to the manufacturer's instructions.
making
Unplug it.
Bleeding the air from them usually helps.
either replace them or add motor honey to go for a longer perion without noise....
u tell me
Racket
If you get a noise complaint letter then it is best that you stop what ever is making the excessive noise. If the noise is violating the noise pollution law, then you have to stop asap before the police get involved and you get fined. If it is not breaking the law but it is annoying the community then it is best to stop anyway or you will end up with other issues such as neighbors damaging your property when you are not at home.
To stop the buzzing of a doorbell transformer, you can try tightening any loose connections, replacing the transformer, or installing a noise filter.