Noise pollution is defined as unwanted and elevated sound that occurs in the day to day life. Noise pollution is generally associated to noises coming from construction, airplanes, and highway noises, but is everywhere including our homes and workplaces.
At certain level (volume/pitch) of sound, it can cause damage to your eardrums causing discomfort thus causing stress. Britannica noise pollution article does a good job explaining the science. Overall, noise is just a nuisance and can cause: