A new definition of noise: noise is unwanted and/or harmful sound. Noise is the new ‘secondhand smoke’.

The words sound and noise are used interchangeably in acoustics, electronics, and physics, but have different connotations when applied to listeners. Sound is defined as vibrations that travel through air or another medium that can be heard when they reach a person's or animal's ears. Noise is defined as unwanted sound. In engineering, noise has the additional connotation of signals varying over time without meaning, whereas sound connotes meaningful signals. Unfortunately, the phrase unwanted sound implies that noise is merely a nuisance, ignoring what is now known about the harmful effects of noise on people and animals. It also implies a value judgment about noise, with a subjective component to the judgment of the listener complaining about noise. Often, there is an additional implication that those who complain about noise are neurotic, weak, self-centered, or have some other psychological or psychiatric problem that for them magnifies the impact of "harmless" sounds that don't bother others. This latter implication is incorrect. Desired sounds can cause auditory damage, and unwanted sound is harmful. Evidence-based noise levels affecting human heath and function are well known. That is why I propose a new definition of noise: Noise is unwanted and/or harmful sound.