Noise
Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. The dominant form of noise pollution is from transportation sources, principally motor vehicles. The word "noise" comes from the Latin word nausea meaning "seasickness", or from a derivative (perhaps Latin noxia) of Latin noceō = "I do harm", referring originally to nuisance noise.
The mechanism for chronic exposure to noise leading to hearing loss is well established. The elevated sound levels cause trauma to the cochlear structure in the inner ear, which gives rise to irreversible hearing loss. A very loud sound in a particular frequency range can damage the cochlea's hair cells that respond to that range thereby reducing the ear's ability to hear those frequencies in the future. However, loud noise in any frequency range has deleterious effects across the entire range of human hearing.
The outer ear (visible portion of the human ear) combined with the middle ear amplifies sound levels by a factor of 20 when sound reaches the inner ear.
Though it pales in comparison to the health effects noted above, noise pollution constitutes a significant factor of annoyance and distraction in modern artificial environments:
The meaning listeners attribute to the sound influences annoyance, so that, if listeners dislike the noise content, they are annoyed. What is music to one is noise to another.
If the sound causes activity interference, noise is more likely to annoy (for example, sleep disturbance)
If listeners feel they can control the noise source, the noise is less likely to be annoying.
If listeners believe that the noise is subject to third-party control, including police, but control has failed, they are more annoyed.
The inherent unpleasantness of the sound causes annoyance.
Contextual sound. If the sound is appropriate for the activity it is in context. If one is at a race track the noise is in context and the psychological effects are absent. If one is at an outdoor picnic the race track noise will produce adverse psychological and physical effects.