Noise

From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water.

[15][16][17] Urban noise is generally not of an intensity that causes hearing loss but it interrupts sleep, disturbs communication and interferes with other human activities.

[18] There are a variety of mitigation strategies and controls available to reduce sound levels including source intensity reduction, land-use planning strategies, noise barriers and sound baffles, time of day use regimens, vehicle operational controls and architectural acoustics design measures.

Certain geographic areas or specific occupations may be at a higher risk of being exposed to constantly high levels of noise; regulation may prevent negative health outcomes.

Noise regulation includes statutes or guidelines relating to sound transmission established by national, state or provincial and municipal levels of government.

[24] The National Institute for Occupational Safety and Health (NIOSH) provides recommendation on noise exposure in the workplace.

The following year, OSHA required employers to provide a hearing conservation program to workers exposed to 85 dBA average 8-hour workdays.

[30][31] Additionally, in the European Union, underwater noise is a pollutant according to the Marine Strategy Framework Directive (MSFD).

[32] The MSFD requires EU Member States to achieve or maintain Good Environmental Status, meaning that the "introduction of energy, including underwater noise, is at levels that do not adversely affect the marine environment".

Depending on duration and level of exposure, noise may cause or increase the likelihood of hearing loss, high blood pressure, ischemic heart disease, sleep disturbances, injuries, and even decreased school performance.

[35] When noise is prolonged, the body's stress responses can be triggered; which can include increased heartbeat, and rapid breathing.

This can be especially important for professionals working in settings with consistent exposure to loud sounds, such as musicians, music teachers and audio engineers.

But the HPD (without individual selection, training and fit testing) does not significantly reduce the risk of hearing loss.

[48] Avant-garde composer Henry Cowell claimed that technological advancements have reduced unwanted noises from machines, but have not managed so far to eliminate them.