Noise control and its overview

Noise control or noise mitigation is a set of strategies for reducing noise pollution or reducing the impact of noise, whether outdoors or indoors.

Overview

The main areas of noise mitigation or abatement are: traffic noise control, building design, urban planning through zoning codes and occupational noise control.Road noise and aircraft noise are the most common sources of ambient noise.Potential noise levels from social activities can continue to impact the health of populations living in or near indoor and outdoor entertainment venues with amplified sound and music that present significant challenges to effective noise reduction strategies .A variety of techniques have been developed to address indoor sound level issues, many of which are encouraged by local building codes.In the best cases of project design, planners are encouraged to work with design engineers to examine road design and building design trade-offs.These techniques include the design of exterior walls, party walls, floor and ceiling assemblies; in addition, there are many specialized methods for suppressing reverberation in special-purpose rooms such as auditoriums, concert halls, entertainment and social venues, dining areas, recording studios and meeting room.

Many of these technologies rely on materials science applications, such as building acoustic panels or using sound-absorbing linings in interior spaces. Industrial noise control is a subset of indoor building noise control that focuses on specific methods of soundproofing industrial machinery and protecting workers on the job.Sound masking is the active addition of noise to make certain sounds less disturbing, as opposed to sound isolation.

Noise control methods

An efficient noise control model is Bolt and Ingard's source, path, and receiver model.Unwanted noise can be controlled by reducing the noise output of the noise source, minimizing the noise as it travels along its path to the listener, and providing the listener or receiver with devices that attenuate the noise.

Source

Various measures are aimed at reducing harmful noise at source. Programs such as Buy Quiet and the National Institute for Occupational Safety and Health (NIOSH) promote the research and design of quiet equipment, as well as the retrofit and replacement of old hazardous equipment with modern technology.

Path

The principle of reducing noise by changing the path applies to changing the direct and indirect paths of the noise.Noise passing through reflective surfaces such as smooth floors can be dangerous.Accessway retrofits include physical materials such as foam, sound absorbing materials, and walls to provide an acoustic barrier, modify existing systems, and reduce unwanted noise.Acoustic enclosures for loud equipment and isolation rooms where staff can remotely control equipment can also be designed.These methods prevent sound from traveling along the path to workers or other listeners.

Receiver

In industrial or commercial settings, workers must follow a proper hearing protection program.Administrative controls, such as restricting access to noisy areas, prevent unnecessary noise exposure.Personal protective equipment, such as foam earplugs or earmuffs to attenuate sound, provide the listener with a last line of defense.