To the best of my knowledge, these are strategies and techniques taken to mitigate noise pollution generated by enclosed sources located and/or operating within an urban setting.

Further explanation:

Some of these mitigation approaches might involve government noise ordinances for transportation, traffic, public address systems, and so forth, as well as incorporating noise control mechanism in architectural-based design, vehicular-based design, industrial/production-scale machinery design, and so on (Crocker, 2007).

Typically for urban areas, the ambient noise level that supports speech intelligibility is about 60 - 65 dB (A - weighted rating) of acceptable noise level, but this is hardly ever the case and may vary especially depending on a number of factors including locale, peak hours, frequency/mode of travel, and so on. Furthermore, at about 120 - 150 dB SPL, intelligibility is significantly reduced (Crocker, 1998).

There is no shortage of reference texts that delve deeper into this topic. I hope this helps!

Olabode Olanipekun has given a concise info .

noise pollution abatement management involves all activities that help reduce environmental noise to suggested levels. The prescribed noise levels vary , among countries, . Its different for school districts, business districts and different for night and day time. These laws/guidelines are thought of by government agencies based on scientific research. E.g day and night time noise levels in residential areas are aimed at reducing sleep deprivation of residents and related medical problems. For school district the levels are decided which help reduce distraction and improve attention and learning among students.

In europe, probably these guidelines are issued by The Environmental noise directive (END) 2002/49/EC is a directive from the European Union to give information to the public about the noise levels in their living environment, and to assess and manage environmental noise. The directive was adopted in the year 2000.( Wikepedia)

Similarly In India, central pollution board is entrusted for this purpose.

In USA and elsewhere ISO standards probably is considered.

Apart from policy making, management strategies include engineering solutions and health and hearing monitoring activities.

Engineering solutions include- use of building materials to reduce noise levels with the building, road planning to reduce traffic noise levels

and solutions and modifications to transport vehicles.

Hearing health monitoring is primarily done to industrial workers, where in ear protective devices are prescribed and their hearing levels are monitored periodically.

Concise addition: In The Netherlands land use is strictly regulated in urban planning. Since the 1970's noise control is integrated in urban planning. As the main sources of noise are regarded: road and rail traffic, and industry. Industrial sites, roads and railroads all posess a zone enclosing them; their size depends on the factors determining the sound emission. Within these noise abatement zones, dwellings and other noise sensitive buildings only may be planned after an acoustic survey . The consequences of that investigation can be that: 1. building not permitted or 2. building is permitted under conditions regarding the sound insulation of the envelope of the building.