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CONTROL OF NOISE POLLUTION

CONTROL OF NOISE POLLUTION

NOISE:

What Is Noise ? The term noise may be defined as an

unwanted sound at a wrong time and a wrong place. Although noise is undesirable it could be meaningful or meaningless.

Cry of baby or screaming of person Or meaningless noise is disturbing and

annoying.

ADMINISTRATIVE CONTROLS:

These are essentially short term controls which are aimed at protecting the workers overexposed to noise levels of about 90 dBA before the management can plan and implement long term solutions.

ENGINEERING CONTROLS:

In order to control high noise levels one or more of the following three methods may be necessary

1) suppression of the noise at source 2) path control, and 3) protection of the personnel

SUPPRESSION OF THE NOISE:

This is an effective and economical approach particularly in situation where the noise levels are very high. Such situation arises with devices such as compressor, cooling fans, valves etc.

PATH CONTROL:

After taking all possible steps to suppress the noise at source, further engineering controls are directed at the treatment of the major noise transmission paths from the source.

SOUND ABSORPTION:

Absorption of sound energy is achieved by one or more of the following mechanisms:

A) friction between the fibers of a porous fibrous material

B) Absorption in the voids of porous, non fibrous material and

C)absorption within narrow entries to an air space

VIBRATION CONTROL: Vibration isolation comprises of

protecting a supporting structures from force excited vibrations generated in an associated mass or protecting a mass from motion excited vibration generated in the supporting structure.

ACOUSTIC ENCLOSURES: In the context of noise control, the term

enclosure broadly refers to any method used for artificially impending the free flow of acoustic energy away from the source.

As a rough guide it may be taken that whenever an overall sound reduction of about 15 dBA is desired.

NOISE BARRIERS: Construction of thick and high (>2m)

barrier, covered with an acoustic material on the source side, block the path of directly transmitted sound from the source and provide protection particularly from high frequency noises.

MUFFLERS AND SILENCERS:

A muffler or a silencer is a pipe or duct treated or shaped for reducing sound transmission. Mufflers or silencers are classified into two categories

The dissipative and Reactive.

MUFFLERS AND SILENCERS: A muffler or a silencer is a pipe or duct

treated or shaped for reducing sound transmission. Mufflers or silencers are classified into two categories

The dissipative and Reactive.

ACOUSTICAL ABSORPTIVE MATERIAL

An ideal acoustical absorbent should have the following properties.

1) High noise reduction coefficient.2) Adequate strength. 3) Smooth surface for low fluid friction.4) Fireproof.5) Free from odors.6) Good light reflectivity.7) Good and decorative effect

Thank You!