Noise and What Is Considered Noise

The term "Noise Sensitive Receiver", often abbreviated as NSR, refers to premises that is used for purposes sensitive to noise and requires protection. Examples of noise sensitive receivers are domestic premises, hotels and hostels, educational institutions and hospitals and clinics. Please click on the following diagram to see the enlarged photos. The term "Influencing Factors", abbreviated as IF, refers to industrial areas, major roads or areas that are situated within the boundary of the Hong Kong International Airport. Their presence in the vicinity of a NSR may dominate the ambient or background noise there in such a way that it is impractical to stipulate too low a noise limit for either planning or control purpose.

The term "industrial area" refers to an area which consists of a number of factories or industrial establishments; or an establishment which is having industrial operation or operations of a significant scale. A "major road" means a road which has a heavy and generally continuous flow of vehicular traffic and, in normal circumstances, means a road with an annual average daily traffic flow in excess of 30,000 vehicles. Where a major road has an unusually low traffic flow rate (less than 300 vehicles per hour) at the time of day under consideration, it shall not be considered as an IF at that time. The term "Degree to which NSR is affected by IF" refers to how the NSR is being affected by the IF. It can be either :

(a) Not affected, or

(b) Indirectly affected, or

(c) Directly affected.

For "directly affected", the NSR is at such a position that noise generated by the IF is readily noticeable at the NSR and is a dominant feature of the noise climate of the NSR.

"Indirectly affected" means that the NSR is at such a location that noise generated by the IF, whilst noticeable at the NSR, is not a dominant feature of the noise climate of the NSR. For "not affected", the NSR is at such a location that noise generated by the IF is not noticeable at the NSR. The "Area Sensitivity Rating", abbreviated as ASR, is a rating of the area in which the NSR is located. The ASR can be either A, B or C and is derived from the following table after knowing the Type of Area Containing NSR, any presence of IF, and "Degree to which NSR is affected by IF". Please click on the demo button to read the details.

Noise pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. As with other forms of energy pollution (such as heat and light pollution), noise pollution contaminants are not physical particles, but rather waves that interfere with naturally-occurring waves of a similar type in the same environment. Thus, the definition of noise pollution is open to debate, and there is no clear border as to which sounds may constitute noise pollution. In the most narrow sense, sounds are considered noise pollution ...