Noise may cause adverse effects on amenity depending on:
•when and where it occurs
•its duration
•physical characteristics, including the sound pressure level and frequency
•its steadiness
•variations of these properties.
Within urban areas, the background noise environment is most often dominated by traffic. Generally, the higher the traffic volumes nearby, the higher the background noise level. In low traffic areas, background noise may occur naturally from waves, high winds, animals or insects. On average, people will tolerate noise levels up to twice as loud (10dB higher) than the background noise level, except where noise levels adversely affect sleep, or are completely out of character with the existing environment.
The objectives and policies for noise seek to mitigate both the adverse effects of noise and vibration on amenity, and reverse sensitivity effects.