Noise Pollution

In the Environmental Noise Survey Guidance Document most recently issued by the EPA8 the definition of noise is given (guidance only) as follows: “Any sound, that has the potential to cause disturbance, discomfort or psychological stress to a subject exposed to it, or any sound, that could cause actual physiological harm to a subject exposed to it, or physical damage to any structure exposed to it, is known as noise.” Noise is difficult to define!

Three Facets of Sound: Source Transmission Effect

3 Major Sets of Sources for Indoor Sources and 5 for Outdoor Sources Indoor: apartments & houses office & factory disco(?), entertainment Outdoor: transportation construction, industrial operations humans-shouting, boombox miscellaneous (pets, air conditioners, sirens, garbage can lids, lawn mowers,

Can You H ear ?

AUDIBLE RANGE The ear can hear sounds ranging from 20Hz to 20kHz. It is most sensitive to frequencies between 500Hz and 4000Hz, which corresponds almost exactly to the speech band. Note that this threshold increases significantly with lower frequencies

DBA Description 0 Absolute silence. 25 Very quiet room. 35 Rural night-time setting. No wind. 55 Day-time, busy roadway 0.5 km away. 70 Busy restaurant. 85 Very busy pub. Voice has to be raised to be heard. 100 Disco or rock concert. 120 Uncomfortably loud. Conversation impossible. 140 Noise causing pain in ears.

Naturally, P 1 and P 0 must have The Power of Sound or Intensity

One fan has 50 dB, while adding a second with 56 dB only increases noise level by 1 dB above higher one, or 57 dB.

Effects of Noise Pollution Noise has many effects on humans, including hearing loss, non-auditory physiological effects, sleep disruption, annoyance, communication interference, and other effects.

Noise not only affects hearing. It affects other parts of the body and body systems. It is now known that noise: Increases blood pressure Has negative cardiovascular effects such as changing the way the heart beats Increases breathing rate Disturbs digestion Can cause an upset stomach or ulcer Can negatively impact a developing fetus, perhaps contributing to premature birth Makes it difficult to sleep, even after the noise stops Intensifies the effects of factors like drugs, alcohol, aging and carbon monoxide

Noise controls, hearing protection Changes in machinery, equipment; Enclosures of sources; Damping with absorption; soundproofing Sound insulation, separation, barriers