The nature of sound
Sound, a manifestation of vibration, travels in wave patterns through solids, liquids and gases.
The waves, caused by vibration of the molecules, follow sine functions, typified by the amplitude and wavelength (or frequency)
Sound waves of equal amplitude with increasing frequency from top to bottom
Reflecting on noise
“Noise" derived from "nausea," meaning seasickness Noise is among the most pervasive pollutants today Noise is unavoidable for many machines We experience noise in a number of ways environmental cause and victim generated by others “second-hand” Noise negatively affects human health and well-being The air into which second-hand noise is emitted and on which it travels is a "commons“, a public good
Pollution
Definition:
The introduction into the environment, by people, of substances or energy liable to cause harm to living creatures or ecological systems.
How did pollution begin?
More sophisticated lifestyles. Growing needs of people. Accelerated rates of human and economic Activities.
WHAT IS NOISE POLLUTION
Sound that is unwanted or disrupts one’s quality of life is called as noise. When there is lot of noise in the environment, it is termed as noise pollution.
Sound becomes undesirable when it disturbs the normal activities such as working, sleeping, and during conversations.
It is an underrated environmental problem because of the fact that we can’t see, smell, or taste it.
World Health Organization stated that “Noise must be recognized as a major threat to human well-being”
Level of tolerance
Normal level of tolerance is 80dbA.
Sound level below and above this is considered to be as noise pollution.
Effects of noise pollution
There are about 25000 hair cells in our ear which create wave in our ear, responding to different levels of frequencies.
With increasing levels of sound the cells get destroyed decreasing our ability to hear the high
References: - www.edugreen.teri.res.in/explore/air http://en.wikipedia.org/wiki/Air_pollution www.controlairpollution.com Environmental studies by R. Rajgopalan www.nlm.nih.gov/medlineplus/airpollution