Test: Environmental Awareness (Noise Pollution) - Software Development MCQ

Noise:

• Noise is defined as unwanted sound which is considered unpleasant, loud, and disruptive to hearing.
• It is indistinguisable from sound as both are vibrabations through a medium, such as air or water.
• The difference rises, when the brain recieves and percievs it.
• Minimum(Faintest) sound level which is audible for humans is 1 dB
• Threshold of discomfort for humans = 110 dB
• Threshold for pain for humans = 140 dB

Additional Information

Permissble noise levels:

Noise pollution may cause or contribute to the following adverse effects:

• Anxiety, stress, nervousness, nausea, headache
• Emotional instability
• Hypertension
• Hearing loss
• Argumentativeness
• Increase in social conflicts
• Depression and fatigue
• Insomnia as a result of lack of undisturbed and refreshing sleep

Noise Pollution: The presence of unpleasant sounds around us is called noise pollution. 

• The noise pollution can be caused by sounds of construction works going around, horns, crackers, loudspeakers, or music with a very loud sound. 
• Such kind of sound can cause health issues like lack of sleep, hypertension (high blood pressure), anxiety, and many more health disorders. 
• Issues related to hearing can also occur due to noise pollution. 
• Whereas the pleasant sound such as the music of our choice is pleasant voice. 
• Other sounds present in option High volume of TV, Crackers and desert coolers can cause noise pollution. 
• So, the correct option is Soft and slow music.

Additional Information

• Steps from prevention from noise pollution:-
  • Use of silencing devices in vehicles 
  • Conducting noisy operations away from the residential area. 
  • The use of automobile horns should be minimised
  • Keeping volume of TV/music system low. 
• The loudness of sound is expressed in decibel. 
  • Sound of more than 80 decibels can cause noise pollution and are painful for the ears.

The correct answer is 2000.

Key Points

• Noise Pollution (Regulation and Control) Rules were formulated by the government of India in 2000 in the exercise of the power conferred under the Environment (Protection) Act, 1986.
• Aim: To curb the menace of excessive noise pollution from various sources to create an ambient atmosphere for healthy living.
  • The noise pollution rules 2000:
    • Prohibit the use of loudspeakers at night.
    • Provide provisions for penalties in case permission for the use of such devices is not sought from a competent authority.
    • Implementing authority: District Magistrate, Police Commissioner and other officers not below the rank of Deputy Superintendent of Police.

The correct answer is 120 dB.

• The loud noises that continue for a prolonged period can cause High blood pressure, Eardrum damage, and Nervous breakdown.
• Noise is unwanted and undesirable sound or noise, an irritant, and a source of stress.
• The sound level meter is used for measuring the intensity of sound.
• The transport sector contributes the maximum noise.
• The roadway noise can be reduced by the use of noise barriers, limitation of vehicle speed, and alteration of roadway surface texture.
• Sound is measured in decibels.
• Noise pollution is considered to be caused by sounds louder than 120 decibels.
• The decibel scale is used for measuring the loudness of sound or noise.
• According to the research, noise pollution is the highest in a low-income neighbourhood.
• The level of sound during normal conversation is 60 dbA.
• The allowed noise level by World Health Organisation (WHO) in residential areas is 50 decibels.
• Noise pollution affects marine animal's behaviour.
• The main source of noise pollution is Heavy machinery and Transportation equipment.

The correct answer is All of the above.

• Sound is the main means of communication in many animals, including humans. A low sound is pleasant and harmless. A loud, unpleasant, or unwanted sound is called noise.
• Sources of Noise Pollution:
  • ​​Industrialization: Most of the industries use big machines which are capable of producing noise.
  • Poor Urban Planning: In most developing countries, poor urban planning also plays a vital role.
  • Social Events: Noise is at its peak in most social events.
  • Transportation: A large number of vehicles on roads, airplanes, trains produce heavy noise.
  • Construction Activities: Construction activities like mining, construction of bridges, dams, buildings, stations, roads, flyovers take place in almost every part of the world.
  • Fireworks: Firework is a common thing during various fairs, festivals, and cultural ceremonies

Additional Information

Effects of noise pollution: 

• Auditory effects:
  • ​Deafness or impaired hearing: Prolonged exposures to noise lead to gradual deterioration of the internal ear and subsequently hearing loss or deafness.
  • Auditory fatigue: It is defined as a temporary loss of hearing after exposure to sound.
• Nonauditory effects:
  • Irritation and annoyance: Noise, sometimes, leads to emotional disturbances and makes people lose their temper.
  • Work efficiency: It has been observed that noise reduces the efficiency of work.
  • Physiological effects: It includes dilation of the pupils, paling of skin, tensing of voluntary muscles, diminishing of gastric secretions, increase in diastolic blood pressure.

Effect (impact) of noise pollution:

(1) Effects (side effects) of noise pollution in humans -

• Hearing loss risk.
• High blood pressure.
• Can affect the circadian rhythm (sleep cycle).
• Irritation.
• High stress. etc.

(2) Effects (side effects) of noise pollution in animals -

• Noise pollution increases mortality risk by altering prey–predator behavior (avoidance or detection).
• Can interfere with navigation.
• Risk of hearing loss.
• Unusual behavior. etc.

Noise level in dB = 10Log₁₀ (Noise in watts)

10 dB = 10Log₁₀ (Noise in watts)

Noise in watts for 10 dB = 10¹ = 10 Watts …(1)

1dB = 10 Log₁₀ (Noise in watts)

Noise in watts for 1 dB = 10^0.1 = 1.26….(2)

P₁/P₂ = 10/1.26 = 7.94 W

Concept:

​Noise pollution:

Noise pollution is generally defined as regular exposure to elevated sound levels that may lead to adverse effects in humans or other living organisms. According to the World Health Organization, sound levels less than 70 dB are not damaging to living organisms. Exposure for more than 8 hours to constant noise beyond 85 dB may be hazardous.

Sources of Noise Pollution:

1). Agricultural machine pollution:

Tractors, thrashers, harvesters, tube wells, powered tillers, etc. have all made agriculture highly mechanical but at the same time highly noisy. Noise level 90 dB to 98 dB due to the running of farm machines have been recorded in the state of Punjab.

2). Household pollution:

The household is an industry in itself and is a source of many indoor noises such as the banging of doors, noise of playing children, crying of infants, moving of furniture, the loud conversation of the inhabitants, etc. Besides these are the entertainment equipment in the house, namely the radio, record-players, and television sets. 

3). Transport pollution:

The automobile revolution in urban centers has proved to be a big source of noise pollution. Increasing traffic has given rise to traffic jams in congested areas where the repeated hooting of horns by impatient drivers pierce the ears of all road users. Heavy trucks, buses, trains, jet-planes, motor-cycles, scooters, mopeds, jeeps noise pollution, etc. are the cause of transport pollution.

4). Defense equipment pollution:

A lot of noise pollution is added to the atmosphere by artillery, tanks, launching of rockets, explosions, exercising of military airplanes, and shooting practices. Screams of jet engines and sonic booms have a deafening impact on the ears.

5). Industrial pollution:

Progress in technology or industrialization has resulted in creating noise pollu­tion. Textile mills, printing presses, engineering establishments, and metal works, etc. contribute heavily towards noise pollution. 

6). Miscellaneous Sources:

The automobile repair shops, construction-works, blasting, bulldozing, stone crushing, etc. are other sources of noise pollution.

Concept:

​Noise pollution:

Noise pollution is generally defined as regular exposure to elevated sound levels that may lead to adverse effects in humans or other living organisms. According to the World Health Organization, sound levels less than 70 dB are not damaging to living organisms. Exposure for more than 8 hours to constant noise beyond 85 dB may be hazardous.

Sources of Noise Pollution:

• Industrial pollution
• Agricultural machine pollution
• Household pollution
• Transport pollution
• Defense equipment pollution 
• Miscellaneous Sources:

Impacts of noise pollution on a human being:

• Physiological effect: Any effect on the natural process of the body like pain in the heart and narrowing of arteries.
• Psychological effect: Affects the thinking, feeling, Emotions overall mental health of a person.
• Physical effect: Affects the external structure of a person.

CPCB (Central Pollution Control Board) has laid down the following permissible noise levels limitations in India for different areas:

The word Noise comes from the Latin word “nausea”. Noise pollution is referred to as an undesirable sound that causes uneasiness to the ear and can result in serious health hazards. Noise pollution can be classified into indoor and outdoor sources.

• Indoor Sources: They include noise produced from radio, television, generators, lawn mowers, electric fans, air coolers, air conditioners, different home, and kitchen appliances, etc.
• Outdoor Sources: They include noise from loudspeakers, industrial activities, automobiles, rail traffic, aeroplanes, farm machines, pump sets, etc.

Key Points

• ​Noise pollution around the educational area can negatively affect the performance of both teachers and students. Noise pollution in the school's environment occurs due to many sources.
• It depends on where the school is built. A school which is located near the city center has a very high noise pollution range because it has many sources that will lead to noise pollution.
• In large residential areas, the sources of noise pollution are limited but in some cases, it still leads to noise problems. The schools must be located in a quiet environment.
• Noise in classrooms can lead to stress and teacher has to raise their voice louder. Hence, teachers teach children to remain quiet in the class and maintain proper silence while learning so that the teacher can teach effectively.

Hence, it is concluded that by maintaining silence in and around the school helps to prevent noise pollution in or around the school.

The correct answer is Central Pollution Control Board.

Key Points

• The CPCB (Central Pollution Control Board) has laid down the permissible noise levels in India for different areas.
• Noise pollution rules have defined the acceptable level of noise in different zones for both daytime and nighttime. 
  • Daytime comprises 6 am to 10 pm, and night is 10 pm to 6 am.
• In commercial areas,
  • Noise limitation has been fixed at 65 dB and 55 dB during daytime and nighttime respectively.
• In residential areas,
  • Limits are 55 dB and 45 dB during daytime and night respectively.
• In industrial areas,
  • The ceiling is fixed at 75dB and 70dB during daytime and nighttime respectively.

Additional Information

• State governments have declared silent zones.
  • These include areas that lie within 100 meters of the premises of schools, colleges, hospitals and courts.
  • The permissible noise limit in this zone is 50 dB during the day and 40 dB during the night.

The correct answer is the Air (Prevention and Control of Pollution) Act,1981.

Key Points

• Section 2(a) of the Air (Prevention and Control of Pollution) Act of 1981:
  • It defines an ‘air pollutant’ as any solid liquid or gaseous substance which may cause harm or damage to the environment, humans, plants, animals, or even damage property.
  • A 1987 amendment to the act also added ‘noise’ to the list of harmful substances.
  • Thus, the provisions of the Air Act, became applicable in respect of noise pollution, also.

Additional Information 

• Air (Prevention and Control of Pollution) Act, 1981:
  • Air pollution is defined as the presence of any liquid or gaseous substances in the atmosphere in such a concentration which tends to be injurious to man, animals, plants or the environment.
  • The Air Act was passed under Article 253 of the Constitution of India and in pursuance of the decisions of the Stockholm Conference.
  • Objective:
    • to provide means for the prevention, control and abatement of air pollution in order to preserve the quality of air.
  • Pollution board's duties: The Central and State Water Boards have been entrusted with the task of controlling and preventing air pollution. 

Concept:

• The vibrations of an object produce sound.
• Our ears perceive sound.
• Unwanted sound, which affects the well-being of individuals/society, is termed noise.
• The level of sound is measured in Decibel (dB).
• It starts from 0.
• Sound up to 25 dB is called silence, as the human ear can’t perceive it.
• 26-65 dB is called quiet.
• Above 66 dB is noise
• Above 75 dB is excessive noise.
• Human health suffers up to 80 dB.
• Above 90 dB is dangerous.

Explanation:

Military Rifle

• The amount of fuel in the cartridge determines how much noise is created when the weapon is fired.
• When the weapon is fired, the exploding propellant creates a pressure spike.
• This travels down the barrel of the gun.
• This changes into a spherically expanding shock wave as it leaves the barrel.
• This supersonic shock wave is the muzzle blast creating noise.
• The sound ranges from 150-175 dB.

Thus, the loudest sound of noise comes from military rifles.

Additional Information

Air raid siren

• The air raid siren produces sound by drawing in the air as it rotates.
• This is then fragmented and thrown out of the horn.
• The faster the rotation louder is the sound
• The contemporary sirens can create sound up to 135 dB at 100 feet.

Loudspeakers

•  Sound is produced by the vibration of the thin diaphragm .
• This disrupts the air pressure around it.
• It is disrupted in the form of the original sound wave.
• An amplified audio signal causes the diaphragm to vibrate.
• The audio signal has the same waveform as the sound wave.
• 75 dB is the maximum permissible loudspeaker decibel limit in India.

Rock music

• The decibel range is 90-120 dB.

The muffler reduces the engine exhaust noise. It is a large cylindrical shaped container, fitted with passages and chambers that absorbs and dampens the noise of exhaust system.

Types of mufflers:

1. Reverse flow muffler:
2. Straight through muffler
3. Baffle type

Key-Points

Noise Pollution:

• Noise Pollution is an unwanted or offensive sound that unreasonably interferes with our daily activities.
• Noise causes stress, leading to illness.
• Therefore any form of noise can be considered pollution.
• It has many sources.
• Most of which are associated with urban activities: road, air and rail transport; industrial noise, construction activity etc.
• Sound is measured in decibels.
• Noise pollution is considered to be caused by sounds louder than 120 decibels.
• Normal conversation is about 60 dB.
• A siren is about 100dB.
• A pneumatic drill used in construction is about 120dB.

Thus, talking is not a source of noise pollution.

These sound waves make the eardrum vibrate. The eardrum is so sensitive to sound vibrations in the ear canal that it can detect even the faintest sound as well as replicate even the most complex of sound vibration patterns.

Key Points

• There are a variety of sounds in our environment, ranging from faint sounds like birdsong and rustling leaves to louder sounds like music, yelling, and industrial noise. 
• This human hearing range is called the audible range. 
• The human hearing range is a description of the pitches and loudness levels a person can hear before feeling discomfort.
• The human ear has a dynamic range from 0dB (threshold) to 120-130 dB.
• This is true for the middle frequency range (1-2 kHz). For lower or higher frequencies, the dynamic is narrowed.
• However, as shown on this graph, all sounds above 90 dB are damaging the inner ear and even doing irreversible damage above 120 dB. (see " Noise: watch out! Danger !")
• The human auditory field (green) is limited by the threshold curve (bottom) and a curve giving the upper limit of sound perception (top).
• At each frequency, between 20 Hz and 20 kHz, the threshold of our sensitivity is different.
• The best threshold (at around 2 kHz) is close to 0 dB.
• It is also in this middle range of frequencies that the sensation dynamics is the best (120 dB).
• The conversation area (dark green) demonstrates the range of sounds most commonly used in human voice perception; when hearing loss affects this area, communication is altered.

Therefore, based on the above descriptions the faintest detectable noise by a healthy human ear is of 0 decible.

The correct answer is Sound from musical instruments.

Concept:

• Sound: A sound is a form of mechanical energy that is transmitted through mediums.
  • Example: sound from musical instruments, man's vocal cord, etc.
• Noise is a sound that is unpleasant or is a loud sound and causes a disturbance.
  • Sound from explosions, factories, vehicles, and a mixture of lots of voices is an example of noise.
• Music: The mixture of different frequencies resulted into an ordered sound is called music.
  • The sound from a musical instrument is an example of music.

Explanation:

• Thus the Sound from musical instruments is not an example of noise. So option 4 is correct.

Noise pollution is that unpleasant sound that causes uneasiness to the ear and can lead to serious health hazards. Increasing population, transportation, industries, factories, and residential areas collectively produce a large amount of noise. It is more prevalent in metropolitan cities compared to suburban areas. Traffic is the main noise pollution in urban areas.

• Sound is measured in units called decibels. The softest sound that healthy ears can hear is 0 decibel (close to total silence).
• A whisper is about 30 dB.
• Normal conversation is about 60 dB.
• A motorcycle engine running is about 95 dB.
• Noise above 70 dB over a prolonged period of time may start to damage your hearing.
• Loud noise above 120 dB can cause immediate harm to your ears.