# WBBSE Class 6 Geography Solutions Chapter 9 Noise Pollution

Detailed explanations in West Bengal Board Class 6 Geography Book Solutions Chapter 9 Noise Pollution offer valuable context and analysis.

## WBBSE Class 6 Geography Chapter 9 Question Answer – Noise Pollution

Answer the following questions briefly: (2 mark each)

Question 1.
Decibel.
Answer:
The unit to measure the intensity of sound is called decibel. It is measured by the instrument named decibel meter.

Question 2.
Write any one cause of noise pollution.
Answer:
The landing and taking off of aeroplanes can cause serious noise pollution to the residential complexes located at the vicinity of aerodromes.

Question 3.
Write any two measures for controlling noise pollution.
Answer:

• Playing of loudspeakers, bursting of crackers should be restricted to a bearable limit.
• ‘Silence board’ should be hung near hospitals, schools, libraries etc. in order to restrict people from making noise in those areas.

Question 4.
Define noise pollution.
Answer:
When sound turns intolerable, painful and irritable to people, it produces sound pollution.

Question 5.
Write any two harmful effects of noise pollution.
Answer:

• The capability to hear can get reduced gradually as a result of noise pollution.
• Noise pollution can cause high blood pressure, insomnia, heart disease, eye ailments, nerve disorders, gastric and digestive problem.

Identify the correct answers (MCQ): (1 mark each)

Question 1.
Decibel is a …………..
a. musical note
b. musical instrument
c. a measure of sound level
d. none of these
Answer:
c. a measure of sound level

Question 2.
It is physically and mentally uneasy if the sound crosses the limit of ………….
a. 20 dB
b. 40 dB
c. 65 dB
d. 70 dB
Answer:
c. 65 dB

Question 3.
The instrument to measure the intensity of sound is ………….
a. hygrometer
b. decibel meter
c. Anemometer
d. Six’s Thermometer
Answer:
b. decibel meter

Question 4.
Natural source of noise pollution is ………….
a. volcanic eruption
b. bursting of crackers
c. loudspeakers
d. screaching of tyres.
Answer:
a. volcanic eruption

Fill in the blanks with the correct words: (1 mark each)

1. The influence of noise pollution is far greater on _____ folk compared to rural ones.
Answer: urban

2. The rate of illness related to noise pollution is more among _____ people.
Answer: urban

3. It is legally forbidden to blow _____ near school, hospitals.
Answer: horn

4. Exposure to prolonged, high volume and monotonous _____can bring irritation, tiredness and pain.
Answer: sound

5. _____ pollution can cause high blood pressure.
Answer: Noise

If the sentence is true, write ‘T’ and if false write ‘F’ against the following. (1 mark each)

1. The unit to measure the air pollution is called decibel.
Answer: False

2. When sound turns intolerable, painful and irritable to men, it produces sound pollution.
Answer: True

3. Volcanic eruption with sound is an example of man-made noise pollution.
Answer: False

4. Noise pollution is comparatively less in villages.
Answer: True

5. Intensity of sound of vehicles on a busy road is 70 dB
Answer: True

Match the Following (1 mark each)

 Sound Intensity (dB) 1. Loudspeaker a. 300 2. Siren b. 100 3. General talk c. 90 4. Loud music d. 65 5. Jet plane e. 80

Answer:

 Sound Intensity (dB) 1. Loudspeaker e. 80 2. Siren a. 300 3. General talk d. 65 4. Loud music c. 90 5. Jet plane b. 100

### Noise Pollution Class 6 WBBSE Notes

Chapter at a Glance

Pollution : Pollution occurs when something is added to the environment which is harmful or poisonous to people, animals and other living beings.

Noise Pollution : The harmful noise in the environment, such as the sound of cars and buses and trucks in a city or a village, loud speakers, etc. is called noise Pollution. Noise pollution can be defined as the unwanted sound in the atmosphere.

Effects (on Human health) :

• Hearing Problems : Any unwanted sound that our ears have not been built to filter in, can cause problems within the body.
• Sleeping Disorders : Loud noise can certainly hamper our sleeping pattern and may lead to irritation and uncomfortable situations.
• Health Issues : Excessive noise pollution in working areas such as offices, construction sites, and even in our homes can influence psychological health.
• Cardiovascular issues : Blood Pressure levels, cardio-vascular disease and stress related heart problems are on the rise.
• Trouble communicating : High decibel noise can put trouble and may not allow two people to communicate freely.

Introduction

Noise which can be described as an unwanted, untimely, unpleasant ‘voice’ is a pollutant that causes auditory illness [deafness] and non-auditory illness [psychosomatic disorders] over a long period of time. Any sound that causes pain and annoyance is regarded as noise and can be considered as one of the sources of pollution.

Definition of Noise Pollution : Unwanted or unpleasant sound that produces discomfort to humans and causes health hazards could be termed as Noise Pollution. Hence, the disturbing or excessive noise that can harm our activities or damage the balance of human or animal life can be said to be ‘noise pollution’.

Sources of Noise Pollution : High decibel (dB) noise is generated mainly from man-made sources such as horns, sirens, lawnmowers, television, mike, radio, loudspeakers, washing machines, food mixers etc.

Unit of Sound Measurement : Noise is measured by decibel (dB) unit. Noise levels up to 85 decibels are considered safe, but the limit is for eight hours a day, five days a week. Now, if the limit is exceeded even by 3 decibels, it causes damage to the hearing organ. The unit to measure the intensity of sound is called decibel (dB). It is measured by the instrument named decibel meter.

Noisiest Cities in India: In a country like India, and especially in a city like Delhi, people seem to have become inured to high levels of noise and do not foresee the imminent danger. Among the Asian countries, for instance, India has the highest level of noise pollution touching 80-90 decibels, with Delhi, Mumbai and Kolkata being the noisiest cities.

Noise Pollution and its measurement of intensity : The effects of noise pollution can be divided into auditory effects and non-auditory effects. Auditory effects encompass fatigue and deafness.

Non-auditory effects can be understood by a noise of 50 to 60 (dB) interfering with speech.

The Intensity of Different Sounds:

Causes of Noise Pollution:

Outdoor noise can be caused in the following ways especially in the urban areas.

• Poor urban planning : Poor urban planning may give rise to noise pollution.
• Residential and industrial noise pollution : Residential and industrial buildings situated side by side can result in noise pollution in residential areas.
• Noise pollution by sound system and festivals: Loudspeakers, musical bands, festivals and bursting of crackers at different public functions or during festivals disturb the peace and quietness of the environment.
• Noise pollution in cities from different sources : People in cities are exposed to constant blaring of horns, screeching of tyres as buses, trucks, lorries, motor cars and other fast moving vehicles try to overtake each other during busy hours.
• Sound of Aeroplanes : The landing and take-off of aeroplanes can cause serious noise pollution to the residential complexes located at the vicinity of aerodromes.

Others :

• Building of skyscrapers to accommodate the growing population is a common feature in the cities.
• At the construction sites of the multistoreyed buildings, noise produced by different machines and construction tools pose a serious problem in the neighbouring areas.

Silence Board : You must have noticed the ‘silence board’ hung near schools, hospitals and other institutions. This means that it is legally forbidden to blow horns near these institutions.

Intensity of different sounds : Noise about 85-90 decibels are considered to be dangerous. The WHO (World Health Organisation) has recommended a tolerance limit of 45 decibles for noise level at night and 55 decibles for day time.

Intensity and category of sounds and their effects : The effects of noise pollution can be divided into auditory effects and non-auditory effects. Auditory effects encompass fatigue and deafness. Non-auditory effects can be understood by a noise of 50 to 60 dB interfering with speech. Even low level of sound of considerable duration causes annoyance, high blood pressure, nausea, fatigue, anxiety etc. All these lead to a loss of working efficiency.

Others :

• Building of skyscrapers to accommodate the growing population is a common feature in the cities.
• At the construction sites of the multistoreyed buildings, noise produced by different machines and construction tools poses a serious problem in the neighbouring areas.

Silence Board : You must have noticed the ‘silence board’ hung near schools, hospitals and other institutions. This means that it is legally forbidden to blow horns near these institutions.

Intensity of different sounds : Noise about 85-90 decibels are considered to be dangerous. The WHO (World Health Organisation) has recommended a tolerance limit of 45 decibles for noise level at night and 55 decibles for day time.

Intensity and category of sounds and their effects : The effects of noise pollution can be divided into auditory effects and non-auditory effects. Auditory effects encompass fatigue and deafness. Non-auditory effects can be understood by a noise of 50 to 60 dB interfering with speech. Even low level of sound of considerable duration causes annoyance, high blood pressure, nausea, fatigue, anxiety etc. All these lead to a loss of working efficiency.

Noise pollution can be abated if we take the following measures:

• Implementation of laws can control the menace of noise pollution.
• Industrial location should be away from the residential areas. To do this, proper settlement planning is necessary.
• Silencing devices in noise-producing engines such as engines of aircrafts, automobiles, machineries in factories and home appliances could help. It is, at times, very difficult to eliminate high noise level in the case of factories. So, those factories can be set up in remote areas.
• High level of noise can be reduced by covering the room walls with acoustic tiles which act as sound absorbs.
• Persons, especially the workers employed in noise-prone areas, should be given protective devices such as ear plugs and ear muffs.
• Since natural vegetation has a tremendous ability to absorb and dissipate sound energy, trees should be planned along highways and in industrial areas to reduce noise.
• Playing of loudspeakers, bursting of crackers should be restricted to a bearable limit.
• ‘Silence board’ should be hung near hospitals, schools, libraries etc. in order to restrict people from making noise in those areas.
• The old noisy machineries should be replaced by new ones.
• Blowing hom should be prohibited in front of hospitals, near schools, libraries and official buildings.