Which of the following is NOT a source of noise pollution?
- ATraffic noise
- BSoft musicCorrect
- CAircraft sounds
- DNoise from industrial areas
Solution
Concept
Noise is unwanted, loud sound. Soft music is pleasant and low in level, so it is not noise pollution.
Step-by-step solution
1. Noise pollution means unwanted or harmful sound. 2. Traffic, aircraft and industry make loud, unwanted sound, so they are sources of noise pollution. 3. Soft music is low in level and pleasant. 4. So soft music is NOT a source. Answer is (B).
Explanation
Noise pollution is caused by loud and unwanted sound. Traffic, aircraft and industries are the main sources in cities. Soft music is pleasant and at a low level, so it does not cause noise pollution.
Why the other options are wrong
A: Traffic noise is a major source of urban noise. C: Aircraft sounds are very loud near airports. D: Industrial machines produce high noise levels.
Shortcut
Look for the word 'soft' or 'pleasant'. Pleasant sound is not noise.
Common mistake
Thinking all music is noise. Only loud, unwanted music causes noise pollution.
Correct answer: B) Soft music