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Typical noise levels and effects of noise

Short answer

Typical levels range from 0 dB threshold of hearing, 20-30 rustling leaves, 55-65 conversation, 70-80 traffic, 85-95 factory, 110-120 aircraft, to 120-130 pain. Harmful effects include hearing damage, tinnitus, raised blood pressure, stress, annoyance, sleep disturbance, and speech interference.

Give typical sound levels (in dB) at different places and activities. Explain the harmful effects of noise on human beings.

Typical noise levels

Source / placeLevel (dB)
Threshold of hearing0
Rustling leaves, quiet bedroom20-30
Library, quiet residential area at night30-40
Normal conversation (1 m), office55-65
Busy street traffic, restaurant70-80
Heavy truck, factory, loud radio85-95
Motorcycle, power tools, disco95-105
Aircraft take-off at 100 m, thunder110-120
Threshold of pain120-130
Jet engine at close range, firecrackers140

Guideline values (WHO): about 55 dB(A) outdoors in the daytime in residential areas, 30 dB(A) bedroom at night. Industrial limit for an 8-hour exposure is typically 85-90 dB(A).

Effects of noise

  1. Hearing damage: temporary threshold shift and permanent hearing loss from long exposure above 85 dB(A), or sudden very loud sound (acoustic trauma). Tinnitus (ringing in the ears).
  2. Physiological: raised blood pressure and heart rate, stress hormone release, heart disease, headache, digestive disturbance.
  3. Psychological: annoyance, irritability, anxiety, reduced concentration, fatigue.
  4. Sleep disturbance: waking, poor sleep quality.
  5. Communication and performance: speech interference, accidents, reduced work efficiency and learning in children.
  6. Other: damage to buildings from vibration (e.g. sonic boom), and stress in animals.

✓ Answer checked by Claude Opus 5.5 (high effort)

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