Physics (NTSE/Olympiad)  

5. Sound

Characteristic of Sound - Loudness

(A) Loudness
Loudness of a sound depends on the amplitude of the vibration producing that sound. Greater is the amplitude of vibration, louder is the sound produced by it.
The loudness of a sound also depends on the quantity of air that is made to vibrate. Loudness of sound is measured in decibel (dB) unit.
Sound dB Loudness
Rocket at take off 200 Dangerously loud
Aircraft engine 100–200 Painfully loud
Pneumatic drill 100 Very loud
Heavy traffic 90 Very loud
Loud music 90 Very loud
Ordinary coversation 40-60 Moderate
Whisper 20 Faint
Rustling of leaves 10 Very faint


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