Sound volume
Measure loudness in decibels.
Measuring loudness
Loudness is measured in decibels (dB). A sound meter measures decibels. Many phones have a sound meter app. A quiet library is about 40 dB. A busy road is about 80 dB.
Every increase of 10 decibels sounds roughly twice as loud to our ears.
Too loud!
Sounds above about 85 dB can damage your hearing if you listen for a long time. Very loud sounds can damage it straight away. Workers in noisy places wear ear defenders.
Listening to music through headphones at full volume for a long time can damage hearing. A good rule is no more than 60% volume.
Noise pollution
Loud, unwanted sound is called noise pollution. Car horns, traffic and loudspeakers make cities like Dhaka very noisy. Noise can stop people sleeping and make it hard to concentrate.
Bangladesh has rules about noise near schools and hospitals. Drivers should not use horns there.
Quiet places
Trees, walls and thick curtains can help to block noise. Schools and hospitals need quiet zones.
Hospitals and schools are often built away from main roads, and windows can be fitted with two layers of glass to block noise.
What I learnt
- I know that loudness is measured in decibels.
- I know that very loud sounds can damage hearing.
- I can suggest ways to reduce noise.