decibel

Everyday

(science) A decibel is a unit for measuring how loud a sound is. tree →

In the lessons

In science, sounds are measured in decibels: whispering is about 30 dB, normal talk about 60 dB, a busy road about 80 dB, a rock concert over 100 dB. Long exposure above about 85 dB can damage hearing — wear ear protection and keep headphones at safe volume.

Examples

• A whisper is about 30 decibels. tree →
• The concert reached 110 decibels. tree →
• Sounds above 85 decibels can harm your hearing over time. tree →
• We measured the playground noise in decibels with an app. tree →
• The teacher's whistle was very high in decibels. tree →
• Lower the volume on your headphones to keep the decibels down. tree →

Note

Short form: dB. Maths trap: the decibel scale is not like a ruler — adding 10 dB means about ten times more sound energy and sounds roughly twice as loud, so 80 dB is much more than «a bit» louder than 70 dB.