What Does dB Mean?
dB stands for decibel. It is a logarithmic unit used to measure sound level or signal strength.
Why dB Is Logarithmic
The decibel scale is logarithmic, not linear. This means a small increase in dB represents a large increase in sound energy.
Common Sound Levels in dB
| Sound Source | Sound Level (dB) |
|---|---|
| Whisper | 30 dB |
| Normal conversation | 60 dB |
| Vacuum cleaner | 70 dB |
| Busy traffic | 85 dB |
| Motorcycle | 95 dB |
| Rock concert | 110 dB |
What a 10 dB Increase Means
Every 10 dB increase is perceived as roughly twice as loud to the human ear.
Real-World Examples
- 70 dB feels about twice as loud as 60 dB.
- 85 dB is the level where hearing damage can begin.
- 100 dB can cause hearing damage after short exposure.
Common Mistakes
A common mistake is assuming dB increases linearly. Because it is logarithmic, the scale grows very quickly.
FAQ
Is 80 dB twice as loud as 40 dB? No. The increase is much larger due to the logarithmic scale.
What dB level is safe? Long-term exposure above 85 dB can damage hearing.
Is dB only for sound? No. dB is also used for signal strength and power ratios.