How loud is a Decibel?

A decibel 9DB is a logarithmic unit meaning that you can't add and subtract decibels like whole numbers.

How many decibels a particular item generates speaks to the loudness of that unit. So, an increase of 3dB is a doubling of the "loudness" of the sound, while an increase of 10 dB means that the sound is 10 times as loud. For example a generator that is 72dB is twice as loud as a generator that is 62dB.

Common Items Decibel Ratings from Encarta 2005

Threshold of hearing: 0 dB

Rustling Leaves: 10 dB

Average Whisper: 20 dB

Quiet Conversation: 20-50 dB

Hotel: 40-50 dB

Loud Conversation: 50-65 dB

Traffic on a Busy Street: 65-70 dB

Train: 65-90 dB

Factory Noise: 75-80 dB

Thunder: 90-100 dB

Jet Aircraft at Takeoff: 110-140 dB

Threshold of Pain: 130 dB

Space Rocket on Takeoff: 140-190 dB

Generators

2,500 Watt MultiQuip GA25H at 30 Feet: 70 dBA

6,000 Watt MultiQuip GA6HEA at 30 Feet: 76 dBA

36,000 Watt MQ Power DCA-45SSIU2 at 23 Feet: 66 dBA

36,000 Watt MQ Power DCA-45USI at 23 Feet: 57 dBA