Decibel (db)

An increment of measurement used to compare measured levels of sound energy (intensity) to the apparent level detected by the human ear. A sound that has 10 times the energy of another sound is said to be 10 decibels louder; 100 times the energy is 20 decibels louder; 1,000 times the energy is 30 decibels louder and so on. Decibel levels are correctly expressed as the number of decibels at a measured distance from the sourse of sound (for example, 125dB at 10 feet)