What are decibels and how are they measured?

The decibel (abbreviated dB) is the unit used to measure the intensity of sound.  The human ear is very sensitive and can hear everything from a pin drop to a jet engine thousands of feet in the air.  On the decibel scale the smallest audible sound (near silence) is 0 dB.  A sound 1,000 times more powerful than total silence is 30 dB.  According to the U.S. Department of Health and Human Services  exposure to 110 dB for more than 1 minute risks permanent hearing loss. Some examples of dangerous and safe decibel level exposures are:
How are decibels measured?
Decibels are measured with a Decibel Meter. Sound is a vibration passed from one molecule to another and when it reaches our ear the vibration is converted into a sound by our brain. The larger the vibration, the louder we interpret the sound. A decibel meter contains a very sensitive microphone that acts a bit like our eardrums and measures the size of the vibration caused by the sound wave. This is then interpreted into an electrical signal and gives out a reading in decibels.
Summary of the Noise Control Act
sound-meter-300x289
Inadequately controlled noise presents a growing danger to the health and welfare of the Nation’s population, particularly in urban areas. The major sources of noise include transportation vehicles and equipment, sound level metermachinery, appliances, and other products in commerce. The Noise Control Act of 1972 (42 U.S.C. 4901 et seq.) establishes a national policy to promote an environment for all Americans free from noise that jeopardizes their health and welfare. While primary responsibility for control of noise rests with State and local governments, Federal action is essential to deal with major noise sources in commerce, control of which require national uniformity of treatment. EPA is directed by Congress to coordinate the programs of all Federal agencies relating to noise research and noise control.

Ohio’s Noise Ordinance

These sections of the Columbus City Code are most frequently used by police when writing citations for noise violations. Both offenses are minor misdemeanors, punishable by a fine of up to $150.

• 2137.27 loud sound amplification systems prohibited

(a) No operator or passenger of a motor vehicle shall operate, or permit the operation of, any sound amplification system which can be heard outside the vehicle from 50 or more feet when the vehicle is being operated upon a street, highway or other property open to the public for the purpose of vehicle travel or parking.

• 2329.11c Prohibited sounds

(1) No person shall make or allow to be made any unreasonably loud and/or raucous noise in such a manner or at such a volume as to disturb the quiet, comfort or repose of a person of ordinary sensibilities.

Quiet Fence and Noisy Air Conditioning Units
2-Quiet-Fence-blocking-the-noise-to-the-patio1-150x150
Loud A/C units are not only annoying when trying to enjoy time out on your patio, but they can also be disturbing to your neighbors. Quiet Fence with exclusive Hushhh BloX can reduce the decibel level of your A/C unit by as much as 11 decibels! Quiet Fence is also great for reducing the sound of pool pumps and generators too.
Here are some links for more information:

howitworksdaily.com

howstuffworks.com

EPA Government Laws