Measuring Sound
Noise affects us everyday; at home, at leisure, during sleep, when traveling and at work. Taking an active role in making a room soundproof is not only soothing but could also yield noticeable health benefits. Below are a few things you should know about sound and how its measured.
What is STC?
STC Assessment:
Poor: 30 - 39
Good: 40 - 49
Better: 50 - 59
Excellent: 60 - 69

STC stands for Sound Transmission Class. This is a method of gauging sound transmission loss through a wall. The American Standards and Testing Materials criteria is universally accepted by architects, designers, manufacturers, contractors and distributors of acoustical building products. The original acceptability of STC 34 walls must be reconsidered with the advent of increasing noise pollution.

What are dBs?
Noise pollution
In general, noise pollution refers to any noise irritating to one's ear which comes from an external source.

While an STC rating is given in terms of points, the data is given in terms of decibels. A decibel, or dB, is a unit measure reflecting "how loud" a sound is. A sound pressure level of 0 dB represents the threshold of hearing in the most sensitive frequency range of a young, healthy ear, while the thresholds of tickling or painful sensations in the ear occur at about 120 to 130 dB.

Common Sound Noise Level Effect
Hearing begins 0 dB
10 dB Just Audible
Broadcasting Studio 20 dB
Soft whisper 30 dB Very quiet
Quiet Office 40 dB
Light Auto Traffic 50 dB Quiet
Speech 60 dB
Noisy Restaurant 70 dB Intrusive
Alarm Clock 80 dB
City Traffic 90 dB Annoying
Garbage Truck 100 dB
Rock Concert 110 dB Very Loud
Jet Taking Off 120 dB
Thunderclap 130 dB Extremely Loud
Air Raid Siren 140 dB
Rocket Launching 180 dB Hearing loss

Now that we understand roughly what sound is and how sound is measured let's identify the two main noise problem problems that people are dealing with. Read: Identify Your Noise Problem.